Sullivan et al., eds., 2011, Fossil Record 3. New Mexico Museum of Natural History and Science, Bulletin 53. 641 CAPROMERYX (ARTIODACTYLA:ANTILOCAPRIDAE) FROM THE RANCHOLABREAN TRAMPEROS CREEK FAUNA, UNION COUNTY, NEW MEXICO, WITH A REVIEW OF THE OCCURRENCE AND PALEOBIOLOGY OF CAPROMERYX IN THE RANCHOLABREAN OF NEW MEXICO RICHARD S. WHITE, JR.1 AND GARY S. MORGAN2 1 International Wildlife Museum, 4800 West Gates Pass Road, Tucson, AZ 85745; 2 New Mexico Museum of Natural History and Science, 1801 Mountain Rd. NW, Albuquerque, NM 87104 Abstract—Tramperos Creek is an open site in Union County, northeastern New Mexico, which has produced a Rancholabrean vertebrate fauna characterized by the presence of Bison and Mammuthus. A partial skull with both right and left horn cores of Capromeryx furcifer is described from this site in which the anterior prong of the horn core is reduced to little more than a nubbin of bone about 3 mm in height. This represents the most extreme reduction in the anterior prong of the horn core of Capromeryx yet known. We suggest that the anterior prong may not have been expressed at all in the keratinous horn sheath, or that, alternatively, a fairly substantial keratinous expression of the anterior sheath may have been present despite the absence of a concomitantly developed horn core. We further speculate that the reduction in the anterior prong may have been associated with a progressive invasion of less-open vegetation and the adoption of a more solitary life style, paralleling similar differences in the elaboration of cranial appendages in living bovids and cervids. INTRODUCTION 103°33’W longitude, and the elevation is 4,890 ft. (1,490 m). Tramperos Creek is an intermittent stream that flows eastward into Texas where it We document here the occurrence in the Tramperos Creek Local eventually becomes a tributary of the Canadian River. Although the creek Fauna (Rancholabrean) of an example of Capromeryx furcifer with ex- is mostly dry, a pond or wet marsh is periodically present in a low area treme reduction of the anterior tine of each horn core, so that the tine may just northwest of the outcrops. The Tramperos Creek site was discov- not have been expressed in the external keratin sheath covering the horn ered in April 2002 by Ken Garrison and was worked by NMMNH field core. The skull described here is an adult, most likely male, individual crews in May 2002 and August 2004. Morgan and Lucas (2005) briefly with posterior horn cores at least 115 mm in height. The anterior horn reviewed the vertebrate fauna. cores are reduced to small points only 3 mm in height. We note that The fossils occur in nearly vertical outcrops along the south and Capromeryx in the Rancholabrean of New Mexico is known from 14 east sides of Tramperos Creek. The exposed section is about 200 m long different localities, mostly cave sites, but never in abundance. This may and reaches a maximum of 10 m in thickness. The outcrop is broadly reflect a taphonomic bias, or it may be related to the behavior of the horseshoe-shaped, trending almost east-west for about 100 m and then diminutive pronghorn. taking a sharp bend north for another 100 m. Fig. 2 is a stratigraphic The fossils from the Tramperos Creek Local Fauna are housed in section measured about midway along the Tramperos Creek exposures, the vertebrate paleontology collection of the New Mexico Museum of near site TC 6 where a Mammuthus tooth was collected. The section Natural History and Science (NMMNH). Other specimens of consists of unnamed Quaternary alluvium composed of fine-grained sedi- Rancholabrean Capromeryx from New Mexico are cited from the follow- ments, silt and silty sand in the lower 3-4 m, clays in the upper 4-5 m, ing museums: Natural History Museum of Los Angeles County (LACM), and a 1 m thick soil horizon at the top. Bones occur primarily in the Los Angeles, California; Museum of Comparative Zoology (MCZ), lower 3 m, which consists of mottled bluish-gray to yellowish-orange Harvard University, Cambridge, Massachusetts; Maxwell Museum of silts and silty sands and dark brown clays. This lower part of the section Anthropology (MMA), University of New Mexico, Albuquerque; Shuler also contains abundant freshwater mollusks, as well as fish, frogs, sala- Museum of Paleontology (SMP), Southern Methodist University, Dal- manders, and muskrats, indicating the former presence of permanent las, Texas; Texas Memorial Museum (TMM), University of Texas, Aus- water such as a stream or pond. tin, Texas; University of Arizona Laboratory of Paleontology (UALP), Large mammals are fairly common in the Tramperos Creek fauna, Tucson, Arizona; United States National Museum (USNM), Washing- with the most widespread taxa being an extinct species of Bison, the large ton, D.C. (USNM); Laboratory for Environmental Biology, Centennial camel Camelops, and the horse Equus. There are also several concentra- Museum (UTEP), University of Texas at El Paso, Texas; University of tions of small vertebrates in the lowermost part of the stratigraphic California Museum of Paleontology (UCMP), Berkeley, California; section. One of these sites is composed mostly of small terrestrial verte- Florida Museum of Natural History (UF), University of Florida, brates, including toads, ground squirrels, pocket gophers, and rabbits, Gainesville. Other abbreviations used are Local Fauna (LF), kiloanna or whereas the second site has a large component of freshwater vertebrates, thousands of years before present (ka), kilometer (km), meganna or including small fish, frogs, and salamanders, as well as rodents and other millions of years before present (Ma), meters (m), North American land- small terrestrial species, particularly snakes. The Tramperos Creek ver- mammal “age” (NALMA), and United States Geological Survey (USGS). tebrate fauna consists of 30 species, including at least 13 species of lower LOCALITY AND GEOLOGY vertebrates (fish, amphibians, reptiles, and