Great Basin Naturalist, vol. 45, no. 3, pp. 337-390 (1985).

ABSTRACT

One problem with the Crystal Ball Cave assemblage is that it is impossible to separate fossil bones from Recent bones using superposition, because the sediments in which they are found are shallow and unstratified. Some of the best specimens of extinct species were found on the surface by early expeditions. The cave seems to have been accumulating fossils continuously from some date in the past, when an entrance was formed, until the present. The purpose of radiometric dating was to establish when fossils were first deposited and if the rate of fossil deposition has been uniform since then.

Four bone samples were sent to Geochron Laboratories, Cambridge, Massachusetts, for carbon-14 dating. Because of the small size of bones in the assemblage, these samples (which included some of the largest recovered) were just over 25 grams, the minimum weight suggested for dating. Two were of small extinct horses: a thoracic vertebra (BYUVP 7687) and a distal metapodial epiphysis (BYUVP 7568); and two were fragments of unidentified limb bones of large mammals. Geochron Laboratories cleaned and washed the four samples in acetic acid to remove adhering materials then crushed them and soaked them in agitated acetic acid for 24 hours to remove normal carbonates. The samples were then hydrolized under vacuum with hydrochloric acid to dissolve bone apatite and evolve its carbon dioxide for collection. The carbon dioxide samples were converted to methane and counted in a low background beta counter (with C-13 correction), and dates were based on the Libby half life (5570 years). The ages reported are listed in table 2. The oldest date of "over 23,000 Y.B.P." was given because no C-14 was detected in that sample.

The oldest date of 23,000+ Y.B.P. gives a minimum age for the time fossils first entered the cave. The youngest horse bone date of about 19,000 Y.B.P. gives a maximum age for the loss of that species from the area, although other studies have shown that small horses lived beyond 10,370 Y.B.P. in Idaho and until about 8,000 Y.B.P. in Arizona and Alberta, Canada (Kurten and Anderson 1972, 1980, Martin 1967). Otherwise the four dates give only a general age for the assemblage and provide no information about the antiquity of individual taxa. The fact that all four dates are over 12,000 Y.B.P. suggests that bones, at least of large mammals, may have been deposited more frequently during the late Pleistocene than during the Recent. If so, this could be due to a greater abundance of the animals themselves, a change in what animals (or other processes) deposited the fossils, or the former presence of larger or additional entrances.

Thirty radiometric dates have been reported from the Smith Creek Canyon sites (Thompson 1979, Thompson and Mead 1982, Valastro et al. 1977), and they demonstrate that accumulation of fossils there was concurrent with fossil deposition at Crystal Ball Cave. The two oldest Smith Creek dates are 28,650 Y.B.P. (Smith Creek Cave) and 27,280 Y.B.P. (Ladder Cave), which correlate well with the date of "over 23,000 Y.B.P." from Crystal Ball Cave. The other 28 Smith Creek Canyon dates are younger than 18,000 Y.B.P. with the majority being from 10,000 to 13,000 Y.B.P. The mean age of the four dated Crystal Ball Cave specimens is considerably older than the mean age of dated specimens from any of the Smith Creek Canyon sites, suggesting that its major period of fossil deposition was earlier; but a sample size of four dates is not statistically significant enough to demonstrate this.

The Pleistocene-Recent boundary was a period of intense climatic and faunal change. The changes at this fossil site were particularly drastic due to its close proximity to Lake Bonneville which was present during most of the time that fossils were being deposited. According to Currey (1982) the Bonneville Level terraces at Gandy are at an elevation of 5165 feet (1565 meters), showing that the lake rose to 644 feet (195 meters) below and 1 mile (1.7 km) east of Crystal Ball Cave and filled Snake Valley as far as 36 miles (60 km) south of the cave (see figure 1). My previous statement that Gandy Mountain was once an island in Lake Bonneville (Heaton 1984) was based on data from an earlier study and is unconfirmed. Lake Bonneville started its last cycle of filling prior to 26,000 Y.B.P., and it reached its highest level (Bonneville Level) about 16,000 years ago (Currey 1982, Scott et al. 1983). The lake remained at the Bonneville Level until 14,000 or 15,000 Y.B.P. when the flood at Red Rock Pass, Idaho dropped the lake to the Provo level, where it remained until about 13,000 Y.B.P. (Currey 1982, Scott et al. 1983). At the Provo level the lake had only a shallow arm extending southward into Snake Valley to a point 5 miles (8 km) east of Crystal Ball Cave (Currey 1982). Further lowering of the lake after 13,000 Y.B.P. caused its quick retreat northward out of Snake Valley to a point 40 miles (65 km) northeast of the cave by 10,300 Y.B.P. (Currey 1982). Based on these dates Lake Bonneville was very close to Crystal Ball Cave for at least half the time that fossils were being deposited and within Snake Valley for about two-thirds of the time or longer. Then within a few thousand years, the fossil site changed from being near the shore of a large continental lake to being in a dry desert, as it is today.

In addition to Lake Bonneville, many pluvial lakes filled the valleys of Nevada including one just west of the Snake Range, 18 miles (30 km) west of Crystal Ball Cave (Mifflin and Wheat 1979). Based on studies of temperature and precipitation correlation, Mifflin and Wheat (1979) estimated that development of pluvial lakes in the area involved a temperature decrease of 5 F (3 C). Lower temperatures and higher annual precipitation caused floral boundaries to move lower in elevation and latitude during the Wisconsinan glacial (Thompson and Mead 1982, Wells 1983). This shift had a dramatic effect on small boreal mammals in the Great Basin because it allowed them to disperse between ranges, whereas now the intermontane basins act as absolute barriers (Brown 1971, 1978, Harper et al. 1978). Brown (1971, 1978) demonstrated that distribution of small boreal mammals is relectual from the Wisconsinan glacial and not a case of colonization-extinction equilibrium. The Crystal Ball Cave fauna shows what taxa have been extirpated from the Snake Range since the Wisconsinan glacial and documents northward shifts in the ranges of several species at the close of the Pleistocene.

Another striking feature of the late Pleistocene is the well-documented megafaunal extinction. At the end of the Wisconsinan glacial 41 species of large mammals went extinct--3 times more than at the end of any of the other Pleistocene glacials (Kurten and Anderson 1980). Different workers have attributed this to the rapid post-glacial climatic shift (Martin and Neuner 1978, Webb 1969) and to overkill by Early Man (Martin 1967, Mosimann and Martin 1975). The Crystal Ball Cave assemblage contains several of these extinct taxa, but the fact that it lacks human association and stratigraphic control makes it unable to provide any substantial data to resolve this controversy.

Consideration needs to be given to the role Crystal Ball Cave played as a shelter and the way fossils got into the cave. When the cave was discovered in 1956, the east entrance was a 3-foot (1-meter) diameter opening in solid rock, half filled with soft soil, which sloped downward into the large entrance chamber (see figure 3). Several 1-foot (0.3-meter) diameter entrances (which are often filled with woodrat nesting material) also exist just north of the east entrance. The north entrance was completely filled with debris, which if removed could make it 8 feet (2.5 meters) high and 20 feet (6 meters) wide. It could have been a large important entrance when the earlier bones were being deposited, but several factors preclude this. First, there are very few fossils in the deep dry sediments of the north half of the cave; the rich bone deposits are in the south half. Second, the fossil assemblage provides no evidence that there ever was a large entrance since large mammals are represented only by their smallest elements. If the north entrance ever was large it was probably prior to deposition of the fossils under study.

Neotoma lepida, Peromyscus maniculatus, and Plecotus townsendii were captured live inside the cave, so their presence in the assemblage is easy to explain. Other small mammals could also have lived in the cave or used it as a shelter. Small carnivores and scavengers could have brought their prey into the cave to eat. The presence of only the smallest isolated elements of large mammals suggests that these bones were brought into the cave individually after the carcasses deteriorated. Small carnivores could have contributed to this, but it is my opinion that these bones were taken into the cave primarily by wood rats, since they are known to take materials into the cave now and since all the bones in the assemblage are small enough for a wood rat to transport. Because the cave has small entrances and because the bones are found far within the cave, it is very unlikely that birds transported prey inside. There is also no evidence that prehistoric humans brought material into Crystal Ball Cave. This suggests that the species found in the assemblage lived and died in or near the cave and were not transported long distances, as could have occurred at Smith Creek Cave (see Bryan 1979, Harrington 1934).

It is unusual for caves to have their richest bone deposits far inside the cave rather than near an entrance. The east entrance takes in water during storms, and other areas are damp from seepage. Sites 1 and 2, which contain the richest bone deposits, are in one of the driest areas of the cave and are just outside the zone of total darkness when the sun shines through the east entrance. North of Sites 1 and 2 the passage constricts and enters total darkness but remains dry. Wood rat nests are particularly common at Sites 1 and 2, which helps explain why rich bone deposits are present if wood rats play an important role in getting them there. The extremely dry conditions at Sites 1 and 2 and their proximity to the east entrance, which I consider the primary entrance, are probably the reason why these sites have been so productive. Rarity of fossils nearer the east entrance is probably due to poorer preservational conditions and poorer sites for wood rat dwellings. Lack of rich bone deposits in the northern half of the cave is probably due to constricted passages and greater distance from a late Pleistocene entrance.

Kingdom Plantae
Division Tracheophyta
Class Gymnospermae
Family Ephedraceae
Ephedra cf. viridis

Material--Two stem fragments.

Class Angiospermae
Family Asteraceae
Chrysothamnus sp.

Material--One branching stem fragment.

Haplopappus nanus

Material--One group of involucres, 4 single involucres.

Perityle stansburii

Material--Four involucres on stem fragments.

Family Brassicaceae

Material--Two stem fragments, 2 stem fragments with empty seed capsules, 4 empty seed capsules.

Family Cactaceae
Opuntia sp.

Material--Twelve spines.

Family Caprifoliaceae
Symphoricarpos cf. longiflorus

Material--One branching stem fragment, 4 straight stem fragments, 56 leaves and partial leaves.

Family Poaceae
cf. Elymus

Material--Two fruits.

cf. Panicum

Material--Three connected fruits, 3 rachis fragments.

Discussion--About 250 small plant fragments were recovered from the Crystal Ball Cave sediments by the same process that small bones and teeth were recovered. From among them Howard C. Stutz (1984 personal communication), a botanist at Brigham Young University, identified the above taxa. All of the taxa identified still live in the immediate area of Crystal Ball Cave (partly because a sample of plants from immediately around the cave comprised most of the comparative material), so they do not document any floral changes since the Pleistocene. Further research could turn up additional taxa since not all the plant fragments were identified.

The great abundance of Symphoricarpos compared to the other plant taxa recovered is noteworthy. H. C. Stutz (1984 personal communication) found a thicket of Symphoricarpos at the bottom of a cliff in the nearby House Range which was full of rodent nests and burrows. This suggests that this plant is a favorite nest building material for rodents, and wood rats may have brought a lot of it into Crystal Ball Cave for that purpose.

No pollen analysis has been done at Crystal Ball Cave, and no pollen was noticed in the cave sediments studied. A more extensive search could turn up pollen, however, and since plant fragments are rare in the sediments, it could help identify what plants inhabited the area during the Pleistocene.

Kingdom Animalia
Phylum Mollusca
Class Gastropoda
Order Pulmonata
Family Helicidae
Oreohelix strigosa

Material--Nine complete shells ranging from 3 to 10 mm in diameter.

Discussion--These land snails, which still inhabit the Snake Range, live in moister conditions than those at Crystal Ball Cave today (Chamberland and Jones 1929), so they are probably late Pleistocene or early Recent in age. Since there are only nine specimens, they were probably never abundant near the cave and may have even been transported some distance before being deposited.

Phylum Arthropoda
Class Crustacea
Order Isopoda
Family ? Armadillidae

Material--Partial dried shell.

Discussion--Pill bugs are native to North America (S. L. Wood 1984 personal communication), and little work has been done on them. Representatives of several families including family Armadillidae presently live in Utah, but the partial specimen did not allow further identification. These terrestrial crustaceans inhabit moist recesses throughout Utah and Nevada today, so the presence of this specimen is not surprising although little can be said about its age.

Class Insecta
Order Coleoptera
Family Scarabaeidae
Aphodius distinctus

Material--Complete dried specimen.

Discussion--This small beetle lives in cattle dung and was introduced from Europe in Recent times (S. L. Wood 1984 personal communication). It is therefore Recent in age and has little significance to the assemblage.

Phylum Chordata
Class Osteichthyes
Infraclass Teleosti

Material--Thirty-seven amphicoelous vertebrae ranging from 1 to 5 mm in diameter and length (BYUVP 7939-7973).

Discussion--Presently the closest water body to Crystal Ball Cave is Gandy Spring on the south side of Gandy Mountain. This spring emits voluminous warm (81 F, 27 C) water which is high in calcium (J. C. Bates 1983 personal communication). Small minnows were the only native fish found living in the stream that exits Gandy Spring, but bass and blue gill were introduced in the 1960's and still survive; carp are also found in reservoirs in the area (J. C. Bates 1984 personal communication). Mead et al. (1982) reported Salmo and Gila from nearby Smith Creek Cave which is higher in elevation and farther from a perennial water source than Crystal Ball Cave, and Smith (1978) and Smith et al. (1968) reported Pleistocene fish from Lake Bonneville deposits.

A dichotomy in the size of the fish vertebrae from Crystal Ball Cave suggests that at least two species are represented, but no attempt at generic identification has been made. The possibility that these vertebrae are Recent cannot be eliminated, but they probably represent fish that lived in Lake Bonneville when it was at or near the Bonneville level, or in perennial Pleistocene streams in the area. In any case they had to be transported up Gandy Mountain to the cave site. Carnivores or scavengers could have done this, and wood rats could have taken them inside the cave.

Class Reptilia
Order Squamata

Material--Two hundred and sixty-five lizard and snake jaws (BYUVP 8004-8217). Postcranial material is also represented but has not been separated from that of mammals.

Discussion--The reptile specimens have not yet been studied but will be reported in a future paper by Jim I. Mead and Timothy H. Heaton. The reptiles recovered from the deeper levels of Smith Creek Cave demonstrate that their present distribution in the Great Basin is more ancient than previously believed (Brattstrom 1976, Mead et al. 1982). The large number of reptile jaws from Crystal Ball Cave will help establish what species have been extirpated from the area, but unless dated individually, they will not help establish the antiquity of their ranges.

Class Aves

Material--Six hundred and eleven specimens representing all skeletal elements of small passerines and skull and vertebrae fragments of larger forms (BYUVP 6606, 8301-8888, 8911-8933, LACM 123655).

Discussion--The bird specimens have not yet been studied but will be reported in a future paper by Steven D. Emslie and Timothy H. Heaton. Miller (1982) reported ? Aquila from Crystal Ball Cave from among this same material. Based on their large size, three bird vertebrae fragments (BYUVP 8326-8328) can possibly be assigned to the extinct Teratornis incredibilis, originally described from nearby Smith Creek Cave (Howard 1952).

Class Mammalia
Order Insectivora
Family Soricidae
Sorex sp.

Material--One maxilla pair with all teeth (BYUVP 5321). Another 5 partial maxillae and 27 partial dentaries (some with teeth, BYUVP 5300-5320, 5322-5332) were recovered that cannot be generically identified but compare favorably with Sorex.

