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

THE QUATERNARY PALEONTOLOGY AND PALEOECOLOGY OF CRYSTAL BALL CAVE, MILLARD COUNTY, UTAH: WITH EMPHASIS ON THE MAMMALS AND THE DESCRIPTION OF A NEW SPECIES OF FOSSIL SKUNK

Timothy H. Heaton

Department of Geology, Brigham Young University, Provo, Utah 84602

ABSTRACT

Crystal Ball Cave is located in a small outlier of the Snake Range in Snake Valley 1 mile (1.7 km) from Lake Bonneville at its highest level. Original vertebrate skeletal material (mostly mammalian) is found in shallow dry dust 200 feet (61 meters) inside the cave. Radiocarbon dates show that fossils have been accumulating since at least 23,000 Y.B.P. It appears that wood rats and possibly small carnivores transported the fossils into the cave because only the smallest elements of large mammals are represented.

The fossil assemblage represents a much more boreal community than the present local fauna. Fish, Ondatra zibethicus, and Mustela cf. vison, which require perennial water, were recovered, as were Ochotona princeps, Lepus cf. americana, Microtus cf. pennsylvanicus, Vulpes vulpes, and Martes americana, which have also been extirpated from the Snake Range. Marmota flaviventris, Neotoma cinerea, cf. Cervus elaphus, and Ovis canadensis were recovered but now occur only at higher elevations in the range. Extinct taxa recovered are Smilodon cf. fatalis, Equus species, Camelops cf. hesternus, Hemiauchenia cf. macrocephala, cf. Symbos cavifrons, and a new species of Brachyprotoma, herein named B. brevimala. This is the first recovery of Brachyprotoma from the western United States.

INTRODUCTION

Crystal Ball Cave is located 3 miles (4.8 km) northwest of the town of Gandy, Utah and 0.6 miles (0.9 km) east of the Utah-Nevada border (Sec. 30, T15S, R19W, Salt Lake Base Line and Meridian) in the northeast side of Gandy Mountain, a small outlier on the northeastern edge of the Snake Range (see figures 1 and 2). The cave is at an elevation of 5775 feet (1760 meters), 644 feet (195 meters) above Lake Bonneville at its highest level (see Currey 1982, Gilbert 1890), and has about 500 feet (150 meters) of passage and a floor area of about 20,000 square feet (1860 square meters). Calcite crystals and speleothems cover most of the cave walls and floors, but some shallow sediments are present which contain locally abundant unaltered vertebrate fossils.

It is uncertain if native Americans knew of Crystal Ball Cave, for no ancient human artifacts were found in this study. The cave was discovered by the late George Sims of Gandy in February, 1956. He found the original 3 foot (1 meter) diameter entrance that leads into a large chamber (see figure 3). The original east entrance was enlarged, the north entrance was blasted out through a soil-filled passage at the other end of the cave (see figure 3), and other improvements were made by Cecil R. and Jerald C. Bates of Gandy, Utah and Thomas E. Sims of Elko, Nevada (J. C. Bates 1983 personal communication).

Herbert H. Gerisch and Robert Patterson collected bones from Site 1 (see figure 3) in 1956 that they donated to the Los Angeles County Museum (H. H. Gerisch 1983 personal communication). Later Michael Stokes of the Los Angeles County Museum collected additional specimens from Site 1. These early collections consisted of float only and included bones of extinct horses and camels. On at least one of these early expeditions, some specimens were also collected from Gandy Mountain Cave, a smaller cave that lies about 1/4 mile (0.4 km) south of and 100 feet (30 meters) higher than Crystal Ball Cave. Specimens from these two caves are indistinguishable in the Los Angeles County Museum collection because the cave in which each specimen was recovered was not recorded. I dug several test pits in Gandy Mountain Cave in 1981 and found preservation to be poor and specimens to be few and probably all Recent. So although some specimens were collected from Gandy Mountain Cave, they are not considered in this study, except some which may be among the Los Angeles County Museum collection.

The first extensive collecting in Crystal Ball Cave was done in 1977 by Wade E. Miller and his students from Brigham Young University who used fine screens to obtain thousands of specimens (all from Site 1). Miller (1982) described this investigation and listed the genera identified in a report on vertebrate fossils from Lake Bonneville deposits. Wade E. Miller and I operated similar collecting projects in 1981 and 1982 (Sites 1, 2, and 3), and I wrote a preliminary report on this study (Heaton 1984). Crystal Ball Cave is Los Angeles County Museum locality 4534 and Brigham Young University vertebrate paleontology locality 772; the specimens from the cave are cataloged as LACM 123655-123711 and BYUVP 5300-8888, 8911-8933. Taxa recovered are listed in table 1.

The Crystal Ball Cave assemblage is the first late Wisconsinan age fauna to be described from the state of Utah. Although Utah has extensive Pleistocene deposits from Lake Bonneville, surprisingly few vertebrate fossils have been recovered from them (Miller, 1982). The only other Pleistocene assemblage that has been described from Utah is the Silver Creek fauna of north-central Utah, 14 miles (22 km) east of and 1,200 feet (360 meters) above Lake Bonneville's highest level and of late Sangamon to early Wisconsinan age (Miller 1976).