birds) and 17 species of mam- mals (Table 1). The Tramperos Creek Local Fauna (NMMNH site number L- Parts of three individuals of Bison were excavated from a small 5083) is located just west of the old Woodson Ranch (identified as area at the base of the stratigraphic section at the northern end of the “Miera” on the Minnie Butte USGS 7.5 minute quadrangle), about 50 outcrop. Two of these specimens consist of partial articulated postcra- km southwest of Clayton in southern Union County, northeastern New nial skeletons, but no skulls or horn cores have been found that would Mexico (Fig. 1). Coordinates for the site are 36°05’N latitude and allow us to make a positive species-level identification, although the 642 FIGURE 2. Stratigraphic section measured at Tramperos Creek, Union County, New Mexico. (Morgan and Lucas, 2003; Morgan et al., this volume). Most of the Rancholabrean records consist of limited samples of isolated teeth and/or postcranial elements that are identified as Capromeryx primarily on the FIGURE 1. Map of New Mexico showing the location of Pleistocene basis of their small size. Capromeryx is the only very small ruminant (Rancholabrean and Irvingtonian) sites with Capromeryx. 1, Tramperos artiodactyl known from late Pleistocene faunas in New Mexico. Most of Creek, Union County; 2, Perico Creek, Union County; 3, Blackwater Draw, these specimens are here referred to Capromeryx sp., although they Roosevelt County; 4, Sandia Cave, Sandoval County; 5, Doolittle Cave, probably belong to the small species C. furcifer, the only recognized Grant County; 6, U-Bar Cave, Hidalgo County; 7, Conkling Cavern, Doña Rancholabrean member of the genus (see taxonomic discussion below). Ana County; 8, Shelter Cave, Doña Ana County; 9, Pendejo Cave, Otero Among the 13 New Mexico Rancholabrean faunas with County; 10, Algerita Blossom Cave, Eddy County; 11, Big Manhole Cave, Capromeryx, three are open or stratified sites and ten are caves. The Eddy County; 12, Dry Cave, Eddy County; 13, Muskox Cave, Eddy County; three open sites are all located in northeastern New Mexico, including 14, Slaughter Canyon Cave, Eddy County. Map modified from Degenhardt Tramperos Creek and Perico Creek in Union County and Blackwater et al. (1996). Draw in Roosevelt County (Fig. 1). Tramperos Creek is the only Pleis- tocene open site in New Mexico containing fossils of Capromeryx that extinct Bison antiquus is most likely. Bison antiquus is the only species are diagnostic at the species level, consisting of the posterior portion of reported from late Rancholabrean faunas in New Mexico, while Bison the skull with both horn cores intact, described herein. latifrons in known from earlier Rancholabrean sites. Bison latifrons is The Perico Creek site is located along the north side of Perico much larger than the bison represented by the two partial skeletons from Creek on the Kiowa National Grassland, about 15 km southeast of Clayton Tramperos Creek. The large sample of aquatic vertebrates and associated in Union County in northeastern New Mexico just west of the Texas line freshwater mollusks from the lower part of the section, as well as the (Fig. 1, site 2), and about 60 km northeast of the Tramperos Creek site. fine-grained sediments in which the fossils occur, suggest a quiet-water The fossiliferous unit is a channel sand deposit 3-5 m thick, overlying the depositional environment. Miocene Ogallala Formation and about 1-2 m below the local land sur- The Tramperos Creek LF is Rancholabrean in age based on the face. The vertebrate fossils occur mostly as isolated elements in a tan, presence of Bison and Mammuthus columbi, but no further refinement of fine clayey to silty sand with abundant small freshwater bivalves and the age is possible. We submitted a sample of bone from the Capromeryx freshwater and terrestrial gastropods, indicating a freshwater deposi- skull to Beta Analytic, Inc. for an AMS radiocarbon date; however, the tional environmental such as a small stream or pond. The Perico Creek specimen did not contain enough collagen for a reliable date. There are vertebrate fauna consists of about 15 species, including a single postcra- several reasons that a bone sample may lack sufficient collagen for dat- nial element of Capromeryx, as well as Equus sp., the peccary Platygonus ing, including an age greater than 50 ka or leaching of the organic matter compressus, Camelops hesternus, and Mammuthus sp. (Schumacher, from the bone. Numerous attempts by the junior author and others to 2001; Morgan and Lucas, 2005). An Irvingtonian or Rancholabrean age is date bones from Rancholabrean open sites in New Mexico have been indicated by the presence of Mammuthus. Although the site lacks Bison, unsuccessful, including sites that were thought to date between 10 and the presence of the small peccary Platygonus compressus suggests a 20 ka based on other data, suggesting that leaching of collagen from the Rancholabrean age. bone may be a recurring problem. The Blackwater Draw Fauna (also known as Blackwater Draw CAPROMERYX FROM THE Locality 1, the Clovis site, and the Brown Sand Wedge and Gray Sand RANCHOLABREAN OF NEW MEXICO Local Faunas) is located in Blackwater Draw, about 16 km southwest of Site Descriptions Clovis and about 10 km north of Portales in northeastern Roosevelt County in east-central New Mexico (Fig. 1, site 3). Although better Capromeryx is known from 13 late Pleistocene (Rancholabrean) known as a Paleoindian archaeological site (Hester, 1972; Haynes, 1995; faunas in New Mexico, including Tramperos Creek, and one mid Pleis- Holliday, 1997, 2005), Blackwater Draw has the most diverse late Pleis- tocene (late Irvingtonian?) cave site (Fig. 1). Capromeryx also occurs in tocene vertebrate fauna known from an open site in New Mexico six late Pliocene and early Pleistocene (Blancan) faunas in New Mexico (Lundelius, 1972; Slaughter, 1975; Morgan et al., 2001). Two latest  643 TABLE 1. Vertebrate