Discussion--Identification was based on the presence of 5 unicusp teeth behind the upper incisor, the first 4 of which taper slightly in size posteriorly and are visible laterally, and the last of which is tiny, peglike, unpigmented, and not visible labially. Microsorex and Blarina also have 5 unicusp teeth in each maxilla, but Microsorex has only the first 3 visible laterally and Blarina has the third and fourth of subequal and smaller size than in Sorex. Notiosorex and Criptotis, the other two North American genera, have only 3 and 4 unicusp teeth in each maxilla respectively (Hall 1981). All the other soricid specimens are either lower jaws and teeth, which I was unable to distinguish at the generic level, or are maxillae without the diagnostic unicusp teeth. All these soricid specimens compare well with S. vagrans and S. palustris, which presently live in the region of the cave (Hall 1981), but no dental character could be found to distinguish them.

Order Chiroptera
Family Vespertilionidae
Myotis sp.

Material--Two palates without teeth (BYUVP 5340, 5357), anterior portion of right maxilla with P4/, M1/ (BYUVP 5338). Twelve right dentaries (BYUVP 5336, 5341-5346, 5352, 5353, 5358-5360) and 12 left dentaries (BYUVP 5339, 5347-5349, 5354-5356, 5361-5364, 5366) were recovered which are Myotis or Plecotus.

Discussion--Myotis maxillae have the diagnostic presence of two
small unicusp premolars following the incisor, as opposed to one or none in all other vespertilionids. Dentaries of Myotis and Plecotus are virtually identical, both having the dental formula of I/3, C/1, P/3, P/3 and similar size and proportions, and no character could be found to separate them. Dentaries of Lasionycteris and Pizonyx also share this tooth formula but are considerably larger. Myotis has not been reported living in Crystal Ball Cave, but M. lucifugus, M. evotis, M. thysanodes, M. volans, and M. subulatus are all found in the region (Hall 1981). Little work has been done to separate species of Myotis dentally, and I was unable to find any species variation that was greater than individual variation.

? Plecotus townsendii

Material--Twenty-four dentaries were recovered of Myotis and/or Plecotus (as listed and discussed above).

Discussion--Plecotus townsendii is the only bat reported living in the cave. Specimens were captured by Halliday (1957) and by myself in 1982 and 1983. Halliday (1957) and other workers have referred this bat to Corynorhinus rafinesquii, but Handley (1959), in his synthesis of the big-eared bats, considers both Corynorhinus and Idionycteris as only subgenera of the European genus Plecotus. He also regards P. rafinesquii (presently in southeastern U.S.) and P. townsendii (presently in western U.S.) as two distinct species. P. mexicanus, the third living species of the subgenus (Corynorhinus), and P. hyllotis, the only member of the subgenus (Idionycteris), both inhabit Mexico and north into the southern tip of Arizona. Two extinct Pleistocene species of the subgenus (Corynorhinus) are also recognized: P. alleganiensis from Cumberland cave in Maryland and P. tetralophodon from San Josecito Cave in Mexico (Handley 1959). Handley (1959) lists no characters to distinguish the dentaries of different species of Plecotus, but the bats living in the cave are clearly P. townsendii.

Lack of positive evidence for this species in the Crystal Ball Cave assemblage could represent lack of chance preservation or a recent change in the species that inhabit the cave. Since the assemblage contains indistinguishable Pleistocene and Recent specimens, even if the lower jaws could be identified as Plecotus they would not reveal how long this species has inhabited the cave. Humphrey and Kunz (1976) postulated that mild winters during the late Pleistocene allowed P. townsendii to roost in trees rather than caves and to avoid the present habit of long winter hibernation, whereas this bat now use caves as refugia to survive the intolerably cold post-Pleistocene winters. Humphrey and Kunz (1976) cited evidence that this bat is very sedentary and now survives only in isolated areas where suitable winter hibernacles are available. Handley (1959) stated that very few specimens of Plecotus townsendii have been reported considering its large geographic range. Durrant et al. (1955) said this species was thought to only inhabit the southern half of Utah until a few isolated citings were made in northern Utah caves, one of which (in Logan Canyon) contained the bat in large numbers. It is, therefore, very possible that P. townsendii has not inhabited Crystal Ball Cave, at least to the large degree that it does now, until Recent times.

Antrozous pallidus

Material--Anterior portion of left maxilla with C1/, P4/ (BYUVP 5365), anterior portion of fused dentary pair with left P/4, M/1 (BYUVP 5351), posterior portion of right dentary with M/2 (BYUVP 5333), posterior portion of left dentary with M/1 (BYUVP 5334). A posterior fragment of a left dentary (BYUVP 5350) and a right M/2 (BYUVP 5335) probably also belong to this taxon based on their large size and chiropteran affinities.

Discussion--This is the largest species of bat found in the assemblage and is easily distinguishable from other vespertilionids by its unique tooth formula of I1/2, C1/1, P1/2, M3/3, the configuration of the incisors and fenestra in the anterior palate, and the high coronoid process on the dentary. A. pallidus has not been reported living in the cave, but it presently occurs from the region of the cave southward into Mexico and along the west coast of the United States and southern British Columbia. A. bunkeri is now considered a subspecies of A. pallidus (Hall 1981). A. dubiaquercus occurs in Mexico and Central America and is distinguished from A. pallidus by normally having 3 lower incisors instead of 2. A. koopmani occurs only in Cuba. All the material listed above matches perfectly with modern A. pallidus which lives in the region of Crystal Ball Cave.

Order Lagomorpha
Family Ochotonidae
Ochotona princeps

Material--Anterior portion of skull with all teeth (BYUVP 5387), right maxilla with M/1,/2 (BYUVP 5407), right maxilla with M/2 (BYUVP 5406), right maxilla without teeth (BYUVP 5385), anterior portion of right maxilla with M/1 (BYUVP 5404), 2 anterior portions of right maxillae without teeth (BYUVP 5386, 5405), 4 partial right maxillae without teeth (BYUVP 5368, 5409, 5410, 5412), 6 left maxillae without teeth (BYUVP 5381, 5383, 5384, 5396, 5397, 5417), 3 anterior portions of left maxillae without teeth (BYUVP 5374-5376), 5 partial left maxillae without teeth (BYUVP 5369, 5382, 5408, 5415, 5416), right dentary with P/4, M/2,/3 (BYUVP 5399), right dentary with M/2,/3 (BYUVP 5393), right dentary with M/2 (BYUVP 5395), 5 right dentaries without teeth (BYUVP 5390-5392, 5401, 5419), partial right dentary with P/4 (BYUVP 5370), 4 partial right dentaries without teeth (BYUVP 5367, 5411, 5413, 5414), 2 anterior portions of right dentaries without teeth (BYUVP 5371, 5372), left dentary with P/4, M/1,/2 (BYUVP 5402), left dentary with M/1,/2 (BYUVP 5398), 3 left dentaries without teeth (BYUVP 5394, 5403, 5418), anterior portion of left dentary with P/4, M/1,/2,/3 (BYUVP 5388), posterior portion of left dentary with M/1,/2,/3 (BYUVP 5389), 2 posterior portions of left dentaries without teeth (BYUVP 5377, 5400), partial left dentary with M/1,/2 (BYUVP 5378), 3 partial left dentaries without teeth (BYUVP 5373, 5379, 5380).

Discussion--Ochotonids are easily distinguished from leporids by the lingual curve in the maxilla behind the cheek teeth, the presence of 5 upper cheek teeth rather than 6, and M/3 and its socket being anteroposteriorly short instead of triangular. O. princeps presently inhabits high elevations within 120 miles (190 km) of Crystal Ball Cave, both to the east and west (Hall 1981). The only other extant species, O. collaris, occurs only in northwestern Canada and Alaska (Hall 1981) and has been found in fossil deposits only in that region (Kurten and Anderson 1980). The only known extinct North American species of Ochotona is O. whartoni, which is known only from the early Pleistocene and is distinctly larger than the extant species (Kurten and Anderson 1980). All the specimens listed above are indistinguishable from Recent O. princeps.

Why O. princeps has been extirpated from the Snake Range is uncertain, but fossils have been recovered from Smith Creek Cave (Miller 1979) and many other Great Basin localities where this species does not live today. For example, Grayson (1977) recovered O. princeps dated at 7,000 to 12,000 Y.B.P. from the Fort Rock Basin of south-central Oregon. The area is now dominated by sagebrush, grasses, and sparse junipers, but modern pikas in the region only live where there is more succulant vegetation. Grayson (1977) attributed the disappearance of Ochotona to either a shift to more xeric habitat or to an eruption of Mt. Mazama 7,000 years ago. A similar extirpation in the Snake Range 315 miles (500 km) to the southeast supports the former of Grayson's hypotheses.

Family Leporidae
Sylvilagus idahoensis

Material--Right dentary with P/4, M/1,/2 (BYUVP 5534), right dentary without teeth (BYUVP 5444), right dentary fragment with P/3 (BYUVP 5584), left dentary with P/3,/4, M/1 (BYUVP 5536), left dentary fragment without teeth (BYUVP 5434).

Discussion--S. idahoensis is distinguished from all other leporids by its small size (see figure 4) and from Ochotona by the characters listed above. The P3/ of S. idahoensis does not widen posteriorly, as in other species of Sylvilagus, and the second reentrant angle is not crenulated as it is in many leporids. BYUVP 5536 is larger than any of the Recent S. idahoensis specimens to which it was compared (but smaller and distinct from other species of leporids), and the other specimens are also comparatively large, suggesting that this species may have decreased in size at the end of the Pleistocene. This species presently occurs in the region of the cave and to the north and west (Hall 1951, 1981).

Sylvilagus nuttallii

Material--Anterior portion of right dentary without teeth (BYUVP 5493), left dentary with M/1 (LACM 123658), anterior portion of left dentary with I/1, P/3,/4, M/1 (BYUVP 5578), four right P/3's (BYUVP 5717, 5731, 5769, and 5794), four left P/3's (BYUVP 5773, 5782, 5795, 5810).

Discussion--Sylvilagus is commonly distinguished from Lepus by its smaller size, although there is some overlap (namely, S. aquaticus and S. cunicularius are larger than L. americanus; J. A. White 1984 personal communication). The species of these genera presently living in the region are usually discernible by size, but the species within each genus are usually not (see figure 4).

Of the two species of Sylvilagus presently living in the Snake Range, S. audubonii has a larger mean size and tends to have much more crenulation in the second reentrant angle of P/3 than S. nuttallii (although there is overlap in both characters). S. floridanus, which occurs just south of Utah and Nevada, has an even larger mean size than S. audubonii but has little crenulation in the P/3 like S. nuttallii. BYUVP 5493 and LACM 123658 compare well in size with S. nuttallii and S. audubonii (see figure 4), but none of the nine P/3's of Sylvilagus size have much crenulation in the second reentrant angle of P/3, suggesting that they belong to S. nuttallii rather than S. audubonii. Although other species could be represented, the evidence suggests that at least the majority of the specimens listed above are of S. nuttallii.

S. nuttallii presently inhabits the region of the cave and northward, whereas S. audubonii inhabits the region of the cave and southward. S. nuttallii also tends to occur at higher elevations and in more wooded or bushy areas than S. audubonii, which lives in plains or open country (Hall 1951). Since Gandy Mountain is presently covered with only sparse bushes and is surrounded by open plains, the presence of S. nuttallii and absence of S. audubonii suggests the replacement of woodland-alpine vegetation by the present desert conditions since the Pleistocene.

Lepus cf. americanus

Material--Right dentary with I/1, P/3,/4, M/1,/2 (BYUVP 5519), anterior portion of left dentary with P/4, M/1 (BYUVP 5543). A left dentary with /I (BYUVP 5430) falls within the size range of L. americanus and L. californicus.

Discussion--The jaw dimensions and P/3 widths of these specimens are intermediate in size between the Sylvilagus specimens (described above) and the majority of the Lepus specimens (described below). They fall in and near the range of variation of the smallest L. californicus and largest S. audubonii specimens (see figure 4), but most of the P/3's of these two species have a highly crenulated second reentrant angle whereas the P/3 of BYUVP 5519 does not. These specimens are also indistinguishable from S. floridanus, but this species has never been reported living or as a fossil from Utah or Nevada.

L. americanus does not presently occur in the Snake Range but does occur 100 miles (160 km) to the north and east, mainly at high elevations (Durrant 1952, Hall 1951). Since the assemblage generally contains more species that presently range north of the cave than south of the cave, it is not at all unreasonable that L. americanus could have inhabited the region of the cave in the recent geologic past. Kurten and Anderson (1980) listed a number of fossil sites where L. americanus has been found south of its present range.

Lepus townsendii

Material--Fused dentary pair with right P/3,/4, M/1,/2,/3, left I/, P/3,/4, M/1,/2 (BYUVP 5488), right dentary with M/1,/2 (BYUVP 5467), right dentary with I (BYUVP 5533), left dentary with all teeth (BYUVP 5442), left dentary with I, P/3,/4, M/1,/2 (BYUVP 5484), 5 left dentaries without teeth (BYUVP 5424, 5429, 5474, 5532, LACM 123657), anterior portion of left dentary without teeth (BYUVP 5439), 7 isolated right P/3's (BYUVP 5733, 5770-5772, 5793, 5796, 5802), 7 isolated left P/3's (BYUVP 5735, 5736, 5780, 5783, 5790, 5791, 5804). A partial left dentary with P/3 (BYUVP 5485), 28 dentaries lacking P/3 (BYUVP 5422, 5427, 5436, 5438, 5448, 5450, 5454, 5456, 5458, 5462, 5473, 5475, 5478, 5483, 5487, 5489, 5493, 5495, 5500-5502, 5524, 5527, 5530, 5531, 5540-5542), 7 isolated right P/3's (BYUVP 5617, 5732, 5745, 5768, 5774, 5778, 5792), and 5 isolated left P/3's (BYUVP 5716, 5775, 5776, 5801, 5809) show characteristics common to both L. townsendii and L. californicus.

Discussion--L. townsendii and L. californicus are distinguished from Sylvilagus and L. americanus by their large size. They are distinguished from each other by L. townsendii having a larger mean size (see figure 4) and having less crenulation in the second reentrant angle of P/3 than L. californicus (Hibbard 1952). Miller (1976) observed L. californicus to have a highly crenulated P/3 in most, but not all, cases, and Hibbard (1944, 1963) noted that individual variation is very great. My observations and those of J. A. White (1984 personal communication) show that many individuals of these species cannot be distinguished by either size or the amount of crenulation in P/3. But statistical analysis can be used to estimate their relative abundance (Grayson 1977). Hibbard (1952) stated that the anterior part of P/3 is narrower in L. townsendii than in L. californicus, but although I noticed variation in the narrowness and roundedness of the anterior P/3's, it did not correlate with the amount of crenulation in the second reentrant angle of that tooth. BYUVP 5424, 5467, and 5474 have greater alveolar length (P/3-M/3) to diastema length ratios than any Recent leporid specimens measured (see figure 4), but they fall closest in size, especially based on their long tooth row length, to L. townsendii.