The nearest described Pleistocene vertebrate localities are four shelters located in Smith Creek Canyon, White Pine County, Nevada, 9 miles (14 km) south of Crystal Ball Cave. New species of mountain goat (Stock 1936), eagle (Howard 1935), and gigantic vulture (Howard 1952) were described from Smith Creek Cave, the primary site. Literature on the Smith Creek Canyon sites includes a description of the avifauna by Howard (1952), the micromammalian fauna by Goodrich (1965), the herpetofauna by Brattstrom (1976), the whole fossil assemblage by Miller (1979) and Mead et al. (1982), and the archaeology by Bryan (1979), Harrington (1934), and others. Although the Crystal Ball Cave fauna is chronologically and geographically close to that of Smith Creek Canyon, it differs in having its fossils deep in the cave, and this has resulted in significant differences between these assemblages. Crystal Ball Cave, for example, has more abundant mammal fossils but less abundant bird fossils than the Smith Creek Canyon sites.

The Crystal Ball Cave assemblage contains only small bones with a maximum length of about 10 cm and maximum weight of about 50 grams. This has caused some problems in identifying the large species since only the smallest elements, which have rarely been considered in other studies, are represented. The assemblage, however, is very large and is important since few assemblages of late Pleistocene age have been reported from the region. The size of this assemblage and the time restraints upon the project have limited the depth to which each taxon could be studied. For taxa with large numbers of specimens, only the best specimens were considered. Additional work could turn up more species, and statistical studies on the more abundant taxa could yield much additional information.

GEOLOGY OF THE CAVE

The Snake Range is a north-south trending Basin and Range horst composed of early Paleozoic rocks. Gandy Mountain, where Crystal Ball Cave is situated, is an outlier of this range (Gilbert 1890, Nelson 1966). The cave lies in unnamed Middle Cambrian limestone on the upper plate of the Snake Range Thrust Fault, which is exposed at the north and south ends of Gandy Mountain (Nelson 1966). The massive beds around the cave strike N35W and dip 20NE (Halliday 1957), following the local trend throughout Gandy Mountain (Nelson 1966). The limestone is cavernous and contains many small solution cavities, in addition to Crystal Ball and Gandy Mountain Caves.

I have recognized four distinct stages of the cave's history: 1) a period of dissolution of limestone to form the cave, 2) a period of precipitation forming a layer of large calcite crystals ("nail head" spar) up to 1 foot (0.3 meters) thick on the cave walls, ceiling, and floor, 3) a period of partial dissolution of these crystals in the upper portions of the cave, the appearance of joints that cut the large calcite crystals, and the dislodging of breakdown from the ceiling of the large entrance room, and 4) the formation of vadose calcite speleothems and influx of sediment and fossils from outside the cave.

The beginning of stage 1, the dissolution of the cave, is of uncertain date. Davis (1930) demonstrated that limestone dissolution to form caves occurs predominantly in a thin zone just below the water table which is rich in carbon dioxide from groundwater percolating down from the surface. Once it reaches the water table, this groundwater dissolves the rock as it moves very slowly down the water table slope (Davies 1960). This appears to be the case in Crystal Ball Cave, since no scalloped or stream-cut passages are present to suggest the presence of fast-moving water expected in an above water table origin (Malott 1938, Myers 1969). The cave tends to parallel the strike of the beds and is relatively horizontal, as would be expected if the cave were formed at the water table. Green (1961) cited evidence that some caves in western Utah predate the tilting associated with the Basin and Range uplift. The fact that Crystal Ball Cave is roughly horizontal and parallel to the strike of the beds suggests that it postdates this tilting. But since the cave is high in a small isolated hill, considerable uplift and/or erosion must have taken place since the cave was at the water table. The cave does not parallel the present land surface as the water table tends to do (Myers 1969), and this further suggests that much overburden has been removed since the original dissolution of the cave.

Stage 2, the precipitation of large calcite crystals, represents a different groundwater environment than the preceding dissolutional stage. It is generally agreed that such "nail head" spar forms in still, calcite-saturated water where nucleation centers are free to grow into large euhedral crystals (Hill 1976). This shift from dissolution to precipitation does not necessarily represent a significant change in the level of the water table, but it does represent the drastic reduction in the carbon dioxide content of the groundwater necessary for calcite precipitation (Moore and Nicholas 1964). Several vertical cavities (domes) extend upward into the cave ceiling, and these predate the calcite precipitation because they are partly filled by it. Moore and Nicholas (1964) cited evidence that such domes form late in cave dissolution and provide more direct water and air connections to the surface. Myers (1969) stated that they are of vadose (above water table) origin and caused by vertical seepage. Perhaps the formation of these domes allowed gas exchange between the groundwater in the cave and the surface permitting carbon dioxide to escape and calcite to be precipitated.