faunal list for the Rancholabrean (late Pleistocene) graphic superposition over a thickness of about 2 m of section and Tramperos Creek Local Fauna, Union County, New Mexico. Extinct species represent a time interval of less than 3000 years (radiocarbon ages be- indicated by “†.” tween 11 ka and 13 ka: Haynes, 1995), and lack notable differences in their large mammal faunas. Therefore, Morgan and Lucas (2005) com- bined the vertebrate assemblages from the Gray Sand and Brown Sand Wedge Local Faunas into the more inclusive Blackwater Draw Fauna, which includes all late Pleistocene (late Rancholabrean) vertebrates from Blackwater Draw Locality 1. In addition to the latest Pleistocene radio- carbon dates, a Rancholabrean age for the Blackwater Draw is indicated by the presence of the dire wolf Canis dirus, Bison antiquus, and Mammuthus columbi (Lundelius, 1972). The Brown Sand Wedge LF has a rich microvertebrate fauna obtained primarily by screenwashing (Slaugh- ter, 1975). The screenwashing of sediment from the Brown Sand Wedge also produced a distal radius-ulna and a hoof of Capromeryx sp. The northernmost New Mexico cave containing Capromeryx is Sandia Cave, located in the Sandia Mountains about 20 km northeast of Albuquerque in Sandoval County (Fig. 1, site 4). At an elevation of 2208 m, Sandia Cave is also the highest site in New Mexico with Capromeryx. Like Blackwater Draw, Sandia Cave is a well known latest Pleistocene archaeological site, and was one of the first sites in North America where Paleoindian artifacts were found in association with extinct Pleistocene megafauna (Hibben, 1941). There are at least eight species of large extinct mammals in the Sandia Cave collection at the Maxwell Museum of An- thropology at the University of New Mexico, including the Shasta ground sloth Nothrotheriops shastensis, Equus sp., Camelops hesternus, the big-headed llama Hemiauchenia macrocephala, the American mastodon Mammut americanum, and Mammuthus columbi, as well as an upper molar of Capromeryx sp. (Thompson and Morgan, 2001; Thompson et al., 2008). Three radiocarbon dates on collagen from large mammal bones from Sandia Cave range from 11-14 ka (Haynes and Agogino, 1986). Doolittle Cave is a rock shelter situated at an elevation of 1640 m in a canyon west of the Mimbres River in southeastern Grant County in southwestern New Mexico (Fig. 1, site 5). It appears that there must have been a Rancholabrean level beneath the rich archeological deposit reported by Cosgrove (1947). A horn core of Capromeryx is known from Doolittle Cave (Cosgrove, 1947). The specimen (MCZ 15238 M) is the base of a left horn core. U-Bar Cave is located in the Alamo Hueco Mountains in Hidalgo County, at an elevation of 1540 m, in the Bootheel region of southwest- ern New Mexico, approximately 10 km from the border with the Mexi- can state of Chihuahua (Fig. 1, site 6). U-Bar Cave consists of a large chamber with an extensive accumulation of sediment that was mined for fertilizer. This cave has a diverse late Rancholabrean vertebrate fauna, including Capromeryx and the larger antilocaprid Stockoceros, as well as Nothrotheriops shastensis, Canis dirus, the giant short-faced bear Arctodus simus, several species of Equus, the extinct mountain deer Navahoceros fricki, Bison, and the shrub ox Euceratherium collinum (Harris, 1985a, 1993). U-Bar Cave is the southernmost and westernmost record of Capromeryx from New Mexico (31°28’ North, 108°26’ West). Harris (1993) reported Capromeryx sp. in both mid Wisconsinan and late Wisconsinan stratigraphic units in U-Bar Cave, with radiocarbon ages ranging from about 13-36 ka. Conkling Cavern is located on the eastern slope of Bishop’s Cap (also known as Pyramid Peak), a limestone peak at the southern end of the Organ Mountains, about 15 km southeast of Las Cruces in Doña Ana County in southern New Mexico (Fig. 1, site 7). It lies at an elevation of 1299 meters. Conkling Cavern and the nearby Shelter Cave (see below) were discovered by Roscoe Conkling and excavated in 1929 and 1930 by Pleistocene (late Rancholabrean) vertebrate faunas have been named from field parties from the Natural History Museum of Los Angeles County Blackwater Draw based on the stratigraphic units from which they were (LACM). Besides Capromeryx, other large mammals from Conkling derived, the Gray Sand LF (Lundelius, 1972) and the Brown Sand Wedge Cavern include Nothrotheriops shastensis, Canis dirus, Equus, Camelops, LF (Slaughter, 1975). The Gray Sand immediately pre-dates Paleoindian Hemiauchenia, and Bison (Conkling, 1932; Harris, 1993, 2011). Although occupation of this region, whereas Clovis artifacts are found in the Brown the fauna from Conkling Cavern is almost certainly late Rancholabrean in Sand Wedge, together with remains of extinct Pleistocene megafauna age, there are no available radiocarbon dates to confirm the age. (Haynes, 1995). The Gray Sand and Brown Sand Wedge occur in strati- Shelter Cave is on the western slope of Bishop’s Cap in Doña Ana 644 County in southern New Mexico, about two miles west of Conkling Platygonus compressus occur only in the older Dry Cave sites, whereas Cavern (Fig. 1, site 8) but somewhat higher in elevation at 1475 meters. the American lion Panthera atrox, Equus conversidens, E. francisci, E. As its name indicates, Shelter Cave is a rock shelter. The vertebrate fauna niobrarensis, and Bison antiquus are found only in the younger series of includes the antilocaprids Capromeryx and Stockoceros conklingi (Stock, sites (Harris, 1985b, 1993, 2011). 