Since 11 of the 43 measurable Lepus dentaries are larger than any modern L. californicus specimens measured (see figure 4) and over half of the large Lepus P/3's from the assemblage show no crenulation (a very rare condition in L. californicus), it is clear that L. townsendii is well represented. Most of the 29 jaws that could be either L. townsendii or L. californicus are closer to the mean size of L. townsendii, and the isolated 13 P/3's of L. townsendii or L. californicus have slight crenulation in the second reentrant angle yet are considerably less crenulated than the vast majority of L. californicus specimens. Since only two highly crenulated P/3's clearly belonging to L. californicus (listed below) were found, most of these 13 P/3's with intermediate crenulation probably belong to L. townsendii. Based on this information I estimate that the ratio of L. townsendii to L. californicus specimens from the Crystal Ball Cave assemblage is about ten to one.

Grayson (1977) stated that L. townsendii is a more northern species and inhabits higher elevations and more grassy habitats than L. californicus, which prefers dryer shrubby areas. With Sylvilagus, the more northern species is represented in the assemblage while the more southern species is not. This is also the trend with Lepus. Hall (1981) reported L. townsendii in the area of Crystal Ball Cave but Durrant (1952), in a more detailed map, did not. Both report L. californicus throughout the Bonneville Basin area. I have seen numerous L. californicus around Gandy but never a L. townsendii, and J. C. Bates (1984 personal communication) reported never noticing any L. townsendii but numerous L. californicus. This difference between the fossil and living species at Gandy suggests that climatic boundaries have shifted upward in latitude and elevation since the Pleistocene. Grayson (1977), using both fossil and Recent data, demonstrated that L. californicus increased in number at the expense of L. townsendii during the Recent, and that it became the more dominant species in the Great Basin 5,000 to 7,000 years ago. Although the ecological and adaptational differences between these two species are not fully understood, Grayson (1977) attributed this change to a post-Pleistocene warming trend. The species shift indicated by the Crystal Ball Cave assemblage reiterates the data presented by Grayson (1977).

Lepus californicus

Material--Right P/3 (BYUVP 5781), left P/3 (BYUVP 5734). Twenty-nine dentaries and 13 other P/3's (listed under L. townsendii) show characters found in both L. townsendii and L. californicus. A left dentary with /I (BYUVP 5430) falls within the size range of L. americanus and L. californicus.

Discussion--L. californicus differs from L. townsendii in having a smaller mean size (see figure 4) and a more crenulated second reentrant angle in P/3 as discussed above. The two P/3 specimens listed above have more crenulation than was seen in eight Recent L. townsendii specimens but are typical of L. californicus. The 13 P/3's of either L. townsendii or L. californicus (listed and discussed above) show less crenulation than the vast majority of L. californicus specimens studied, but some of them could represent L. californicus since crenulation in the P/3 is not always present (Miller 1976). L. californicus is presently the most common lagomorph around Crystal Ball Cave (J. C. Bates 1983 personal communication), so its poor representation in the fossil assemblage suggests that it has only recently become abundant there.

Order Rodentia
Family Sciuridae
Marmota flaviventris

Material-Anterior portion of skull with right M1/,2/,3/, left M1/,3/ (BYUVP 6528), anterior portion of skull without teeth (LACM 123663), dentary pair with right M/1,/3 (BYUVP 6536), right dentary with P/4, M/1,/3 (LACM 123665), right dentary with M/1,/2,/3 (BYUVP 6543), right dentary with M/2,/3 (BYUVP 6621), right dentary with M/3 (BYUVP 6620), left dentary with /I, M/1,/2,/3 (BYUVP 6477), left dentary with M/1,/2,/3 (LACM 123669). Another 70 partial maxillae (some with teeth), 70 partial dentaries (some with teeth), and approximately 300 isolated cheek teeth (BYUVP 6476, 6478-6518, 6520-6527, 6529-6535, 6537-6542, 6544-6605, 6607-6619, 6622-6648, LACM 123664, 123666-123668, 123670) are of Marmota and compare favorably with M. flaviventris.

Discussion--Marmota is distinctly larger than other living sciurids (Hall 1981) but distinctly smaller than the extinct Paenemarmota (Repenning 1962). M. flaviventris is distinguished from M. monax by its anteriorly divergent upper tooth rows and from M. caligata, M. olympus, and M. vancouverensis by its smaller size (Hall 1981). M. flaviventris is also distinguished from these other species by its less massive dentition, M3/ being longer than wide, and M/3 having a triangular rather than a quadrangular outline (Logan 1983). Hay (1921) named M. arizonae based on a partial skull from northern Arizona and said it was similar to M. flaviventris. Since the specimen is probably late Pliocene in age and the validity of the species is uncertain (Kurten and Anderson 1980), it is not considered a candidate for the Crystal Ball Cave specimens, all of which are indistinguishable from Recent M. flaviventris.

The presence of M. flaviventris in the Crystal Ball Cave assemblage represents a shift in the climate and vegetation of the area because this species now inhabits only much higher elevations in the Snake Range (Hall 1981, Mead et al. 1982) and does not live on or around Gandy Mountain (J. C. Bates 1983 personal communication). Hall (1946) reported fossil M. flaviventris from several caves far south of this species' present range. Zimina and Gerasimov (1969) proposed that the marmot greatly expanded its distribution and numbers under late Pleistocene periglacial conditions for which it was well adapted but has since diminished significantly. M. flaviventris is not a cave-dwelling species, so its great abundance in the Crystal Ball Cave assemblage suggests that it once lived on Gandy Mountain in large numbers, strongly supporting the hypothesis of Zimina and Gerasimov (1969).

Spermophilus townsendii

Material--Anterior portion of skull with both I/'s (BYUVP 6060), partial skull with right P4/, M1/,2/ (BYUVP 6255), partial skull without teeth (BYUVP 6462), 7 right dentaries with all teeth (BYUVP 6107, 6109, 6141, 6282, 6284, 6326, 7256), and 2 left dentaries with all teeth (BYUVP 6421, 6433). Another 439 partial maxillae (some with teeth), 562 partial dentaries (some with teeth), and approximately 4,000 isolated teeth compare favorably with S. townsendii.

Discussion--Spermophilus townsendii has the smallest mean size of any North American species of Spermophilus and is also slightly smaller than Ammospermophilus leucurus (Hall 1981). Spermophilus also differs from Ammospermophilus by having distinctly larger masseteric tubercles just anterior to the upper tooth rows (Hall 1981). The three partial skulls listed above and many of the partial maxillae without teeth have large masseteric tubercles that distinguish them from Ammospermophilus. All of the specimens listed above compare best in size with S. townsendii, but some of those only referred to this species are probably Ammospermophilus. Kurten and Anderson (1980) listed 13 extinct species of Spermophilus, but the only one close enough in size and age of deposits to the Crystal Ball Cave specimens to be considered is S. taylori, named by Hay (1921) based on a single specimen from Texas. Kurten and Anderson (1980) consider this a doubtful species, and it is most likely a synonym of S. townsendii, so it is not considered here.

The presence of a single species of Spermophilus at Crystal Ball Cave is a striking contrast to the five possible species recovered from Smith Creek Cave in subequal numbers (Mead et al. 1982). These include S. cf. townsendii, S. variegatus, and S. cf. lateralis, which still inhabit the Snake Range, and S. cf. richardsonii and S. cf. beldingi, which have been extirpated but still inhabit Utah and/or Nevada (Hall 1981). The reason for this difference may be that Smith Creek Cave is at the base of 12,050 foot (3,673 meter) Mount Moriah and at the edge of the flat open Snake Valley, an area of diverse niches in contact with several diverse environments even now, and certainly an area across which climatic boundaries crossed many times during the Pleistocene. Gandy Mountain, on the other hand, is only a small hill far out in Snake Valley, the area most favorable to S. townsendii (Hall 1946), and is isolated from the main Snake Range by 6 miles (10 km) of flat valley.

The abundance of Spermophilus townsendii fossils at Crystal Ball Cave suggests that this squirrel lived around Gandy Mountain in large numbers for a long time, probably since fossils started accumulating in the cave. Durrant (1952) said this species is well-suited to the western Utah desert and is particularly abundant around springs. Hall (1946) told how S. townsendii was a traditional food for native American Indians. S. townsendii is not a cave-dwelling animal as is Neotoma, and yet it is over twice as abundant as Neotoma in the assemblage (contrary to my earlier statement that Neotoma was the best represented genus, Heaton 1984). Neotoma has a much more restricted niche than Spermophilus and is never found in large numbers. Since squirrels are very unlikely to venture deep into caves, all the specimens must have been brought in by wood rats and/or small carnivores. It is interesting that fossil deposition occurred so rapidly, even deep in this isolated cave, that an outside species is better represented than the primary cave-dwelling species. J. C. Bates (1984 personal communication) reported seeing no squirrels on Gandy Mountain and only a few in the surrounding valley in the many years he has lived in Gandy. This, in contrast to its abundance as a fossil, suggests that S. townsendii reduced its numbers at the close of the Pleistocene.

Ammospermophilus cf. leucurus

Material--Right maxilla without teeth (BYUVP 8295), 2 left maxillae without teeth (BYUVP 8296, 8297). Some of the 439 maxillae, 562 dentaries, and approximately 4,000 isolated teeth listed under Spermophilus townsendii probably also belong to this taxon.

Discussion--Ammospermophilus is distinguished from Spermophilus by its smaller masseteric tubercle and its less robust lower cheek teeth (Hall 1981). A. leucurus now lives around Gandy Mountain while A. harrisii, A. interpres, A. insularis, and A. nelsoni, the other four extant species, occur only south of Utah (Hall 1981), so the Crystal Ball Cave specimens are referred to A. leucurus although no character could be found to rule the others out.

According to Durrant (1952) A. leucurus commonly occurs with S. townsendii but has a more restricted habitat, preferring rocky terrains. Ammospermophilus is best adapted for high temperatures (Vaughan 1972), and its low abundance in the assemblage compared to Spermophilus townsendii suggests that it has not inhabited the area as long, at least not in its present abundance. With summers becoming hotter and drier at the close of the Pleistocene, Ammospermophilus may have increased its numbers at the expense of other species in Recent times.

Eutamius minimus
Material--Right dentary with P/4, M/1,/2 (BYUVP 6812), 3 right

dentaries with P/4, M/1 (BYUVP 6171, 6210, 6755), left dentary with all teeth (BYUVP 6190).

Discussion--Eutamius has two premolars in each maxilla whereas Tamius has only one. E. minimus is the smallest species of Eutamius and has a narrower and squarer P/4 than E. dorsalis or E. umbrinus. All the specimens listed above match E. minimus with respect to the P/4 and are smaller than the other species. E. minimus and E. dorsalis live in the region of Crystal Ball Cave and E. umbrinus lives higher in the Snake Range and westward into Nevada (Hall 1981). E. minimus was also recovered from Smith Creek Cave (Mead et al. 1982). E. minimus inhabits diverse habitats from deserts to forests, so its presence in the assemblage is not surprising.

Eutamius dorsalis

Material--Right dentary with P/4, M/1,/2,/3 (BYUVP 6233), right dentary with P/4, M/1 (BYUVP 6257), 2 right dentaries with M/1 (BYUVP 5974, 6304), 2 left dentaries with M/1 (BYUVP 6129, 6134). Three partial right maxillae with M1/ (BYUVP 6064, 6288, 6295) and a partial left maxilla with M1/ (BYUVP 6000) also compare favorably with this species.

Discussion--E. dorsalis is distinctly larger than E. minimus and slightly larger than E. umbrinus (Mead et al. 1982). It has a distinct isolated mesoconid on M/1 that is lacking in E. umbrinus and is part of an ectolophid in E. minimus (Miller 1976). The M/1's of the six dentaries listed above match E. dorsalis in this character, and the four maxillae listed above match best in size with E. dorsalis but cannot be positively distinguished from E. umbrinus. Of the larger chipmunks, only E. cf. umbrinus was reported from Smith Creek Cave (Mead et al. 1982), and I have found only E. dorsalis in Crystal Ball Cave. Their present ranges may account for this difference since E. umbrinus only inhabits the Snake Range west of Crystal Ball Cave while E. dorsalis inhabits the entire range (Hall 1981). Their ranges show that E. umbrinus is more isolated in areas of high elevation and more commonly absent from the areas once covered by Lake Bonneville.

Family Geomyidae
Thomomys umbrinus

Material--Anterior portion of skull with both I/'s (BYUVP 6656), anterior portion of skull with left I/ (LACM 123672), right dentary with /I, P/4, M/1 (BYUVP 6657), left dentary with P/4 (BYUVP 8283). Four palates without teeth (BYUVP 6653-6654, 6664-6665), 4 right dentaries without cheek teeth (BYUVP 6660, 6663, 6666, 8281), and 8 left dentaries without cheek teeth (BYUVP 6655, 6658-6659, 6662, 6681, 7009-7010, 8282) also compare favorably with this species.

Discussion--Thomomys is distinguished from other North American geomyids by the absence of a superficial groove on the anterior face of the upper incisors (illustrations in Hall 1981), and none of the I/'s listed above have this groove. T. umbrinus differs from T. talpoides and T. monticola, the only other species of Thomomys living in Nevada, Utah, or surrounding areas, by having a sphenoidal fissure, by not having the palatine foramina fully anterior to the anterior openings of the infraorbital canals (Durrant 1952), and by the absence of a lingual indentation in the anterior lobe of P/4 (Hall 1946). The two Thomomys skulls from Crystal Ball Cave have the sphenoidal fissure, and their palatine foramina are fully anterior to the infraorbital canals. The two P/4's also lack the lingual indentation as in T. umbrinus. My observations and also figures 308-321 in Hall (1946) indicate that T. umbrinus has a larger mean size than the other two species mentioned (contrary to Bergman's rule), and all the Crystal Ball Cave specimens compare best in size with the larger T. umbrinus.

T. umbrinus is the only geomyid currently inhabiting the Snake Range, and it is a southern species extending from Nevada and Utah southward into Mexico (Hall 1981). T. bottae and T. townsendii are now considered as subspecies of T. umbrinus (Hall 1981). T. talpoides, which inhabits mountain ranges to the east and west of the Snake Range, has Nevada and Utah as almost its southern boundary and extends northward into Canada. T. talpoides tends to inhabit higher elevations than T. umbrinus as well as higher latitudes. T. cf. talpoides is the only geomyid reported from Smith Creek Cave (Goodrich 1965).

Hall (1946) pointed out that although T. umbrinus is usually a lower elevation species than T. talpoides, T. umbrinus is the only geomyid in the Snake Range and occurs at all elevations (but is less abundant at higher elevations than T. talpoides is at similar elevations in other ranges). Hall (1946) attributed this to antiquity of occupancy and proposed that T. umbrinus, having no competitors in the Snake Range, developed populations adapted to higher elevations. Since T. umbrinus was the species best adapted to the valleys surrounding the Snake Range, no species which were better adapted to higher elevations could pass through to their favorable habitat. This could explain why the Crystal Ball Cave assemblage suggests no northward range shift for species of Thomomys as it does for other groups such as lagomorphs. If Hall (1946) is right, the tentative assignment of the Smith Creek Cave specimen to T. talpoides (Goodrich 1965) must be in error. Another possibility is that predatory birds transported the specimen to the cave, but this seems unlikely since T. talpoides occurs only as close as 45 miles (75 km) to the northwest and 108 miles (180 km) to the east of Smith Creek Cave. Hall (1946) also pointed out that geomyids, as individuals, are extremely sedentary, and this could be the cause of their slow invasion and northward retreat compared to other mammals.