Stage 3 includes several events which are not chronologically separable. Some of the calcite crystals in the roof of the cave are completely dissolved, and locally some of the limestone bedrock underneath it is also. This is especially evident in the aforementioned domes. Joints and breakdown, both of which cut the previously formed calcite crystals, probably represent one or several earthquakes. If any uplift postdates the cave's origin, it probably occurred during this stage. These cracks and breakdown blocks were later filled and covered by the speleothems of stage 4, showing their chronologic relationship.

Stage 4 postdates the loss of voluminous standing water in the cave and the opening of entrances large enough to allow considerable gas exchange and sediment into the cave. Vadose speleothems such as the stalactites, columns, and rimstone pools found in Crystal Ball Cave form subaerially in caves having enough gas exchange with the surface to allow carbon dioxide to escape from the dripping groundwater (Moore and Nicholas 1964). Near the east entrance of the cave some small columns have formed upon and been partly covered by sediment coming in from the entrance, showing the concurrence of these events. The vertebrate material under study entered the cave during stage 4 when cave opening(s) were sufficiently large to allow their entry and dry conditions allowed their preservation; therefore cave stages 1 through 3 predate the oldest fossils.

Twelve sediment samples were collected at sites throughout the cave and screened to determine the degree of sorting. All samples are poorly sorted, but samples farthest from known entrances tend to have a higher percentage of fine particles. Particles under 0.0024 inch (0.061 mm) in diameter make up over half the weight percent of three such samples. Samples were placed in hydrochloric acid to remove all calcite. Sediment from Site 1 (see figure 3) is composed of about 80% calcite and 20% very fine but poorly sorted clastic grains, namely quartz, mica, and an unidentified ferromagnesian mineral. Larger clastic grains were found in samples closer to each entrance and comprised greater portions of the sediment.

The calcite portion of the sediment is composed of both crystal fragments, probably derived from broken "nail-head spar," and cryptocrystalline caliche-like crust associated with clastic fragments, almost certainly precipitated in the cave. The clastic fragments could have been washed in, blown in, brought in by animals, or been released from the cave walls as impurities in the limestone. The sediments at Site 1 show no sign of ever having been wet except in some areas where they have been cemented with calcite. But water runs in through the east entrance during storms filling the large entrance chamber with mud. Wind gusts can be quite strong through the cave during storms, but only because the north entrance was opened by man. The importance of these factors is difficult to determine, but the fact that the bulk of the sediment far inside the cave is calcite demonstrates that the sediments are mostly derived from within the cave by weathering of the limestone and calcite crystals rather than from outside sources.

METHODS

The dry, dusty sediments of Sites 1 and 2 are composed of nearly 10% vertebrate bones by volume. These fossiliferous sediments are unstratified and never more than 1.5 feet (0.5 meters) thick, so no meaningful relative dating is feasible. Collecting was done mainly at Sites 1 and 2, but a few specimens were taken from Sites 3 and 4 (see figure 3). No significant differences were found between fossils from the various sites, so the site at which each specimen was collected is not reported here but can be found in the Brigham Young University Vertebrate Paleontology Laboratory catalogs.

On early collecting trips most of the field time was spent digging through the sediments and collecting specimens by hand. Sediment was also taken to the lab in bags and screened in order to recover smaller bones and teeth. After using this method for several trips, the collection had overwhelming numbers of rodent and lagomorph fossils, but bones of larger mammals were few. So on the last collecting trip large volumes of cave sediment were screened inside the cave with a coarse screen, and the number of larger bones in the collection was thereby more than doubled.

Little laboratory preparation was necessary with the larger Crystal Ball Cave fossils. A few required removal of hardened dirt or calcite. All were washed to remove dust. Considerable time was spent manually separating small bones and teeth from cave sediments. This was done in the laboratory with forceps after the sediments had been washed through a fine screen and allowed to dry. Approximately 35 cubic feet (1 cubic meter) of cave sediment was prepared in this manner, and virtually all the bone was removed.

Because of the great abundance of small mammal fossils recovered, only the skulls and jaws were studied. All identifiable material was used for larger mammals because they were not as well represented and because few dental elements were recovered. Identification was made by comparison to Recent specimens housed at the Brigham Young University Monte L. Bean Museum, fossil specimens housed at the Brigham Young University Vertebrate Paleontology Laboratory, and by extensive use of the literature.

Small living mammals were captured inside Crystal Ball Cave and around Gandy Spring at the base of Gandy Mountain. This trapping was not extensive, but it did indicate what species are abundant in and around the cave. The species trapped are recorded in table 1. Jerald C. and Marlene Bates of Gandy (1983 personal communication, 1984 personal communication) were interviewed for additional information about the modern local fauna and recent history of the cave including modification by man.

ANTIQUITY OF THE ASSEMBLAGE

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.

PALEOECOLOGICAL SETTING

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.

SYSTEMATIC PALEONTOLOGY

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 c