1930, 1932), as well as Nothrotheriops shastensis, two species of Equus, Muskox Cave (Fig. 1, site 13) is in Carlsbad Caverns National and Camelops. Shelter Cave has one of the largest samples of Capromeryx Park in Eddy County, on the eastern escarpment of the Guadalupe Moun- furcifer known from New Mexico, including a horn core, maxilla, man- tains at an elevation of about 1600 m. The Pleistocene entrance to the dible, and numerous postcranial elements. Radiocarbon ages on three cave was a sinkhole about 20 m in diameter and about 35 m deep that coprolites of Nothrotheriops from Shelter Cave range from 11-12.5 ka appears to have functioned as a natural trap (Logan, 1981). The diverse (Thompson et al., 1980). mammalian fauna of nearly 50 species includes nine members of the Pendejo Cave is located in Rough Canyon, about 20 km east of Pleistocene megafauna: Canis dirus, Panthera atrox, the cheetah-like cat Orogrande on the Fort Bliss Military Reservation in Otero County, Miracinonyx trumani, Equus, Capromeryx furcifer, Stockoceros conklingi, southeastern New Mexico, at an elevation of 1490 meters (Fig.1, site 9). Euceratherium collinum and Harrington’s extinct mountain goat Oreamnos It is a rather small cave, but preserves a diverse fauna of late Rancholabrean harringtoni. Capromeryx is represented by a skull (USNM 521305) and vertebrates dating from the mid to late Wisconsinan (about 11 to >55 ka; a small sample of postcranial elements. Radiocarbon dates on bone col- Harris, 2003, 2011). Capromeryx occurs in both mid and late Wisconsinan lagen from Muskox Cave range from 18-26 ka (Logan, 1981). strata in Pendejo Cave, and is represented by a nearly complete horn core Slaughter Canyon Cave (also known as New Cave) is located in of C. furcifer (= C. minor) (Harris, 2003, 2011). Other extinct mammals Carlsbad Caverns National Park in Eddy County at an elevation of 1517 from the Pendejo Cave fauna include Nothrotheriops shastensis, two m (Fig. 1, site 14), about 14 km southwest of Carlsbad Cavern. Slaughter species of Equus, Camelops, Hemiauchenia macrocephala, Stockoceros Canyon Cave contains extensive guano deposits that were mined for conklingi, and Bison antiquus. fertilizer until the 1950s. The vertebrate fauna of about 15 species is Five caves in the vicinity of the Guadalupe Mountains in Eddy overwhelmingly dominated by the extinct free-tailed bat Tadarida County in southeastern New Mexico have produced specimens of constantinei (Lawrence, 1960; Morgan, 2002). There are only two large Capromeryx, including Algerita Blossom Cave, Big Manhole Cave, Dry mammals in the fauna, the extinct mountain deer Navahoceros fricki, Cave, and Muskox Cave, all of late Pleistocene age (Harris, 1993), and represented by two nearly complete skeletons, and several isolated post- Slaughter Canyon Cave of mid Pleistocene age, probably late Irvingtonian cranial elements of Capromeryx (Morgan and Lucas, 2006). Uranium- (Lundberg and McFarlane, 2006; Morgan and Lucas, 2006; Polyak et al., series dates of 209 ka (Lundberg and McFarlane, 2006) and 212 ka 2006). Harris (1993) listed Capromeryx sp. from Dark Canyon Cave (Polyak et al., 2006) were obtained from a calcite flowstone layer over- near Carlsbad in Eddy County, but this material has since been reidenti- lying the guano deposit containing the Slaughter Canyon Cave vertebrate fied as Stockoceros (Harris, 2011). fauna. Polyak et al. (2006) proposed an age greater than 400 ka Algerita Blossom Cave is located west of Carlsbad between (Irvingtonian) for the guano deposit and vertebrate fauna. McKittrick Cave and Dry Cave (Fig. 1, site 10) at 1280 m. The cave DESCRIPTION OF TRAMPEROS CREEK CAPROMERYX opening is a fissure that was excavated by cavers (Harris, 2011). Algerita Blossom Cave has a mammalian fauna of 35 species, including four Material: NMMNH 50387 (Fig. 3 A-E): partial skull consisting members of the Pleistocene megafauna: Nothrotheriops shastensis, the of right and left horn cores, most of the frontals and parietals, part of the Mexican horse Equus conversidens, Hemiauchenia macrocephala, and basicranium, part the occipital shield and miscellaneous cranial frag- Capromeryx sp. (Harris, 1993, 2011). The fauna suggests a late Ranchola- ments. Skull lacks the rostrum and dentition; the mandible is likewise brean age. absent. Collected May 30, 2002 by Gary S. Morgan and Kenneth Garri- Big Manhole Cave is located just north of Carlsbad Caverns Na- son. tional Park near Lechuguilla Cave (Fig. 1, site 11). The small entrance at Description: Both right and left horn cores are nearly complete. an elevation of 1280 m leads to a large chamber almost 30 m in diameter The left horn core posterior prong is nearly complete, lacking an esti- located about 20 m below the opening (Harris, 2011). Radiocarbon dates mated 10-15 mm of the tip. The left anterior prong is complete. The right range from 20-25 ka (Stafford in Harris, 2011). The mammalian fauna of horn core is less well preserved, but still substantially complete. The Big Manhole Cave consists of 37 species, including eight members of the missing portion of the tip is estimated to be at 30-35 mm in length. The Pleistocene megafauna: Equus conversidens, E. niobrarensis, Camelops, right anterior prong is complete. Hemiauchenia macrocephala, Navahoceros, Capromeryx sp., The larger posterior prongs as preserved are 105 mm (left) and 85 Stockoceros conklingi, and Bison sp. (Harris, 1993). mm (right) in length, measured from the saddle between the prongs. Dry Cave is located about halfway between the Pecos River to the They are estimated to have been approximately 115 mm in length when east and the Guadalupe Mountains to the west, about 24 km west of complete. Both posterior prongs are straight, without any suggestion of Carlsbad in Eddy County at an elevation of 1280 m (Fig. 1, site 12). The curvature or torsion. There is a marked sulcus on the posterior side of the cave has multiple rooms and passageways on several levels, and contains horn core, which extends from the base of the horn core to the tip. The more than ten named late Pleistocene sites or sublocalities (Harris, 1970, distal-most half of the sulcus spirals very slightly toward the medial side 1985b). Harris (1985b) divided these sites into two general groups based of the horn core, but the horn core itself does not appear twisted. About