Family Heteromyidae
Perognathus cf. formosus

Material--Partial right maxilla with P4/ (BYUVP 6682), 2 right dentaries with P/4 (BYUVP 6859, 6879), 2 right dentaries with M/2 (BYUVP 6711, 6856), left dentary with all teeth (BYUVP 6697), left dentary with P/4, M/1 (BYUVP 6786), left dentary with P/4, M/2 (BYUVP 6115).

Discussion--P. longimembris, P. parvus, and P. formosus now inhabit the Crystal Ball Cave area, and the closest other species range more than 150 miles (250 km) to the east and south (Hall 1981). Of the three local species, P. longimembris can be ruled out because its M/3 is distinctly smaller than its P/4 (Hall 1981), and BYUVP 6697 has the opposite condition. P. parvus and P. formosus are very similar dentally, and the Crystal Ball Cave specimens match well with both of them. P. formosus has a larger mean size than P. parvus, and the Crystal Ball Cave specimens compare best in size with P. formosus although P. parvus and several other western species cannot be ruled out. Miller (1979) referred all the Perognathus specimens found at Smith Creek Cave to P. cf. parvus, but since the identification was tentative at both caves, it does not seem wise to speculate about a possible difference between the two assemblages.

Microdipodops megacephalus

Material--Right maxilla with P4/, M1/,2/ (BYUVP 6695), right maxilla with P4/, M2/ (BYUVP 6781), right maxilla with M1/ (BYUVP 6709). Three partial right maxillae with P4/ (BYUVP 6669, 6674, 6797), a partial right maxilla with a partial M1/ (BYUVP 6759), a right dentary with /I, P/4, M/1 (BYUVP 6693), 2 right dentaries with P/4 (BYUVP 6795, 6860), and a left dentary with P/4 (BYUVP 6708) are of Microdipodops and compare favorably with M. megacephalus.

Discussion--Microdipodops is most similar to Perognathus but can be distinguished dentally by the molars having a single enamel loop as opposed to the biloph nature of Perognathus molars. The P/4's are also distinct in being more hypsodont and having a straight posterolabial border as opposed to the round and symmetrical nature of the Perognathus P/4's. M. megacephalus ranges throughout most of Nevada and into neighboring states including Utah, and it is currently found around Crystal Ball Cave (Hall 1981). M. pallidus, the only other species, occurs along the southern Nevada-California border more than 200 miles (320 km) southwest of Crystal Ball Cave (Hall 1981). M. megacephalus can be distinguished from M. pallidus by the latter possessing a small notch in the labial side of M1/, and all the Crystal Ball Cave specimens possessing the M1/ are clearly M. megacephalus. M. cf. megacephalus was reported at Smith Creek Cave (Miller 1979), and all heteromyid taxa recovered were low in abundance as at Crystal Ball Cave. This low abundance is probably due to a low density in life since even now they are rarely seen in the area.

Dipodomys microps

Material--Two right dentaries with /I (BYUVP 6672 and 8284), left dentary fragment with P/4 (BYUVP 6676). Nine maxillae without teeth (BYUVP 5593, 6667-6668, 6670, 6675, 6677-6680) and 2 right dentaries without teeth (BYUVP 6673, 6683) also compare favorably with this taxon.

Discussion--Dipodomys is distinctly larger than other heteromyid genera. D. microps is distinguished from other species of Dipodomys by having chisel-shaped lower incisors (anterior face flat) rather than awl-shaped lower incisors (anterior surface round), and the incisors of BYUVP 6672 and 8284 are chisel-shaped. P/4 is also distinct in having a larger and more isolated anterior loph than D. ordii or D. merriami but not a complete separation of lophs as in D. deserti, and the P/4 of BYUVP 6676 clearly matches D. microps. The referred specimens also match perfectly with Recent D. microps, but lack the diagnostic teeth. Of the four species of Dipodomys presently living in Utah and Nevada, D. microps and D. ordii are found in the Snake Range while D. merriami and D. deserti occur more than 125 miles (200 km) to the south and west (Hall 1981). D. microps has a much smaller range than D. ordii, occurring only in Nevada and parts of surrounding states (Hall 1981). The Dipodomys specimens recovered from Smith Creek Cave (Miller 1979) were referred to D. ordii because they had awl-shaped lower incisors. This difference between the two assemblages is difficult to explain because the range differences between these species do not suggest distinct differences in habitat preference.

Family Cricetidae
Peromyscus maniculatus

Material--Right maxilla fragment with M1/,2/ (BYUVP 6703), left maxilla with M1/,2/,3/ (BYUVP 6782), left maxilla fragment with M1/,2/ (BYUVP 6771). Thirty nine Peromyscus dentaries containing one or more molars compare favorably with P. maniculatus and P. crinitus.

Discussion--Of the six species of Peromyscus that inhabit Utah and Nevada, only P. maniculatus, P. truei, and P. crinitus currently live around Crystal Ball Cave (Hall 1981). P. maniculatus was captured live inside the cave by the author in 1982 and 1983. Peromyscus fossils from Smith Creek Cave were not identified to the species level (Goodrich 1965, Mead et al. 1982, Miller 1979). Dental characters which distinguish species of Peromyscus are few and not always reliable. P. maniculatus and P. truei belong to the subgenus Peromyscus, which has accessory tubercles or enamel loops on the labial side of M1/ and M2/; P. crinitus belongs to the subgenus Haplomyomys which lacks these features (Hall 1981). I found this character to be quite reliable, and the specimens listed above all have prominent cusps on M1/ and M2/. In further refinement of this character, Miller (1971, 1976) was able to separate P. maniculatus from all other western species of Peromyscus by the presence of an anteroconule on M1/ with direct attachment to the anterocone rather than being joined to it by a distinct loph as in P. truei. Specimens listed above fit P. maniculatus in this respect. Species of the subgenus Haplomyomys usually lack the anteroconule entirely (Hall 1981, Miller 1971, 1976). Unfortunately, excessive wear on the teeth erases this character.

Of the 40 Peromyscus dentaries containing one or more molars, 39 compare best in size with the smaller P. maniculatus and P. crinitus, but no character could be found to separate these species based on dentaries. Miller (1976) found the P/3's of P. maniculatus, P. crinitus, and P. eremicus to be relatively more reduced than P. boylii and P. truei. The 8 Crystal Ball Cave Peromyscus dentaries containing M/3 tend to have M/3 relatively reduced as in P. maniculatus, P. crinitus, and P. eremicus, and in size all the 39 dentaries listed above compare best in size with the smaller P. maniculatus and P. crinitus.

Peromyscus cf. crinitus

Material--Right maxilla with M1/,2/ (BYUVP 6780), left maxilla with M1/,2/ (BYUVP 6769), left maxilla with M1/ (BYUVP 6715). Thirty nine Peromyscus dentaries containing one or more molars compare favorably with P. maniculatus and P. crinitus.

Discussion--These specimens lack accessory tubercles and enamel loops on the 2 principle outer angles of M1/ and M2/, so they probably belong to the subgenus Haplomyomys (Hall 1981). Of the two species of Haplomyomys found in Utah, P. crinitus and P. eremicus, the Crystal Ball Cave specimens compare better in size with the smaller P. crinitus (although there is considerable overlap). Some of the 39 dentaries discussed under P. maniculatus (above) could also belong to this species since no character was found to distinguish them based on dentaries. P. crinitus is presently found around the cave while P. eremicus only ranges as close as 135 miles (225 km) to the south (Hall 1981), and this further suggests that these specimens are P. crinitus.

Peromyscus cf. truei

Material--Left dentary with M/1 (BYUVP 6718).

Discussion--P. truei is the largest species of Peromyscus living in Utah and Nevada (Durrant 1952, Hall 1981), and the M/1 listed above compares well in size with this species and is larger than the mean size of P. eremicus and P. boylii and distinctly larger than any P. maniculatus or P. crinitus M/1's examined. Identification is based only on size since no other character could be found to distinguish M/1's of Peromyscus. This species is found throughout the Great Basin, so its presence in the assemblage is not surprising.

Neotoma lepida

Material--Partial skull without teeth (LACM 123671), 2 partial right maxillae with M1/ (BYUVP 7045, 7065), 2 left maxillae with M1/ (BYUVP 7154), partial left maxilla with M1/ (BYUVP 7246).

Discussion--N. lepida and N. cinerea are the only species of Neotoma that presently inhabit the Snake Range (Hall 1946, 1981). Of three wood rats that I trapped in Crystal Ball Cave and two elsewhere on Gandy Mountain in 1982 and 1983, all were N. lepida. I did trap a N. cinerea in another cave in the Snake Range 22 miles (35 km) south of Crystal Ball Cave, so they are known to inhabit caves in the area. Miller (1979) reported both N. lepida and N. cinerea from Smith Creek Cave but did not comment on their relative abundance. Of these two species, N. cinerea is much more boreal than N. lepida, having a more northern range and being found at higher elevations (Finley 1958, Hall 1946, 1981). Durrant (1952) and Hall (1981) also reported N. albigula, N. mexicana, and N. stephensi living in Utah but far south and east of Crystal Ball Cave.

Neotoma cinerea is usually distinguishable from N. lepida by its larger size and deeper anterolabial reentrant angle on M1/ (Finley 1958). According to Hall (1946), the maxillary alveolar length is always 8.8 mm or less in N. lepida and 9.1 mm or more in N. cinerea for the Nevada subspecies, and Finley (1958) reported only a slight overlap for the Colorado subspecies. The three other Utah species of Neotoma are intermediate in size between N. lepida and N. cinerea, and N. albigula has the M1/ pattern of N. lepida while N. mexicana and N. stephensi have the M1/ pattern of N. cinerea (Finley 1958). Because these are the most diagnostic characters, only maxillae with M1/ and/or a measurable alveolar length were considered.

The Crystal Ball Cave specimens listed above compare best in size with N. lepida, the only species of Neotoma known to presently inhabit the cave. Maxillary alveolar lengths of Neotoma specimens from the cave show a strongly bimodal distribution, suggesting that N. albigula, N. mexicana, and N. stephensi are not represented since they are intermediate in size between N. lepida and N. cinerea. The shallow anterolabial reentrant angle of the M1/'s also compares favorably with N. lepida. The scarcity of N. lepida specimens in the assemblage suggests that this species probably has not always inhabited the cave as it does now.

Neotoma cinerea

Material--Anterior portion of skull with both I/, M1/,2/ (BYUVP 7384), maxilla pair with all teeth except left I/ (BYUVP 7281), maxilla pair with right M1/,2/,3/, left M1/,2/ (BYUVP 7282), maxilla pair with both M1/,2/ (BYUVP 7067), maxilla pair with right M/1,/2 (BYUVP 7015), maxilla pair with left M/1 (BYUVP 7213), 9 right maxillae with M1/,2/,3/ (BYUVP 7136, 7149, 7158, 7167, 7214, 7248, 7254, 7314, 7320), 3 right maxillae with M1/ (BYUVP 7273, 7316, 7330), 25 partial right maxillae with M1/ (BYUVP 7014, 7018, 7024, 7038, 7046, 7104, 7114, 7125, 7134, 7138, 7147, 7170, 7177, 7180, 7182, 7197, 7204, 7216, 7242, 7247, 7249, 7276, 7344, 7348, 7349), 10 right maxillae without teeth (BYUVP 7255, 7343, 7353, 7367, 7377, 8286-8290), 7 left maxillae with M1/,2/,3/ (BYUVP 7095, 7212, 7250, 7257, 7274, 7376, 7379), 4 partial left maxillae with M1/,2/ (BYUVP 7101, 7174, 7179, 7324), partial left maxilla with M1/,2/ (BYUVP 7017), 34 partial left maxillae with M1/ (BYUVP 7021, 7061, 7062, 7072, 7073, 7087, 7099, 7106, 7133, 7140, 7142, 7144, 7145, 7151, 7162-7164, 7172, 7175, 7183, 7189, 7200, 7205, 7217, 7220, 7225, 7267, 7300, 7317, 7318, 7322, 7351, 7362, 7371), 6 left maxillae without teeth (BYUVP 7171, 7346, 8291-8294). Another approximately 200 maxillae, 200 dentaries, and 2,000 isolated molars compare best with this species.

Discussion--Neotoma cinerea is recognized by its large size and deep anterolabial reentrant angle on M1/ as discussed above. N. cinerea has the largest mean size of any species of Neotoma, and all the specimens listed above match Recent N. cinerea in size and have he deep anterolabial reentrant angle on M1/ when this tooth is present. This makes N. cinerea the second best represented species in the Crystal Ball Cave assemblage after Spermophilus townsendii. The fact that N. cinerea is abundant in the assemblage, but not found in the cave now, while N. lepida is rare in the assemblage, but now the only wood rat living in the cave, suggests that a replacement of N. cinerea by N. lepida has recently taken place in the area. The great abundance of N. cinerea remains at Sites 1 and 2 of Crystal Ball Cave also helps substantiate my hypothesis that wood rats were the primary means of transporting fossils, especially of large mammals, into the cave. The dominance of N. cinerea over N. lepida in the assemblage suggests that N. cinerea was the primary species involved in this transport.

The ecological differences between N. cinerea and N. lepida have significance both to the replacement of the former species by the latter and to the accumulation of fossils in the cave. Finley (1958), in his detailed study of Colorado wood rats, found den sites to be the most limited resource for all species. Since all wood rats prefer the same basic types of den sites, namely rocky crags and caves, multiple species are rarely found coexisting (Finley 1958). This suggests that when conditions at Crystal Ball Cave reached a threshold where they favored N. lepida over N. cinerea, the replacement took place quickly. N. cinerea prefers higher elevations and latitudes than N. lepida, and hot summers in arid regions seem to be a limiting factor for this species (Finley 1958, Hall 1981). The changing conditions that led to the replacement of N. cinerea by N. lepida may have been the increase in temperature and decrease in moisture at the close of the Pleistocene, the shift in vegetation caused by it, or both. Regarding food, Finley (1958) stated that N. cinerea prefers soft-leaved shrubs, forbs, and montane conifers, whereas N. lepida prefers xerophytic shrubs, forbs, cacti, and shrubby trees.

Species of Neotoma differ somewhat in den preferences and collecting habits. Finley (1958) stated: "Dens of N. cinerea are usually in high vertical crevices in cliffs or caves, whereas those of . . . N. lepida are usually in low horizontal crevices or under boulders or large fallen blocks. Dens of [N.] cinerea usually contain larger accumulations of sticks and bones." That N. cinerea collects more material, especially bone, is very significant since I consider wood rats as the primary mechanism of fossil deposition at Crystal Ball Cave. This suggests that the rate of bone deposition decreased when N. lepida replaced N. cinerea, and it helps explain why many elements of the present local fauna are so poorly represented and why all the dated fossils were late Pleistocene rather than Recent in age.

A replacement of N. cinerea by N. lepida parallels the replacement of Sylvilagus nuttallii by S. audubonii and Lepus townsendii by L. californicus (discussed above) and helps confirm that a warming trend took place in the recent past. Although N. cinerea still lives in the area, it seems to have been driven to higher elevations in the Snake Range.

Ondatra zibethicus

Material--Palate without teeth (BYUVP 7383), partial right dentary with anterior 2/3 of M/1 (BYUVP 7391).

Discussion--Ondatra is easily distinguished from other microtine rodents by its large size combined with rooted molars. O. zibethicus is now considered the only extant species of Ondatra (Hall 1981), and the Crystal Ball Cave specimens are indistinguishable from this species. A number of fossil species have been named, but there is considerable confusion about their status (Miller 1976). All the extinct species considered valid by Semken (1966) and Nelson and Semken (1970) are smaller than O. zibethicus. The Crystal Ball Cave dentary is almost as large as the largest O. zibethicus to which it was compared. The M/1 is 7.9 mm long and 2.5 mm wide which best matches measurements taken from Wisconsinan-age O. zibethicus specimens (Nelson and Semken 1970). The palate is slightly smaller than the mean of O. zibethicus but well within its range of variation.

O. zibethicus is not presently found around Gandy but occurs as close as 100 miles (170 km) to the north, east, and south (Hall 1981). Since Ondatra is a reliable indicator of permanent water (Nelson and Semken 1970), the retreat of Lake Bonneville and loss of perennial streams in the area probably lead to its extirpation from the Snake Range.

Microtus cf. longicaudus

Material--Two left M3/'s (BYUVP 6940 and 6981), 7 right M/3's (BYUVP 8220-8226), 15 left M/3's (BYUVP 7002, 8227-8241). Numerous other partial jaws and isolated molars cannot be distinguished from Lagurus but lack characters that would assign them to other species of Microtus, some of which are likely Microtus since over a third of the microtine M/3's belong to Microtus. Among these are a partial skull with both M1/,2/ and the posterior incisive foramina (BYUVP 8285) and a right maxilla with M1/,2/ (BYUVP 6943).

Discussion--Microtus differs from Lagurus, the only other microtine of its size with rootless molars, in having 3 transverse loops on M/3 rather than 4 prisms, some of which are closed triangles, and in having a large semicircular posterior loop on M3/ rather than a simple elongate loop (Hall 1981). The 2 M3/'s and 22 M/3's from Crystal Ball Cave listed above clearly match Microtus in this respect. There are many species of Microtus, some of which have distinct dental characteristics and some of which do not.

The only two species of Microtus now inhabiting the Snake Range are M. longicaudus and M. montanus, and no character could be found to distinguish them dentally. The incisive foramina of M. longicaudus are not constricted posteriorly as are those of M. montanus, but they differ from those of Lagurus only in having slightly curved rather than straight external margins. Since only the posterior end of the incisive foramina are found on skulls that could be Microtus from Crystal Ball Cave, skulls of M. longicaudus in the collection are indistinguishable from Lagurus. Of 13 skulls containing incisive foramina which may be Microtus, 2 have constricted incisive foramina as in M. montanus (listed below), and 11 compare well with M. longicaudus and Lagurus.

Three other species of Microtus presently occur in Utah but not in the Snake Range: M. pennsylvanicus and M. richardsonii in the central mountain ranges and M. mexicanus in the southwestern corner of the state. M. pennsylvanicus has a posterior loop on M2/ not found in other species, and this character was only found on one specimen (listed below). M. richardsonii is distinctly larger than the other species described here, and none of the microtine specimens from Crystal Ball Cave are large enough to compare with it. M. mexicanus is dentally indistinguishable from M. montanus and M. longicaudus, and its incisive foramina are identical to Lagurus and similar to M. longicaudus.

The specimens listed above are identical to Recent specimens of M. longicaudus, M. mexicanus, and more distant ranging species. But since M. longicaudus presently occurs at Crystal Ball Cave, while M. mexicanus occurs more than 250 miles (400 km) to the southeast (Hall 1981), and because the general trend in the region is for range boundaries to be migrating northward, the Crystal Ball Cave specimens (except the few discussed below) are referred to M. longicaudus.

Microtus cf. montanus

Material--Two partial palates without teeth which include the posterior end of the incisive foramina (BYUVP 8218, 8219).

Discussion--M. montanus is the only microtine of its size presently occurring in Utah or Nevada with incisive foramina that abruptly constrict posteriorly and are narrower posteriorly than anteriorly. The posterior ends of the incisive foramina in these two specimens are too narrow to be M. longicaudus, M. pennsylvanicus, M. mexicanus, or Lagurus curtatus. M. townsendii and M. oregoni also have incisive foramina like M. montanus, but they both occur only along the pacific coast from northern California to southern British Columbia. Since M. montanus presently occurs in the Snake Range (Hall 1981), the Crystal Ball Cave specimens are referred to it. M. montanus tends to occur at higher elevations than other species of Microtus in Utah (Durrant 1952), so its presence in the assemblage suggests that conditions at the cave during the Late Pleistocene may have been like those of higher elevations in the Snake Range now.

Microtus cf. pennsylvanicus

Material--Partial skull with right M1/,2/ (BYUVP 6973).

Discussion--M. pennsylvanicus is unique in having a rounded posterior loop behind the 4 closed angular sections of M2/. This single specimen from the assemblage has this posterior loop, but the loop is not completely closed off from the preceding triangle as in the Recent specimens to which it was compared. Since the distinguishing character is not fully developed, the specimen is only referred to M. pennsylvanicus. This species is not presently found in the Snake Range, but it occurs 114 miles (190 km) east of Crystal Ball Cave in the mountains of central Utah and is a northern species (Hall 1981). Considering the climatic shifts since the recession of Lake Bonneville, it is not unlikely that it could have inhabited the Snake Range during the Late Pleistocene.

Lagurus curtatus

Material--Skull with right I/, M2/,3/, left I/, M1/,2/ (BYUVP 6899), left dentary with M/1,/2,/3 (BYUVP 6977), left dentary with M/2,/3 (BYUVP 6986), 28 right M/3's (BYUVP 8242-8270), 9 left M/3's (BYUVP 8271-8280). Numerous partial jaws and isolated molars may be L. curtatus but cannot be distinguished from Microtus longicaudus (as discussed above).

Discussion--The differences between Lagurus and Microtus are discussed above. L. curtatus, the only North American species of Lagurus, is distinguished from Old World representatives by having 4 instead of 5 closed triangles on M/3 and cement present in the reentrant angles of the molars (Hall 1981). This species presently occurs in the Snake Range and northward into Canada (Hall 1981). Lagurus specimens are nearly twice as abundant as those of Microtus in the assemblage, but since no information on their Recent relative abundance or habitat differences could be found, it is difficult to know the reason for this.

Order Carnivora
Family Canidae
Canis cf. latrans

Material--Lower incisor (BYUVP 7459), right C/1 (LACM 123675), partial left M/1 (BYUVP 7460). The frontal region of a skull (LACM 123676) and an anterior fragment of a left dentary without teeth (BYUVP 7458) also compare favorably with this species.

Discussion--These specimens are indistinguishable from specimens of Recent C. latrans, generally recognized as the only species of coyote in the Pleistocene or Recent (Giles 1960). Dentally, C. latrans falls within the wide range of variation of the domestic dog, C. familiaris (Anderson 1968), so the possibility that the Crystal Ball Cave specimens are C. familiaris cannot be totally eliminated. But C. latrans is presently very abundant around the cave (J. C. Bates 1983 personal communication, Hall 1981) and has been recognized from nearby Pleistocene assemblages that have better stratigraphic control (Kurten and Anderson 1972, Miller 1979), so there is no reason to believe it would not be found in the assemblage. Also, domestic dogs tend to have many more tooth malformations than coyotes (Anderson 1968) and none are seen in the Crystal Ball Cave specimens. Lack of human fossils and artifacts at Crystal Ball cave makes domestic dogs less likely to be present than at sites that contain such remnants of human occupation. Although residents of Gandy have domestic dogs that sometimes roam on Gandy Mountain, the lack of any canid specimens in the assemblage that cannot be referred to native species also supports the conclusion that the Crystal Ball Cave specimens are C. latrans.

Canis cf. lupus
Material--Partial right M1/ (BYUVP 7455), left P/1 (BYUVP 7457),

posterior end of right M/1 (BYUVP 7456), left M/1 (LACM 123674), axis (LACM 123710).

Discussion--Identification of these canid fossils is based on their size, being substantially larger than C. latrans but considerably less robust than C. dirus. They do, however, fit within the large size range of C. familiaris, so the identification must be tentative. Goodrich (1965) reported C. lupus from Smith Creek Cave but did not describe the material. C. lupus has been reported living in the Snake Range in Recent times (Hall 1981) although Man has now reduced its range and numbers considerably.

Vulpes vulpes

Material--Skull with right P1/,2/,4/, left P4/, M2/ (BYUVP 8299), posterior portion of right maxilla with M1/,2/ (BYUVP 7466), partial left maxilla with M1/,2/ (BYUVP 7467), two right C1/'s (BYUVP 7468, 7470), left C1/ (BYUVP 7469), right P4/ (BYUVP 7474), left P4/ (BYUVP 7471), right dentary with M/2 (BYUVP 7461), posterior portion of right dentary with P/4, M/1,/2 (BYUVP 7463), left dentary with M/1,/2 (BYUVP 7464), anterior portion of left dentary with M/1,/2 (BYUVP 7462), right P/4 (BYUVP 7475), left P/4 (BYUVP 7472). An anterior fragment of a right dentary without teeth (BYUVP 7465) and an anterior fragment of a left dentary without teeth (BYUVP 7476) also compare favorably with this species.

Discussion--Vulpes is distinguished from Urocyon by the configuration of the crest on top of the skull and the lack of a prominent "step" on the posteroventral margin of the dentary. The ventral margin of the dentary of Vulpes curves upward posteriorly beginning at the posterior end of the tooth row while in Urocyon it remains uncurved well behind the tooth row all the way to the "step." Urocyon, which ranges from the cave site southward and throughout North America, is intermediate in size between V. vulpes and V. velox. Four of the Crystal Ball Cave specimens include the posterior dentary and lack the "step" characteristic of Urocyon, and all the Crystal Ball Cave specimens are larger than the largest Urocyon specimen examined but compare well in size and shape to V. vulpes.

V. vulpes does not presently occur around Crystal Ball Cave but V. velox and U. cinereoargenteus do (J. C. Bates 1983 personal communication, Hall 1981). The presence of the more northern V. vulpes but not the more southern U. cinereoargenteus in the cave assemblage represents a northward shift of the boundary between these two species. The ranges of V. vulpes and U. cinereoargenteus do overlap to a degree now, but in the western United States the overlap is not great, and where it does occur V. vulpes favors the higher elevations and U. cinereoargenteus the lower elevations (Hall 1981). Based on range maps in Hall (1981), the range of V. vulpes in the western United States is quite scattered, suggesting that it is relectual and that this species is diminishing in numbers there. U. cinereoargenteus has a distinct northern boundary across Utah and Nevada with no remnant populations, suggesting that this species has been making a northward invasion. The Crystal Ball Cave assemblage confirms that U. cinereoargenteus has been expanding its range at the expense of V. vulpes.

Vulpes velox

Material--Left dentary with P/3 and partial M/1 (BYUVP 7477), posterior portion of left M/1 (BYUVP 7479). A partial left dentary with M/2 (BYUVP 7478) also compares favorably with this species.

Discussion--V. velox and V. macrotis are now considered conspecific (Hall 1981). The dentary (BYUVP 7477) lacks the "step" of Urocyon, and the M/1 lacks a small cuspule found on the posterolabial margin of the main cusp of all the Urocyon specimens but none of the Vulpes specimens examined. The Crystal Ball Cave specimens listed above are smaller than U. cinereoargenteus but may be similar in size to the smaller U. littoralis, which is known only from islands along the coast of southern California (Miller 1971).

Since V. velox still lives around Crystal Ball Cave (J. C. Bates 1983 personal communication), its presence in the assemblage is not surprising. Its low frequency compared to the now-extirpated V. vulpes suggests that it may not have always inhabited the area, may have inhabited it in much smaller numbers, or may have had a different microhabitat causing it to frequent the cave area less than V. vulpes. The ranges of V. vulpes and V. velox presently overlap to a degree, especially in the midwest, but in the western United States this overlap is small (Hall 1981). Although V. velox occurs in the Snake Range now, it is a more southern species than V. vulpes so its northern range extensions may be of Recent age.

Family Mustelidae
Mustela cf. frenata

Material--Left M1/ (BYUVP 7487), right dentary with P/2,/3, M/1,/2 (BYUVP 7483), partial right dentary without teeth (BYUVP 7484), left dentary with M/1,/2 (BYUVP 7488), left dentary with M/1 (BYUVP 7485), partial left dentary with M/1,/2 (BYUVP 7486).

Discussion--All these Mustela specimens compare best in size with M. frenata, which presently lives around Crystal Ball Cave. The size range of M. frenata is overlapped by the smaller but more variable M. erminea (Kurten and Anderson 1980) which also ranges in the cave area (Hall 1981). The specimens could belong to M. erminea since this species is dentally similar to M. frenata. M. rixosa is always smaller and M. nigripes and M. vison are always considerably larger than the Crystal Ball Cave specimens. M. frenata was the most abundant mustelid at Smith Creek Cave, but M. erminea was also present (Miller 1979). Since all the Crystal Ball Cave specimens fall in the narrow size range of M. frenata, they are referred to this species.

Mustela cf. vison

Material--Left M1/ (BYUVP 7482). A juvenile left dentary without teeth (BYUVP 7491) also compares well with this species.

Discussion--This isolated tooth was compared with a variety of Recent mustelids and other small carnivores and found most similar to M. vison. This is North America's largest extant species of Mustela (although the extinct sea mink, M. macrodon, was larger) and is distinctly larger than but similar in shape to M. frenata (described above). M. vison was recovered from Smith Creek Cave (Miller 1979) and presently occurs 100 miles (160 km) north and east of Crystal Ball Cave (Hall 1981), but it does not currently live in the Snake Range. This species requires lakes or streams to survive (Hall 1946), so its extirpated nature in the Snake Range may have been due to the recession of Lake Bonneville and/or loss of perennial streams in the area at the end of the Pleistocene.

M. vison is sometimes confused with M. nigripes since both are of similar size (Kurten and Anderson 1980), and no distinction in isolated molars could be found in the literature. M. nigripes is currently endangered, and no comparative material was available. It has never been reported from western Utah or Nevada, so the Crystal Ball Cave specimens are referred to M. vison, which is known to have lived in the area.

Martes americana

Material--Left dentary with M/1 (BYUVP 7480), left M/1 (BYUVP 7481). The anterior portion of a right dentary without teeth (BYUVP 7489) and the posterior portion of a right dentary without teeth (7523) probably also belong to this taxon.

Discussion--Anderson (1970), in her systematic review of the genus Martes, considered M. nobilis (found in four caves in Wyoming, Idaho, and northern California) to be a distinct species from M. americana. Of the two, M. nobilis is larger, and its lower carnasial has a relatively shorter trigonid. The lower canines of M. nobilis sometimes have faint grooves on the external surface not found in M. americana (Anderson 1970). The only other species of Martes presently living in Utah is M. pennanti, the fisher. It is considerably larger than M. americana, M. nobilis, and the Crystal Ball Cave specimens. Neither M. americana nor M. pennanti currently live in the Snake Range, but both occur in the mountains of central Utah and northward.