on their vertebrate faunas and ages. The oldest sites, with radiocarbon half way along its course, a smaller sulcus appears to branch off from the ages ranging from approximately 25-34 ka, include Lost Valley, Room of lateral side of the main sulcus, extending about 30 mm towards the tip, the Vanishing Floor, and Sabertooth Camel Maze. The younger sites, diverging laterally slightly, but remaining about 3 mm from the main ranging from approximately 10-15 ka, include Animal Fair, pit N and W sulcus at its farthest separation. Other groves, much less well-defined, of Animal Fair, Hampton Court, Human Corridor, Stalag 17, and TT II. shorter and shallower, occur on the horn core, particularly on the anterior Harris (1993) identified Capromeryx sp. from the nine sites within the edge, 180 degrees from the main sulcus. All appear to begin just below Dry Cave system listed above. There are a half dozen or so additional the point where the prong is widest, which may mark the point where sites from Dry Cave that lack Capromeryx. Besides Capromeryx, five the skin normally ended, and the horn sheath began. Webb (1973, p. 208) other members of the extinct Pleistocene megafauna occur in both the describes the following for Hexameryx: “The base of each horn sheath is mid and late Wisconsinan sites in Dry Cave, Nothrotheriops shastensis, indicated by a ring of nutritive foramina and short sulci a few millimeters Equus occidentalis, Camelops hesternus, Hemiauchenia macrocephala, above the base of each horn core.” These are not present on the Tramperos and Stockoceros conklingi. Canis dirus, the tapir Tapirus sp., and Creek specimen; in fact we have been unable to identify such a feature in  645 FIGURE 3. NMMNH 50387, Capromeryx furcifer from Tramperos Creek Local Fauna, Union County, New Mexico. Partial skull in A, E, posterior views, B anterior view, C, right lateral view and D, left lateral view. 646 any fossil antilocaprine. Where such a feature appears to be present, it is named for specimens of Capromeryx of Rancholabrean, and perhaps due to the erosion, mechanical or otherwise, of the surface of the horn Irvingtonian, age, all of which have reduced anterior prongs. The trend core exposing the underlying spongy bone which tends to have struc- towards reduction of the anterior prong of Capromeryx begins with the tures paralleling the axis of the horn core. We have seen this on locations Blancan species C. tautonensis and C. arizonensis, as noted by Morgan along horn cores ranging from the base to the tips. and Morgan (1995). The trend continues in the surely Rancholabrean The anterior prong of each horn core is a tiny nubbin of bone species (C. furcifer, C. minor, C. mexicana). Capromeryx horn cores about 2.5 (left) or 3.0 mm (right) in height. It sits on a slight, flange-like from the Slaton Quarry in Texas, which were described as Capromeryx anterior expansion of the horn core base. minimus by Meade (1942), also show much reduced anterior prongs on Given the preserved portions of the skull, it is difficult to deter- the horn cores. However, their dating is not certain. Womochel, in an mine accurately the angle which the horn core follows in comparison to unpublished dissertation, placed the age of the Slaton Quarry Fauna as the long axis of the skull, usually determined by the basicranium, or by late Yarmouthian interglacial stage (Womochel, 1977, p. 134-137). This the occlusal plane of the dentition. Our best estimation for the present would place the fauna sometime just prior to about 0.6 Ma, and firmly in specimen is that the horn core, as determined primarily by the posterior the Irvingtonian NALMA (Bell, et al., 2004). The type of C. furcifer has prong, angles slightly anteriorly. We estimate this angle at between 10 been considered to be Irvingtonian as well, but deposits and fossils of and 15 degrees from a vertical line orthogonal to the occlusal plane of the Rancholabrean age are also known from the Hay Springs area, and early dentition. We note here that the basicranial plane and the occlusal plane collections do not have precise stratigraphic placement. If the type of C. of Capromeryx are not parallel to each other; in an as yet undescribed furcifer and the subsequently referred horn cores from Hay Springs are in skull (USNM 521305) from Muskox Cave, Eddy County, New Mexico, fact Irvingtonian, they likely date to the latter part of that NALMA in the occlusal plane dips anteriorly from the basicranial plane approxi- the “Sheridanian” subage (Bell et al., 2004, p. 274). A Capromeryx horn mately 10 degrees. core is known from the Noye’s Prospect site in the San Pedro Valley, Viewed posteriorly, the long posterior prongs of the horn cores do Arizona, sequence described by Johnson et al. (1975). This horn core, not diverge from each other, but appear to be parallel, and also parallel to UALP 14790 (Fig. 5B), which is intermediate both in overall size and in the sagittal plane. the reduction of the anterior horn core between C. arizonensis and known The posterior border of the base of the posterior prong describes Rancholabrean C. furcifer, is found in sediments above the upper bound- a line which passes just behind the posterior edge of the orbit. The ary of the Olduvai event and below the lower boundary of the Brunhes, anterior prong sits over the orbit at a point midway along the anterior and so dates to between 1.21 and 1.77 Ma (Bell, et al. 2004). This would half of the orbit. The posterior prong in this individual is gracile, long and have been considered to be within the Irvingtonian prior to the publica- gently tapering to the tip. Some specimens of Capromeryx such as LACM tion of Bell et al. (2004); the Blancan/Irvingtonian boundary is now 49, from Rancho La Brea (Chandler, 1916; see Fig. 5F), appear shorter, placed at the first well-dated occurrence of Mammuthus in New Mexico more robust and have an inflated appearance with the widest part of the at 1.3 Ma (Morgan and Lucas, 2003). While this makes the Noye’s posterior prong well distal to the base. Others, such as LACM 8523, Prospect locality Late Blancan, it then becomes the latest securely dated also from Rancho La Brea (Furlong, 1946; see Fig. 5E) appear much more Blancan occurrence of Capromeryx, and its intermediate size and mor- similar to the Tramperos Creek specimen. Our specimen also has a very phology are still relevant. straight posterior prong, quite unlike the gently curved posterior prong PALEOBIOLOGY on the type of Capromeryx minor (UCMP 26648) from Mexico as illustrated by Furlong (1925). However, there is a slight bend in the In the case of Capromeryx, there has been little discussion in the posterior prong about one quarter of the way distal to the base, but it is literature about possible sexual dimorphism in horn cores. However, in a sharply angled and not gently curved as in other specimens. subsequently overlooked comment, Chandler (1916, p. 112) describes a The parietals and frontals have a strongly defined ridge that forms specimen, UCMP (?) 21445, as the skull roof from the nasals to the a parasagittal crest, extending from the lateral base of the horn core in an occipital ridge, which shows a “…very minute tubercle which, by anal- S-shaped curve backward and inward to meet a similar ridge at the edge of ogy with Antilocapra, represents a rudimentary horn-core of a female the occipital. The surface of the frontal and parietal bones posterior to a animal…” We have not been able to locate this specimen in the UCMP line connecting the posterior-most extension of the base of the horn core collections; that catalog number is now associated with an incomplete has a distinctly roughened or pebbly appearance. This same surface dentary of Bison from Rancho La Brea. This is the only claimed instance topography appears in specimens of Capromeryx arizonensis from Florida of a female Capromeryx which we have found in the literature or seen in in the UF collections (RSW, personal observation). any collection. If Chandler (1916) is correct that the specimen represents There is a small pit approximately one centimeter in diameter a female individual, and if the specimen he referred to can be located, then lateral and slightly anterior to the base of the posterior prong of the horn the variation seen in the large horn cores is more likely geographical or core. This shallow pit does not connect with either of the two major sulci ontogenetic variation rather than sexual dimorphism. For the present, on the horn core. A similar pit is present on other specimens of then, we consider all horn cores of Capromeryx to represent male indi- Capromeryx, including the Blancan species C. arizonensis, complete viduals. enough to be evaluated. It does not occur on specimens of Tetrameryx We have already commented on the fact that Rancholabrean shuleri, on the paratype of Ceratomeryx prenticei, or on skulls of Capromeryx in New Mexico, while occurring over a wide area (and of Stockoceros. In Antilocapra americana, the supraorbital foramen occu- course the same is true beyond New Mexico) never occurs in significant pies the same approximate position as does the pit on Capromeryx; in numbers at any one site. This can be contrasted with a close Pleistocene other genera (Tetrameryx, Stockoceros, Ceratomeryx) the supraorbital relative, Stockoceros, and with the living pronghorn (Antilocapra foramen is in a more anterior position, forward of the horn cores. A americana). Stockoceros in particular is known from very large samples shallow pit medial and slightly anterior to the posterior prong of the horn from two caves, Papago Springs Cave (60+ individuals) in Arizona core appears to be an apomorphy of Capromeryx, but awaits a more (Roosevelt and Burden, 1934; Skinner, 1942; Czaplewski et al., 1999) extensive character analysis of the antilocaprinae. and San Josecito Cave (50+ individuals) in Mexico (Furlong, 1943). In Taxonomic assignment: We here consider all Capromeryx with neither case is there evidence on the bones that the materials were accu- anterior horn core prongs less than 50% of the length of the posterior mulated by predators. In Papago Springs, at least, there were a number of prong to belong to a single species, Capromeryx furcifer (Matthew, articulated skeletons. In addition, a Pleistocene accumulation of 1924). We follow this taxonomy for the present paper as a convenience Antilocapra americana is known from Natural Trap Cave in Wyoming pending a formal revision of the genus. Several other species have been (Chorn et al., 1988). In the case of Natural Trap Cave, the animals appear  647 FIGURE 4. Suggested reconstructions of the horn sheath of Capromeryx furcifer from Tramperos Creek. to have entered the cave through a deadfall entrance. This does not seem hook, which may reflect the presence of a bifurcate horn core with an to have been the case in either Papago Springs or San Josecito Cave, anterior prong in the ancestor of the modern pronghorn, which is now which both had entrances in the Pleistocene easily negotiable by prong- completely suppressed. We have prepared a series of possible recon- horn. There has been much discussion of the fact that only horned indi- structions of the horn of the Tramperos Creek Capromeryx (Fig. 4). We viduals seem to be represented in the case of Stockoceros; Skinner specu- have no way to evaluate which is the most likely reconstruction. On no lated that either both sexes had horns of approximately the same size, or basis other than a sort of energetic parsimony, we prefer the reconstruc- that only males congregated in Papago Springs Cave, perhaps due to tion shown in Figure 4A. seasonal aggregation of male-only herds, while the females and young Why the anterior horn core should have undergone reduction from avoided the caves. Skinner felt that the evidence from Papago Springs the early Blancan form, where both prongs of the horn