BYUVP 7480 is as large as the largest M. americana specimen to which it was compared, and judging from the incisor socket, its incisor was slightly larger. The other specimens are the same size as most Recent M. americana specimens. Both lower carnasials match perfectly in shape with M. americana and do not show a relatively shorter trigonid, so they are assigned to M. americana. A right M1/ of M. nobilis was recovered from Smith Creek Cave (Miller 1979) but M. americana has never been reported. The ecological and chronological separation of these two species in the Snake Range is, therefore, problematic. Brown (1971) listed M. americana as one of eight species of boreal mammals that presently range in the Sierra Nevada and the Rocky Mountains but on none of the isolated Great Basin ranges in between. This citing demonstrates that M. americana did range at least as far east in the Great Basin as the Snake Range before becoming extirpated.

Brachyprotoma brevimala, sp. nov.

Type--Anterior portion of skull including a complete palate except the most posterior (smallest) socket of each M1/ and extending posteriorly to include the entire anterior wall of the braincase (BYUVP 7490, see figure 5). Only the right P4/ was found in situ, but a right and left M1/ (previously cataloged as BYUVP 7492 and 8298 respectively) fit perfectly into the sockets of the type specimen where they have been permanently mounted. The type specimen is of a young adult based on complete fusion of the premaxillae, maxillae, nasals, and frontals and on lack of significant tooth wear. Both the skull and isolated M1/'s were recovered from Site 1, Channel A, Crystal Ball Cave, Millard County, Utah (see figures 1 and 3) by Wade E. Miller and party on March 19, 1977. The type specimen is housed at the Brigham Young University Vertebrate Paleontology Laboratory.

Diagnosis--Brachyprotoma brevimala has a short face and a maxillary tooth formula of I3/-3/, C1/-1/, P2/-2/, M1/-1/ as in B. obtusata. Face and maxillary dental measurements average 15% smaller than those of B. obtusata. B. brevimala is distinguished from B. obtusata by P4/ being transversely narrower and having a more posteriorly directed lingual cusp, and by M1/ being more reduced and distinctly shorter anteroposteriorly. In other known characters B. brevimala is equivalent to B. obtusata. B. brevimala has the most reduced P4/ and M1/ of any known skunk.

Description--The maxillary dental formula of I3/-3/, C1/-1/, P2/-2/, M1/-1/ is known among the mustelids only in two genera of skunks, Conepatus and Brachyprotoma (although I found one abnormal Recent Spilogale putorius specimen with this formula). The Crystal Ball Cave specimen is clearly a skunk (subfamily Mephitinae) based on the presence of only 2 pairs of upper premolars (mephitines have 2 or 3, all other mustelids have 3 or 4), the small size (only the subfamilies Mustelinae and Mephitinae have such small adult individuals), the lingual cusp of P4/ extending from the middle of the tooth (as opposed to the more anterior extension in the mustelines), M1/ being anteroposteriorly shorter labially than lingually (mustelines have the opposite condition), and the internal nares extending almost as far anteriorly as the posterior end of the tooth row (they are much more posterior in mustelines).

Compared to extant mephitines the Crystal Ball Cave specimen represents an individual of similar size to Spilogale but much smaller than Conepatus and Mephitis. The palate is shorter and wider than that of Spilogale putorius, but the interorbital breadth shows that the type specimen represents a larger individual than the average S. putorius. The P4/ is similar to Spilogale, differing only in having the lingual cusp slightly more posterior, but it is proportionally much narrower than the P4/ of Mephitis and Conepatus. The M1/'s are proximo-distally shorter than any of the living mephitines (especially Conepatus and Mephitis that have large square M1/'s) and are closest to Spilogale in shape and cusp pattern. The rostrum of the type specimen is shorter than that of Spilogale, matching that of Conepatus in proportions. The external nare is steep as in Conepatus, but it is relatively small and round as in Spilogale. Both infraorbital canals are single rather than double or triple, a species-diagnostic character in Conepatus (Hall 1981) but variable in Mephitis and Spilogale.

In addition to the three extant genera, three fossil genera have been named: Buisnictis, Brachyprotoma, and Osmotherium (Kurten and Anderson 1980). Osmotherium can be ruled out since it is large and very similar to Mephitis (Kurten and Anderson 1980), the living skunk genus that is most distinct from the Crystal Ball Cave specimen. Both Buisnictis and Brachyprotoma are small and have proportionally short jaws like the Crystal Ball Cave specimen. Buisnictis has been recovered from Late Pliocene deposits of southwestern Idaho (Bjork 1970) and Middle Pliocene to Early Pleistocene deposits of Kansas and Oklahoma (Hibbard 1941, 1950, 1954), but it has no record in the Late Pleistocene or Recent. Buisnictis has a short jaw with crowded premolars, but it differs from the Crystal Ball Cave specimen in having 3 pairs of upper premolars instead of 2 (Kurten and Anderson 1980). Based on an illustration by Hibbard (1954), the P4/ of Buisnictis has its lingual cusp extending from the anterior part of the tooth as in the mustelines, and the M1/ is distinctly longer than that of the Crystal Ball Cave specimen. These morphologic and age differences show that the Crystal Ball Cave specimen is distinct from Buisnictis.

The Crystal Ball Cave specimen matches the genus Brachyprotoma in having short jaws, only 2 pairs of upper premolars, P4/ and M1/ similar in shape and cusp pattern to Spilogale, and in the age of deposits in which they have been recovered. Until recently Brachyprotoma was only known from a few early Pleistocene to early Recent age ave deposits in the eastern United States. But during the period of this study P. M. Youngman (1984 personal communication) recovered several Brachyprotoma specimens from two cave deposits in the Yukon Territory of Canada. Although no previous Brachyprotoma specimens have been reported closer than 1130 miles (1880 km) from Crystal Ball Cave, morphology clearly allies the Crystal Ball Cave specimen with this genus. But there are specific differences between the Crystal Ball Cave specimen and other skulls which have been assigned to the genus Brachyprotoma. To test the amount of variation to be expected within a species of skunk, I measured 73 specimens of Recent Spilogale putorius, 60 from the Harvard University Museum of Comparative Zoology and 13 from the Brigham Young University Monte L. Bean Museum. Spilogale putorius makes a good standard for the expected individual variation in species of Brachyprotoma, both because Spilogale is probably the most closely related extant genus to Brachyprotoma and because S. putorius borders on being divisible into multiple species (although most workers presently consider it a single species). Based on the great amount of variation seen between the Crystal Ball Cave specimen and other skulls assigned to the genus Brachyprotoma compared with the amount of variation seen among individuals of S. putorius, I believe the Crystal Ball Cave specimen warrants the status of a new species.

The B. brevimala type is smaller than specimens of B. obtusata in most measured characters, averaging about 15% smaller (see table 3). The greatest differences occur in P4/ and M1/, which are the most varied maxillary teeth between skunk taxa. The mean length of P4/ in B. obtusata is only 7% greater than in B. brevimala while the mean width is 22% greater. The lingual cusp of P4/ in B. brevimala also points more posteriorly than in B. obtusata, being nearer M1/ at its lingual tip rather than closer at its base or parallel as in B. obtusata. The M1/ of B. obtusata is 16% transversely wider on the average, but the labial anteroposterior length is 30% greater and the lingual anteroposterior length is 59% greater than in the B. brevimala type on the average. Since there is only minor variation in these characters among B. obtusata skulls (see table 3) but distinct difference between them and the Crystal Ball Cave specimen, and because the differences between the B. brevimala type and specimens of B. obtusata are far greater than would be expected within a species (based on the variation found among 73 individuals of Spilogale putorius, the most closely related extant species), erection of a new species for the Crystal Ball Cave specimen is clearly justified.

Discussion--Brachyprotoma specimens have been previously recovered from the following deposits of Early Pleistocene to Early recent age: Port Kennedy Cave and Frankstown Cave, Pennsylvania (Cope 1899, Peterson 1926), Cumberland Cave, Maryland (Gidley and Gazin 1938), Crankshaft Cave and Brynjulfson Cave, Missouri (Oesch 1967, Parmalee and Oesch 1972, Parmalee et al. 1969), Connard Fissure, Arkansas (Brown 1908), and two caves in northern Yukon Territory, Canada (P. M. Youngman 1984 personal communication). Most of these specimens are lower jaws, and the only 7 skulls (or skull fragments) that have been previously reported are Carnegie Museum 11057A and 20233, American Museum of Natural History 11772 and 12426, U.S. National Museum 8155 and 11960, and a specimen identified as Carnegie Museum 308 by Oesch (1967) but which does not correspond to that number in the Carnegie Museum catalogs (M. R. Dawson 1984 personal communication). Parmalee et al. (1969) illustrated this latter specimen but did not identify it by catalog number.

Cope (1899) named Mephitis (Spilogale) obtusatus, for a single small dentary from Port Kennedy Cave, but E. D. Cope died before the completion of this paper, and a footnote stated that "none of the specimens labelled by Prof. Cope bear this name." Brown (1908) named the genus Brachyprotoma, and he considered M. obtusatus to belong to this genus as well as M. fossidens and M. leptops, two species named by Cope previous to the naming of M. obtusatus. From Connard Fissure Brown (1908) reported B. fossidens, B. leptops, and B. obtusatus based on dentaries, and he named B. pristina based on two partial skulls and three dentaries (the skull cataloged as American Museum of Natural History 12426 is the type for the genus and species) and B. spelaea based on one dentary. The dentaries Brown (1908) identified as B. fossidens and B. leptops are far too large to belong to the same genus as the small specimens he identified as B. obtusatus, B. pristina, and B. spelaea, and no one since has considered these two species as belonging to the genus Brachyprotoma. Later Hay (1923) named B. putorius from Frankstown Cave. Peterson (1926) identified material from Frankstown Cave as B. obtusata, correcting the specific ending to match the gender of the generic name.

The naming of multiple species of Brachyprotoma in the early publications listed above has been widely criticized by later workers because the variation among specimens is less than that seen within living species. Hall (1936) and Kurten and Anderson (1980) considered the genus Brachyprotoma to be clearly monotypic with the only valid species being B. obtusata, the earliest named species that can be applied to the genus. The Brachyprotoma skull from Crystal Ball Cave is the first specimen of Brachyprotoma distinct enough from B. obtusata to warrant the erection of an additional species of this genus.

Concerning the paleoecology of Brachyprotoma, Kurten and Anderson (1980) stated that this genus has always been associated with boreal faunas although other skunk genera were also recognized at each site. This matches the "more boreal than present" nature of the Crystal Ball Cave assemblage and suggests that the post-Pleistocene climatic shift may have lead, directly or indirectly, to the extinction of Brachyprotoma. Since fossils of Brachyprotoma are only found in a few deposits and even then are few in number, this genus probably never had a high density of individuals in life.

The Brachyprotoma brevimala type was first misidentified as Spilogale (Heaton 1984), the most similar living genus. Miller (1982) reported cf. Spilogale from Crystal Ball Cave, possibly based on this same specimen. Mephitis was also mentioned in my preliminary report (Heaton 1984), but further examination proved that the anterior right dentary (BYUVP 7489) upon which the identification was based was equally referable to Martes americana, which is represented by additional material. Although both Mephitis mephitis and Spilogale putorius (=gracilis) now inhabit the Snake Range (Hall 1981), and Spilogale has been recovered from deposits over 12,000 years old in Smith Creek Cave (Mead et al. 1982), their presence is unconfirmed in the Crystal Ball Cave assemblage.

Since Brachyprotoma seems to have lived contemporaneously with other skunk genera, it is interesting to speculate about how their niches varied. All living skunks tend to be nocturnal and omnivorous, so they are rarely tied to specific foods or habitats. Minor niche differences do occur between living North American genera: Spilogale is the most carnivorous, Mephitis the most herbivorous, and Conepatus the most insectivorous. Spilogale has narrow sharp teeth, Conepatus at the other extreme has very broad teeth, and Mephitis is intermediate but has the longest tooth rows. Brachyprotoma (especially B. brevimala) has pushed the narrowing of the teeth seen in Spilogale to an extreme, converging on the carnivorous genus Mustela. This suggests that Brachyprotoma was more carnivorous than any of the living skunks.

Why Brachyprotoma lost P2/ and shortened its tooth rows, paralleling the genus Conepatus, is a mystery. Members of the genus Mustela have longer tooth rows than skunks, so in that respect Brachyprotoma diverged from Mustela. Brachyprotoma was trending in a direction that is difficult to explain. Brachyprotoma also did not survive the post-Pleistocene changes as did the aforementioned genera (although some species were lost and ranges altered). I propose that these two facts are correlated. Brachyprotoma was probably adapting to a specialized niche that existed during the Pleistocene but disappeared during the Recent. I also propose that this specialization was a feeding habit and/or preference for a particular prey item since the specializations discussed are all dental. No postcranial material has been reported to document additional specializations, and skunks' most diagnostic characters, scent glands and color patterns, are in the soft anatomy which is obviously unavailable. With such limited data (about 27 specimens from 9 sites), further speculation would be unwarranted. All that can be concluded is that Brachyprotoma was restricted to boreal conditions, was widespread in North America, was probably low in density, and did not survive the post-Pleistocene changes.

The evolution of the genus Brachyprotoma has been discussed by Kurten and Anderson (1980). They stated that it seems most closely related to Spilogale, but both were probably derived from the Mio-Pliocene genus Promephitis. No intermediate forms are available to show the exact phylogeny, however. Some speculation can be made about the relationship of B. brevimala to B. obtusata. B. brevimala has gone to a greater extreme in the characters that differentiate Brachyprotoma from other skunks (shorter face and narrower teeth) and is therefore more specialized. Since specialists almost always evolve from generalists, B. brevimala probably evolved from B. obtusata. The fact that B. obtusata has been found in deposits from early Pleistocene to early Recent age (Kurten and Anderson 1980) while B. brevimala is known only from a late Pleistocene to Recent deposit also supports this conclusion.

Family Felidae
Smilodon cf. fatalis

Material--Partial left ectocuneiform (BYUVP 7530), claw (BYUVP 7497). Miller (1982) reported cf. Smilodon from Crystal Ball Cave based on a single vertebra (W. E. Miller 1983 personal communication), but this specimen is apparently lost (possibly due to an explosion that affected the collection).

Discussion--The ectocuneiform is dense, worn, and coated with a calcite crust. The claw is missing the outer plates but is otherwise in good condition. The specimens were compared with Smilodon and Felis atrox, the only two late Pleistocene cats large enough to be considered, and both compare best with Smilodon (W. E. Miller 1984 personal communication). The ectocuneiform was previously referred to Panthera atrox (Heaton 1984), but comparison with actual specimens rather than casts shows that it was clearly Smilodon. The only previous citing of Smilodon in Utah is from the Silver Creek fauna of north-central Utah (Miller 1976), but it has been found in Pleistocene assemblages throughout North America.

Kurten and Anderson (1980) considered S. fatalis to be the only valid species of late Pleistocene Smilodon in North America, but it has been known by many other names. Based on this synonymy, the Crystal Ball Cave specimens are referred to S. fatalis although they are doubtfully species specific.

Felis concolor

Material-First right metacarpal (BYUVP 7502), 4 claws (BYUVP 7498-7501).

Discussion-F. concolor is the only cat of its size presently living in North America, but similar-sized species of Acinonyx and Homotherium existed during the Pleistocene. Lynx and other species of Felis (disregarding those often placed in the genus Panthera) are distinctly smaller than F. concolor, and Smilodon, Panthera atrox, and P. onca are distinctly larger. The Crystal Ball Cave specimens were compared with material of Felis species, Acinonyx, and Homotherium at the Los Angeles County Museum and found to match perfectly in size and shape with F. concolor but to clearly differ from the other felids mentioned. F. concolor presently lives throughout the Snake Range (Hall 1981), and J. C. Bates (1983 personal communication) reported a citing in the Snake Valley near Gandy as well as many higher in the mountains.