core appear to Cave “strongly indicates that both sexes were well horned” (Skinner, have been robust and nearly the same size, to the Rancholabrean forms, 1942, p. 201). Yet, in the same paragraph he notes that it is not improb- culminating in the Tramperos Creek specimen in which the anterior horn able that “the cave collection represents a seasonal phenomenon, in core is vestigial and may not have been expressed in the horn sheath at all, which only males frequented the locality” (Skinner, 1942, p. 201). In is an even more difficult question to answer. One possible interpretation any case, a preliminary attempt by the senior author to correlate either relies on a comparison of horn and antler form among living bovids and the size or morphology of the horn cores with ontogenetic age of the cervids. skulls from Papago Springs and San Josecito caves has not been success- Jarman (1974) investigated the relationship between the ecology ful. and social organization of the diverse array of African antelopes. He Given the well documented gradual reduction of the anterior horn examined feeding strategies, including the nature of the plant communi- core of Capromeryx beginning in the early Blancan, and culminating with ties that the antelopes inhabit, body size, group size, sexual dimorphism the extreme degree of reduction documented by the Tramperos Creek and predator avoidance behavior. Jarman (1974) classified the African specimen described here, several hypotheses about what the animal may antelopes into five categories (Classes A, B, C, D and E), each with have looked like in life suggest themselves. It seems logical to reconstruct distinctly different ecological, behavioral and social characteristics. Table the horn core as a close-fitting covering of the bony horn core, but 2 presents a summary of the characteristics of Jarman’s five classes. It is alternative hypotheses are possible. The example provided by the mod- important to note that the descriptions in Table 2 are modal in nature; ern pronghorn, Antilocapra americana, the sole survivor of a once di- there is overlap between the classes in each category, sometimes signifi- verse lineage, is enough to urge caution in such reconstructions. Antilocapra cantly so. This attempt to apply Jarman’s classification, developed only americana has a single blade-like horn core, thick posteriorly and taper- to describe African antelopes, to antilocaprids is a preliminary effort. ing anteriorly. The sheath which covers it, however, has a forward-facing Jarman’s scheme ought to be tested more fully, for example, against living 648 TABLE 2. Summary of Class schema for African antelopes from Jarman (1974). Notes: * The oribi, at 9-20 kg is an outlier; the next smallest Class B species is the Vaal Rhebok at 23 kg. ** The number of unambiguously assigned species; those which were indicated as fitting more than one category (B/C/D, for example) were not included in this summary. cervids to see if his Classes have a more general utility. Nevertheless, over the landscape, moving centimeters to meters between bites. since we are using it here only to suggest possible interpretations of the Species in Class A “live singly, or in pairs, sometimes accompa- paleobiology of Capromeryx which can then be tested against other data, nied by a recent offspring. Thus, the group size varies from one to three, we believe the exercise to be worthwhile. is most commonly two, and does not vary seasonally” (Jarman, 1974, p. Jarman (1974) started with basic ecological, behavioral and social 232). This near solitary existence, and the lack of seasonal aggregations, characteristics as the basis for his classification and then noted that many would explain the widespread occurrence of Capromeryx, with very few physically observable characteristics, such as body size, sexual dimor- individuals at any one site. This contrasts strongly with Stockoceros, phism, and complexity of horns, could be correlated with his five catego- where large assemblages of fossils are known from cave sites, suggesting ries. In the present instance, we have attempted to fit Capromeryx into that Stockoceros may have been a Class C or D species, in which large one of his categories, and then use that to construct a hypothesis con- seasonal aggregations are typical. cerning the feeding ecology, behavior and social organization for this Jarman’s Class A predicts that Capromeryx would have relied on extinct antilocaprid. hiding as its primary anti-predator behavior. If it was diurnal, it likely fed The Tramperos Creek Capromeryx fits quite readily into Jarman’s in or near cover. “In the presence of predators, they either freeze, lie Class A. It is a relatively small animal, with a body size estimated at 10- down and freeze, or run to cover and freeze” (Jarman, 1974, p. 235). 13 kilograms (Saysette, 1999). The adult postcranial skeleton does not Because of their small size, they cannot outrun predators, nor can they exhibit marked sexual dimorphism (based on measurements of the discourage predator attacks with aggressive displays. Maintaining a soli- Capromeryx material by RSW at the Page Museum), which is also a tary, or very small group existence, minimizes the potential for a preda- characteristic of Jarman’s (1974) Class A. The horns (or at least the horn tor or group of predators to feed leisurely on a herd which could neither cores) of Capromeryx are simple and relatively small, again consonant outrun them nor defend itself by grouping. Maintaining the distance with Class A. If we then hypothesize, based on these physically observ- between animals is facilitated in Class A species by their strong territori- able characteristics, that Capromeryx would have been a Class A taxon, ality, which likely characterized Capromeryx as well. what predictions might provide into the ecology, behavior and social Finally, Jarman’s data can suggest that there was little dimor- structure of Late