Lynx cf. rufus

Material--Right C1/ (BYUVP 7494), right P/4 (BYUVP 7496). The anterior portion of a right maxilla without teeth (BYUVP 7495) is probably also referable to Lynx.

Discussion--L. rufus currently inhabits the area of Crystal Ball Cave (J. C. Bates 1983 personal communication) while L. canadensis ranges only as close as central Utah and northward and prefers colder climates (Hall 1981). L. canadensis is slightly larger than L. rufus and has considerably larger feet (Ingles 1965). The specimens recovered fall in the size range of both L. rufus and L. canadensis, but they tend to be closer in size to L. rufus. None of the claws recovered could be referred to this genus, so the difference in foot size was not helpful. Since L. rufus presently lives around the cave, the specimens are referred to it.

Order Perissodactyla
Family Equidae
Equus cf. scotti

Material--Left cuneiform (BYUVP 7542), right lunar (BYUVP 7544), 2 right scaphoids (BYUVP 7549, 7550), right magnum (BYUVP 7561), second phalanx (LACM 123683), third phalanx (BYUVP 7595). A juvenile left P/2 (BYUVP 7623), a partial juvenile first phalanx (BYUVP 7586), a second phalanx (BYUVP 7588), 3 partial third phalanges (BYUVP 7596, 7607, 7608), and a distal sesamoid (BYUVP 7622) probably belong to this species also. Phalanx measurements are listed in tables 4, 5, and 6.

Discussion--Several species of large horses have been recognized from the late Pleistocene of western North America. The Rancho La Brea asphalt deposits have yielded a single species of large horse (Savage 1951) usually referred to E. occidentalis (Merriam 1913, Stock 1963, Willoughby 1974), although the validity of this name has been questioned (Miller 1971). Based on comparative material and measurements made by Willoughby (1974), the large Crystal Ball Cave horse is distinct from the Rancho La Brea horse in having more transversely broad phalanges (see figures 6, 7, and 8) and carpals with relatively larger articulation surfaces. The Crystal Ball Cave specimens are distinctly larger than E. niobrarensis based on measurements given me by A. H. Harris (1983 personal communication) and in Harris and Porter (1980). A. H. Harris (1983 personal communication) also provided me with measurements of E. pacificus (although the validity of this species has been questioned by Savage 1951) from Fossil Lake, Oregon, and phalanges of this species match well in size with the large Crystal Ball Cave horse but are not as transversely broad.

Gazin (1936) listed measurements of the type specimen of E. scotti, and of all specimens and data seen, only it has phalanges that are as transversely broad as the Crystal Ball Cave specimens. The second phalanx (LACM 123683) is slightly larger than the E. scotti type but has identical proportions (see figure 7), and the third phalanx (BYUVP 7595), although smaller because it is of a subadult, has the same proportions as the anterior third phalanges of the E. scotti type (see figure 8). Dalquest (1964) stated that E. scotti was very heavily built, and this would suggest that the foot and toe bones are broad compared with other species of Equus. The large carpals from Crystal Ball Cave mentioned above, especially the cuneiform and magnum, are broad and have much larger articulation surfaces than the Rancho La Brea horse. Based on this limited information in the literature, the largest carpals listed above compare most favorably with E. scotti also.

E. scotti was originally named and described from Texas by Gidley (1900), and most specimens have been found in that state (Dalquest 1964, Gidley 1903, Johnston 1937). Hopkins et al. (1969) recovered a left metatarsal from the Late Pleistocene American Falls Lake Beds of southeastern Idaho that they referred to E. scotti. It is therefore not unlikely that E. scotti lived in Utah. A large horse was represented at Smith Creek Cave by a single vestigial metapodial (Miller 1979), but no attempt was made to identify it to species.

BYUVP 7588 is not as laterally broad as LACM 123683 but is too large to belong with the smaller species. The epiphysis is not fully fused, showing that it represents a subadult. It is the only bone from Crystal Ball Cave that matches well with the Rancho La Brea horse, although it is slightly smaller. But since it may differ by only individual, foot, or age variation from the better represented E. cf. scotti, it is tentatively referred to that species.

Equus ? conversidens

Material--Right M3/ (LACM 123677), thoracic vertebra (BYUVP 7687), 3 right pisiforms (BYUVP 7536-7538), left pisiform (BYUVP 7539), 2 right cuneiforms (BYUVP 7540, 7541), 4 right lunars (BYUVP 7543, 7545-7547), partial left lunar (BYUVP 7548), 4 right scaphoids (BYUVP 7551-7558), 4 partial left scaphoids (BYUVP 7555-7558), 2 right trapezium-trapezoids (BYUVP 7559, 7560), 2 right magnums (BYUVP 7562, 7563), partial right magnum (BYUVP 7564), left magnum (LACM 123678), 2 partial right unciforms (BYUVP 7565, 7566), proximal tibia epiphysis (BYUVP 7570), distal epiphysis of right tibia (BYUVP 7571), partial distal epiphysis of left tibia (BYUVP 7572), right calcaneum (LACM 123679), left calcaneum (BYUVP 7573), right astragalus (BYUVP 7575), right juvenile astragalus (BYUVP 7574), left astragalus (LACM 123680), right navicular (BYUVP 7576), left navicular (BYUVP 7577), left cuboid (BYUVP 7579), right meso-ento (BYUVP 7578), proximal portion of left metatarsal (BYUVP 7567), 2 distal metapodial epiphyses (BYUVP 7568, 7569), 6 first phalanges (BYUVP 7580, 7581, 7583, LACM 123684, 123685), 3 partial first phalanges (BYUVP 7582, 7584, 7585), 5 second phalanges (BYUVP 7589, 7593, 7594, LACM 123684, 123685), 4 partial second phalanges (BYUVP 7587, 7590-7592), 5 third phalanges (BYUVP 7597, 7600, 7601, 7605, 7606), 2 partial third phalanges (BYUVP 7602, 7603), juvenile third phalanx (BYUVP 7610), 11 proximal sesamoids (BYUVP 7611-7621). Phalanx measurements are listed in tables 4, 5, and 6.

Discussion--In addition to the fossils of large horses from Crystal Ball Cave (referred to E. cf. scotti) are numerous bones of small horses. Some of these compare well with E. conversidens, the species to which most small Pleistocene North American horse fossils have been assigned, while others do not. Considerable time has been spent evaluating the size and morphologic variation among these bones and comparing the results with descriptions and measurements in the literature. But both complexities within this collection and disagreements regarding valid species in the literature have prevented positive species identification of these small horse bones.

E. conversidens (Owen 1869) has been considered by some to be the only species of small Pleistocene horse in North America (Harris and Porter 1980, Miller 1971), and most other named species of small Pleistocene horses have at some time been synonymized with this species (Dalquest and Hughes 1965, Hibbard 1955, Hibbard and Taylor 1960). However most workers presently recognize at least two species. Owen (1869) named E. tau at the same time he named E. conversidens. Poor illustrations of the type specimens have caused some workers to consider E. conversidens and E. tau synonymous (Hibbard 1955). But Dalquest (1979) and Mooser and Dalquest (1975), after researching the early descriptions (the type specimen of E. tau is lost), considered these two species distinct. The teeth that Mooser and Dalquest (1975) assigned to E. tau are smaller than those of E. conversidens, and the metapodials are longer and more slender. Skinner (1942) assigned a first phalanx from Papago Springs Cave, Arizona to E. tau because it was much narrower than those of E. conversidens from the same assemblage. But based on his measurements this phalanx is narrower transversely than anteroposteriorly, making it doubtful of being horse at all.

Hay (1915) named E. francisci, which was synonymized with E. conversidens by Hibbard and Taylor (1960). But Lundelius and Stevens (1970) reprepared the metatarsal of the type specimen and found it to be distinctly longer and narrower than that of E. conversidens. Lundelius and Stevens (1970) therefore considered E. francisci a valid species, and they synonymized E. quinni (based on the similar long metatarsal) and Onager zoyatalis (based on dental similarities) to it. Dalquest (1979) considered E. francisci, as well as E. littoralis, E. achates, and E. quinni, to be synonymous with E. tau, and he considered E. conversidens and E. tau the only two valid species of small Pleistocene North American horses.

Based on an illustration in Lundelius and Stephens (1970), the M3/ of E. francisci is distinctly wider transversely than that of E. conversidens although they are of similar anteroposterior length. LACM 123677, although quite worn, has the same width and length as the E. francisci type and has an enamel pattern most similar to it also. Dalquest (1979) synonymized E. francisci with E. tau, but the M3/ of the lectotype of E. tau illustrated by Mooser and Dalquest (1975) is not transversely broad like the E. francisci type and Crystal Ball Cave M3/. Unfortunately the only phalanx measurements given in the literature are for E. conversidens, except the questionable first phalanx assigned to E. tau by Skinner (1942).

The only phalanges from Crystal Ball Cave that compare well with measurements of E. conversidens phalanges in the literature are three of the five second phalanges (see figure 7). The other two second phalanges (BYUVP 7593, 7594) are distinctly smaller than any assigned to E. conversidens yet have complete epiphyseal fusion. All nine first phalanges are from individuals intermediate in size between those represented by the two sets of second phalanges, and all are small compared with the first phalanges assigned to E. conversidens in the literature (see figure 6). Six of the seven third phalanges articulate well with the three larger second phalanges yet are smaller than the third phalanges assigned to E. conversidens in the literature (see figure 8). The other third phalanx (BYUVP 7600) is larger than any assigned to E. conversidens and too large to articulate with any of the second phalanges under discussion.

It is important to consider sexual dimorphism, individual variation, and variation among different feet of the same individual to see how much variation is expected within a species. Willoughby (1974), in a table of bone measurements from 25 species and races of Equus, listed mean dimensions for both sexes with respect to two characters: metacarpal mid-width and metacarpal mid-width divided by length. Metacarpals of males had a mid-width of 3.1% to 7.3% greater than females and a mid-width divided by length of 2.3% to 6.9% greater than females. Species with more sexual dimorphism in metacarpal width tended to also have more dimorphism in width relative to length, so male metacarpals tend to be more robust and just slightly longer than female metacarpals. These measurements show that sexual dimorphism is not great in Equus and certainly not sufficient to have caused the variability seen among the small Crystal Ball Cave equids.

Howe (1970), in a study of Equus (Plesippus) simplicidens, showed that individual variation in bone size can be greater than previously thought. Because the large number of specimens at Nebraska's Broadwater Quarry fell into a single size curve with no gaps, he concluded that they all represent a single species, and he synonymized a number of species which had previously been named based on limited material at other sites. Table 5 of Howe (1970) shows that the largest metacarpal and metatarsal lengths and widths average 32% larger than the smallest corresponding measurements, and none are more than 36% larger. Even with a sample size of 97 to 190, the metapodials measured by Howe (1970) show less variation than do the few second and third phalanges from Crystal Ball Cave.

Isolated front and rear phalanges are usually indistinguishable and therefore have an additional degree of variation. Front and rear phalanx measurements were taken from recent E. caballus and E. burchelli specimens, and the larger measurements for each species averaged 4.2% larger than the smallest corresponding measurements with a maximum of 9.4% larger. But even this much variability, in addition to sexual and individual variation, does not adequately account for the great size range among the small Crystal Ball Cave equids.

Six measurements of the 5 second phalanges from Crystal Ball Cave (excluding those referred to E. scotti) show that the largest measurements are 24% to 43% larger than the smallest corresponding measurements with an average of 31.5% larger. Eleven measurements of the 9 third phalanges from Crystal Ball Cave show that the largest measurements are 7% to 122% larger than the smallest corresponding measurements with an average of 50.7% larger. Considering the second and third phalanges separately, each have enough variation to make it marginal whether they could all be assigned to the same species considering sexual, individual, and foot variation. The variation seems even more extreme when one considers that the smallest second phalanges (BYUVP 7593, 7594) are from much smaller individuals than the smallest third phalanx, and the largest third phalanx (BYUVP 7600) is from a larger individual than the largest second phalanx. This is far more variation than can be accounted for by the sexual, individual, and foot variation for a single species as discussed above, and it suggests that multiple species of horse smaller than E. cf. scotti are represented at Crystal Ball Cave.

Finding a dividing line between two species in this material is nearly impossible, however. Most of the material could be assigned to a species of horse 15% smaller than E. conversidens, but the two smallest second phalanges (BYUVP 7593, 7594) and the largest third phalanx (BYUVP 7600) seem too far from the mean to belong to this supposed species. Until more phalanx measurements are available for small Pleistocene horses other than E. conversidens, it is difficult to determine how many species are represented by the smaller Equus fossils from Crystal Ball Cave and whether most of the material represents an unusually small variety of E. conversidens, a species distinct from E. conversidens such as E. tau and/or E. francisci, or both.

Order Artiodactyla
Family Camelidae
Camelops cf. hesternus

Material--Right scaphoid (LACM 123686), left scaphoid (LACM 123687), left lunar (BYUVP 7624), left magnum (BYUVP 7625), right unciform (BYUVP 7626), distal fragment of metapodial (BYUVP 7629), 2 first phalanges (BYUVP 7627, LACM 123689), proximal portion of first phalanx without epiphysis (LACM 123691), partial proximal epiphysis of first phalanx (BYUVP 7638), 3 second phalanges (LACM 123692, BYUVP 7630, 7632), 3 proximal portions of second phalanges (BYUVP 7633, 7634, 7637), 3 partial proximal portions of second phalanges (BYUVP 7628, 7635, 7636), 3 third phalanges (BYUVP 7639, 7641, 7642). Six sesamoids (BYUVP 7644-7649) are probably of Camelops but may represent Bison. Phalanx measurements are listed in tables 7, 8, and 9.

Discussion--Webb (1965, 1974) recognized only four valid genera of late Pleistocene North American camels: Titanotylopus, Camelops, Hemiauchenia (=Tanupolama), and Paleolama (in order of decreasing size). Titanotylopus is somewhat common and Camelops is very common in late Pleistocene assemblages of western North America, but neither has been found in the east (Webb 1974). Hemiauchenia is found in late Pleistocene deposits throughout the Americas (Webb 1974) and is commonly associated with Camelops (Miller 1979). Paleolama has only been found in Florida, Texas, and southern California in Pleistocene deposits of North America (Miller 1976). Miller (1982) identified Camelops and Hemiauchenia from Crystal Ball Cave.

The specimens listed above fall within the range of variation of Camelops hesternus measurements from Rancho La Brea, southern California (Webb 1965) and Selby and Dutton, eastern Colorado (Graham 1981). T. E. Downs (1984 personal communication) provided me with 8 first phalanx measurements of Titanolopus sp., 21 of Camelops hesternus, and 21 of Hemiauchenia sp. from southern California deposits. Those of Titanolopus range from 105 to 138 mm in length with an average of 121 mm, those of Camelops hesternus range from 105 to 125 mm in length with an average of 116 mm, and those of Hemiauchenia range from 91 to 110 mm in length with an average of 94 mm. The two complete first phalanges from Crystal Ball Cave, both of which are of adults based on epiphyseal fusion and bone density, measure 114 and 117 mm in length (see table 7). Although there is some overlap in first phalanx length between these genera, the Crystal Ball Cave specimens clearly match best with Camelops.

Savage (1951) recognized four valid species of Camelops: C. hesternus and C. huerfanensis, which are larger, and C. sulcatus and C. minidokae, which are smaller; and Webb (1965), in his detailed description of Camelops, supported this system. Based on limb bone measurements given by Savage (1951), C. minidokae was about 14% smaller than C. hesternus. C. huerfanensis can only be distinguished from C. hesternus and C. sulcatus can only be distinguished from C. minidokae based on dental characters (Graham 1981, Savage 1951). Both C. minidokae and C. sulcatus are too small to match the Crystal Ball Cave specimens, and both are known only from pre-Wisconsinan deposits (Kurten and Anderson 1980).

C. hesternus and C. huerfanensis are very similar and may be conspecific (Hopkins 1955, Savage 1951). Both are known from the late Pleistocene, and both are known from Idaho (Gazin 1935, Hopkins 1955, Hopkins et al. 1969) and Colorado (Cragin 1892, Graham 1981). C. hesternus is the only species of Camelops reported from Utah. A Camelops hesternus skull was recovered from a lava tube 87 miles (140 km) east-southeast of Crystal Ball Cave (Romer 1928, 1929) and dated at 11,075 =225 Y.B.P. (Nelson and Madsen 1979). Camelops cf. hesternus was reported from the Silver Creek fauna in north-central Utah (Miller 1976). Camelops sp. was reported from Smith Creek Cave (Harrington 1934, Stock 1936, Miller 1979), but the only material mentioned is a right navicular (Miller 1979), and no attempt was made to identify it to species.

Since the Crystal Ball Cave specimens match measurements of C. hesternus by T. E. Downs (1984 personal communication), Graham (1981), and Webb (1965), and since C. hesternus is the only species reported from the state of Utah, the Crystal Ball Cave specimens are referred to this species. But since the only diagnostic character to distinguish C. hesternus from C. huerfanensis is a dental feature not applicable to the Crystal Ball Cave specimens (Hopkins 1955, Savage 1951), C. huerfanensis cannot be positively eliminated on the basis of these foot elements.

Hemiauchenia cf. macrocephala

Material--Distal right portion of metapodial (LACM 123688), first phalanx (LACM 123690), partial proximal portion of first phalanx (BYUVP 7640), second phalanx (BYUVP 7631). Phalanx measurements are listed in tables 7, 8, and 9.

Discussion--Two genera of small camels are recognized from the Pleistocene of North America: Hemiauchenia and Paleolama (Webb 1974). Based on illustrations of Hemiauchenia (=Tanupolama) macrocephala (=stevensi) by Stock (1928) and Paleolama mirifica by Webb (1974), the metapodials of H. macrocephala are 63% longer but 3% transversely narrower at the distal end than those of P. mirifica. The Crystal Ball Cave metapodial fragment is 12% transversely narrower than the H. macrocephala specimens illustrated by Stock (1928) and measurements from the Vallecito Creek and Ringold sites of southern California provided by T. E. Downs (1984 personal communication). The first phalanges from Crystal Ball Cave fall well within the range of Hemiauchenia specimens reported by T. E. Downs (1984 personal communication), McGuire (1980), and Schultz (1937). Nothing was available to compare the second phalanx with, but it is from the same size of camel as the other elements. The Crystal Ball Cave specimens clearly match the more narrow-legged Hemiauchenia rather than the more broad-legged Paleolama.

Webb (1974) synonymized the North American genus Tanupolama with the South American genus Hemiauchenia and recognized six valid species. Of these, only H. macrocephala is found in the late Pleistocene of North America. H. macrocephala represents the synonymy of a number of previously named North American species (Webb 1974), and it is the best-known Pleistocene llama (Kurten and Anderson 1980). Since only this species matches the age and locality of the Crystal Ball Cave assemblage, and since the Crystal Ball Cave specimens match specimens from other sites assigned to this species, the four Crystal Ball Cave specimens are referred to H. macrocephala. Characters separating this species from others of Hemiauchenia are almost entirely dental (Webb 1974), however, and are therefore not applicable to the Crystal Ball Cave material.

Miller (1982) reported Hemiauchenia from Crystal Ball Cave based on the same material reported here. Miller (1979) reported ? Hemiauchenia sp. from Smith Creek Cave based on a left cuboid, the proximal portion of a scapula, and a juvenile metapodial. Hemiauchenia is better represented than Camelops at Smith Creek Cave by a ratio of 3 to 1, but Camelops is better represented than Hemiauchenia at Crystal Ball Cave by a ratio of 7 to 1. This difference seems even more dramatic in light of the selection for smaller bones at Crystal Ball Cave but not at Smith Creek Cave. Although this difference could be explained by slight age differences in these faunas, human intervention, or chance preservation, I feel it is more likely due to habitat differences between these two genera of camels.

Kurten and Anderson (1980) stated that ". . . Hemiauchenia had a long stride and was highly cursorial. It was a plains-dweller and probably fed primarily on grass." About Camelops they stated: "Although primarily a grazer, Camelops, with its long neck and legs, was probably an occasional browser." Although these two camels are thought to have been plains-dwelling grazers, it is interesting to speculate about their habitat differences. Webb (1974) presented strong evidence that Hemiauchenia gave rise to the mountainous living South American llamas. Camelops, on the other hand, probably resembled the living dromedary camel (Kurten and Anderson, 1980) which prefers flat plains habitats. The fact that Camelops is by far the better represented camel at Crystal Ball Cave, located in a small outlier surrounded by a flat valley, while Hemiauchenia is better represented at nearby Smith Creak Cave, located in a canyon at the base of a high mountain, suggests that Hemiauchenia preferred higher elevations and/or more rugged terrain than Camelops.

Family Cervidae
cf. Cervus elaphus

Material--First phalanx (BYUVP 7811).
Discussion--Several cervid phalanges from Crystal Ball Cave are intermediate in size between Cervus and Odocoileus. BYUVP 7811 (60.2 mm long) is the largest of these and is much closer in size to Cervus. In comparison with the others it is distinctly larger and more robust, yet high bone porosity suggests that it is of a sub-adult. Navahoceros fricki is another late Pleistocene cervid found as close to Utah as Arizona and Wyoming, and its size is intermediate between Odocoileus and Cervus (Kurten and Anderson 1980). No character has been described to differentiate phalanges of Navahoceros and Cervus, and no comparative material of Navahoceros was available to the author. C. elaphus was recovered from Smith Creek Cave (Miller 1979) and has been reported living in the Snake Range in Recent times (Hall 1981), so the phalanx is referred to this species.

Odocoileus hemionus

Material--Partial right dentary with P/3,/4, M/1 (BYUVP 7651) and anterior left dentary with P/3,/4, M/1,/2 (BYUVP 7650, probably from the same individual), partial right dentary with P/3 (BYUVP 7652), left patella (BYUVP 7934). Of 21 first and 51 second phalanges of non-camelid artiodactyls, most compare best in size and proportions with Odocoileus.

Discussion--BYUVP 7650 and 7651 are of a juvenile and compare best in size and degree of hypsodonty with juvenile individuals of O. hemionus. The P/4's in these dentaries have 3 lobes rather than 2, a condition seen in juveniles of Odocoileus but not Antilocapra. The P/3 of BYUVP 7652 is identical to adult O. hemionus and distinctly larger and less hypsodont than A. americana. The first and second phalanges from Crystal Ball Cave that compare best with Odocoileus have a slightly larger mean size than those of Recent O. hemionus living in Utah. This demonstrates that the Crystal Ball Cave specimens are of O. hemionus rather than the smaller O. virginiana (Hall 1981), and it suggests that deer decreased in size at the end of the Pleistocene much like Ovis canadensis did (Harris and Mundel 1974).

Based on numbers of phalanges, Odocoileus is the best represented artiodactyl in the Crystal Ball Cave assemblage; but Antilocapra americana is now the dominant artiodactyl of the local fauna. Odocoileus sp. was reported at Smith Creek Cave by Goodrich (1965), but no material was found by Miller (1979). Mule deer now live in Smith Creek Canyon (Miller 1979) and sometimes come down to Gandy at night to feed in cultivated fields (J. C. Bates 1984 personal communication). The replacement of Odocoileus by Antilocapra, suggested by comparison of the Crystal Ball Cave assemblage with the living community, shows that plant communities preferred by deer apparently moved upward in altitude from Snake Valley to higher elevations in the Snake Range at the close of the Pleistocene.

Family Bovidae
Antilocapra americana

Material--Partial left maxilla with M1/,2/,3/ (BYUVP 7656).

Discussion--The M3/ was distinguished from Odocoileus by being very hypsodont and having a more pointed posterior end as in Antilocapra. It is identical in size and proportions to the largest male specimen of A. americana available for comparison and distinctly larger than the extinct Pleistocene antilocaprids.

Since A. americana presently lives around Gandy Mountain in small herds, it is not surprising to find it in the assemblage. But it is not well represented as a fossil, suggesting that Snake Valley has not always been the treeless desert that it is now. Since Odocoileus hemionus is the dominant artiodactyl in the fossil assemblage while Antilocapra americana is the dominant living artiodactyl in the area, Antilocapra americana must have become abundant in the area in Recent times at the expense of Odocoileus hemionus.

Ovis canadensis

Material--Posterior portion of lower right jaw with M/1,/2,/3 (LACM 123695) and posterior portion of lower left jaw with M/3 (LACM 123696, probably from the same individual), left magnum (BYUVP 7780).

Discussion--The molars of LACM 123695 and 123696 are distinctly larger and more robust than Ovis aries and are even slightly larger than Recent Ovis canadensis. This suggests that the jaws are Pleistocene rather than Recent in age because Harris and Mundel (1974) demonstrated that O. canadensis became reduced in size at the end of the Pleistocene.

Pleistocene bighorn sheep are commonly found in assemblages in the Great Basin (Hibbard and Wright 1956, Stokes and Condie 1961). Even in historic times they have been reported natively in the Snake Range (Durrant 1952, Hall 1946, 1981). O. canadensis was temporarily lost from the Snake Range but was reintroduced in the middle 1900s and presently thrives in the higher elevations (Mead et al. 1982). Shortly after this reintroduction, one young ram lived on Gandy Mountain for several months (J. C. Bates 1983 personal communication), but this is the only citing I know of at such a low elevation in the area.

Ovis Canadensis is the best represented ungulate in the Smith Creek Cave assemblage, and Oreamnos harringtoni is also well represented (Miller 1979). No Oreamnos material has been identified from Crystal Ball Cave, and Ovis is less represented than horse, camel, and deer. This difference between the two assemblages is probably because wild goats and sheep are mountainous animals and would rarely venture into Snake Valley. It may also represent the fact that Smith Creek Cave was a shelter for humans since many Ovis fossils found there appear butchered (Miller 1979).

Ovis cf. aries

Material--Right metacarpal and two first phalanges found associated (BYUVP 8300).

Discussion--These associated bones were found as float near the east entrance of Crystal Ball Cave, and their greasy appearance suggests that they are Recent. The length and shape of the metapodial demonstrates that it is of the genus Ovis, and it is slightly longer than the O. aries specimens to which it was compared but distinctly smaller than living O. canadensis. O. aries is now a common domestic animal in the area, and many roam on Gandy Mountain each winter (J. C. Bates 1984 personal communication).

Since this species is a Recent introduction from Europe, its presence has little significance to this study. It does show, however, that the smaller bones of large mammals are still being deposited in Crystal Ball Cave, probably by woodrats since gates on the cave entrances would keep out all but the smallest carnivores. These specimens were found just north of the east entrance, an area where woodrats and their nests are often found.

cf. Symbos cavifrons

Material--Second phalanx (BYUVP 7923), distal portion of second phalanx (BYUVP 7924), 2 partial second phalanges (BYUVP 7925, 7926), 2 distal portions of second phalanges (BYUVP 7921, 7922).

Discussion--These short, broad second phalanges compare best among living species to Ovibos moschatus but are slightly longer and narrower. BYUVP 7923 is the most complete specimen, missing only one side of the distal extension. It has a length of 42 mm, a proximal transverse width of 27 mm, and a proximal anteroposterior width of 26 mm. BYUVP 7924 has the same proximal measurements as BYUVP 7923, and BYUVP 7925 has a proximal anteroposterior width of at least 26 mm. The distal ends taper in such a way that they are hard to measure. The general shape of these second phalanges shows that they are from an animal more closely related to Ovibos than any other living bovid. Few phalanx measurements of Pleistocene oxen are available, but Nelson and Madsen (1980) and Stokes and Hansen (1937) reported abundant isolated Symbos cavifrons and Bootherium bombifrons crania from Lake Bonneville deposits, and McGuire (1980) reported Euceratherium from a late Pleistocene deposit in central Nevada.

Kurten and Anderson (1980) described Symbos cavifrons as being taller and more slender than Ovibos moschatus, and this description matches the difference between the Crystal Ball Cave specimens and Ovibos moschatus perfectly. Bootherium is smaller than Symbos and is thought by many to represent females or juveniles of that genus (Kurten and Anderson 1980, Nelson and Madsen 1980). Euceratherium was larger and more heavily built than Ovibos (Kurten and Anderson 1980), and a first phalanx illustrated by McGuire (1980) is far too big at the distal end to match the second phalanges from Crystal Ball Cave. So although no comparative material was available, both the description and known range of Symbos cavifrons make the Crystal Ball Cave specimens most referable to that species.

This study was supervised by Wade E. Miller who helped in collecting and identifying specimens and preparing the manuscript. His insistence that every identification be backed by thorough research and explanation has made a lasting impression on me. Thanks is also due Kenneth L. Stadtman and Clyde L. Pritchett for providing comparative specimens and help in identification. Jerald C. and Marlene Bates of Gandy allowed me access to Crystal Ball Cave on many occasions and provided helpful information on the history and original condition of the cave, as well as the mammals that currently live in the immediate area. The Los Angeles County Museum generously loaned me the Crystal Ball Cave specimens in their possession so they could be included in this study.

Howard C. Stutz identified the plants, Lee F. Braithwaite the gastropods, and Stephen L. Wood the beetle. John A. White provided information valuable for identifying the lagomorphs. Elaine Anderson provided information helpful in evaluating the Brachyprotoma skull. Phillip M. Youngman provided unpublished information and measurements on Brachyprotoma specimens he recovered from Yukon Territory, Canada. Arthur H. Harris provided bone measurements for several species of horses. Theodore E. Downs gave me information on Pleistocene horses and measurements of Pleistocene camels. Jim I. Mead identified some of the bovid specimens and provided other helpful encouragement. Wade E. Miller, J. Keith Rigby, Morris S. Petersen, Lehi F. Hintze, Elaine Anderson, and Phillip M. Youngman made critical reviews of the manuscript. Thanks is especially due my wife, Julie, for help with collection and curation of specimens, gathering of literature, and preparation of the manuscript.

This study was funded by grants from the National Speleological Society and Associated Students of Brigham Young University, by a private donation from Herbert H. Gerisch, and by Brigham Young University research assistantships to the author. Publication costs were paid for by the Joseph M. and Jessie K. D. Savage Endowment of the Brigham Young University Monte L. Bean Museum and the Brigham Young University College of Physical and Mathematical Sciences.