Rancholabrean Capromeryx, or on the evolution of phism in body size between males and females; furthermore, if there was Capromeryx through the Plio-Pleistocene? any difference, females may have been slightly heavier than males. Class Class A species tend to “feed very selectively on a wide range of A species males vary from 84% to 105% of the weight of conspecific plant species, using particular plant parts only, remaining in one vegeta- females (Jarman, 1974, p. 260). Jarman’s data show that for the ante- tion type and in one small home range throughout the year. These species lopes, only the males are horned in Class A. This is consonant with other are predominantly browsers….” (Jarman, 1974, p. 222). This prediction data mentioned before which indicates that female Capromeryx were provides an opportunity for testing through analysis of the dentition and essentially hornless, although small bosses on the frontal bone mark the isotopic signatures recorded in the bones and teeth. Capromeryx, under location of the horn cores that develop in the males. this model, would have selected one feeding habitat vegetation type, and In the case of the bovids described by Jarman (1974), and in the would have selected specific parts of the plants it encountered, rather case of cervids, as described by Geist (1998), the most ornate and largest than consuming entire plants. Individuals would have moved widely cranial appendages (not forked in bovids and generally forked in cervids)  649 FIGURE 5. Sequence of Capromeryx horn cores from late Blancan through Rancholabrean time. Blancan: A, AMNH 141172, Dry Mountain, Arizona, 2.32 ma; B, UA 14790, Noyes Prospect, Arizona 1.78 ma. Irvingtonian: C, TTU P-19, Slaton Quarry, Texas; D, TTU-P20, Slaton Quarry, Texas. Rancholabrean: E, LACM 8523, Rancho La Brea, California; F, LACM 49, Rancho La Brea, California; G, NMMNH 50387, Tramperos Creek, New Mexico. 650 correlate with the large size, open landscapes, large social groups and Jarman Class those earlier species might best occupy, it should be the sexual dominance hierarchies. Complexly forked antlers, or strongly or- goal of future research to examine this problem. The determination of namented horns (showing annular ridges, spiral form, or extreme size) are diet from dental wear and isotopic studies, along with the eventual loca- used primarily as display ornamentation, although they are also used as tion of larger samples amenable to analysis of potential dimorphism, sparring weapons specifically designed to minimize fatal injury to both should allow answers to these questions to be developed. combatants. Conversely, simple, relatively short single horns or simple Capromeryx may have been adapting to changing climatic condi- antlers correlate with a solitary life history, small size, and closed habitat tions by gradually adopting a solitary, less open habitat lifestyle. When (primarily forests). In these species, the horns and antlers are used as adequate samples of teeth from all the species of Capromeryx are avail- weapons for protection against predators or the protection of territories able for dietary analysis, it will be possible to test this interpretation by from conspecifics. determining if the dietary regime changed from a grazing, grass-domi- Comparison with Jarman’s classification as outlined above indi- nated diet to a diet more centered on leafy browse. cate that Capromeryx in the Rancholabrean were solitary, widely dis- persed animals which did not form seasonal aggregations. Males and AKNOWLEDGEMENTS females were roughly the same size in terms of body weight. The animals We wish to thank the reviewers of this paper, Greg McDonald, did not rely on either speed or aggression to avoid predators, but froze Edward Davis and Brian Beatty, for their careful attention to detail, logic and hid, suggesting that they were rather plainly marked, perhaps with and clarity of expression. Greg’s suggestion to include a more detailed dappling or other camouflage to break up their outline. Finally, they were summary of Jarman’s classificatory scheme greatly improved the utility likely territorial, with the males defending their territory against other of this paper. John-Paul Hodnett provided the drawings used in Figs. 3- animals of either sex. 5. E.H. Lindsay at the University of Arizona and S. Chatterjee at Texas Jarman’s data suggest one other hypothesis. Morgan and Morgan Tech University authorized the loan and study of critical specimens (1995) and a number of others after them, have noted the trend in size illustrated in this paper. We here recognize the valuable contribution of reduction which Capromeryx underwent, beginning in the Pliocene and Ken Garrison who discovered the Tramperos Creek site and found the culminating in the Rancholabrean with the tiny Capromeryx furcifer of specimen of Capromeryx from this locality. We also thank Mark Gor- Mexico and the American West. Capromeryx tautonensis and C. don, Rachael Montenegro, and Arden and John Montgomery for their arizonensis may have exhibited feeding strategies, social organization help at Tramperos Creek. RSW thanks Jan Saysette for years of discus- and anti-predator behaviors different from the terminal member of their sion of all things Capromeryx. lineage, C. furcifer. While the data are not yet available to evaluate which REFERENCES Bell, C.J., Lundelius, E.L., Barnosky, A.D., Graham, R.W., Lindsay, E.H., Harris, A.H., 1970, The Dry Cave mammalian fauna and late pluvial condi- Ruez, D.R., Semken, H.A., Webb, S.D. and Zakrzewski, R.J., 2004, The tions in southeastern New Mexico: Texas Journal of Science, v. 22, p. 3- Blancan, Irvingtonian and Rancholabran Mammal Ages; in Woodburne, 27. M.O., ed., Late Cretaceous and Cenozoic Mammals of North America: Harris, A.H., 1985a, Preliminary report on the vertebrate fauna of U Bar New York, Columbia University Press, p. 232-414 Cave, Hidalgo County, New Mexico: New Mexico Geology, v. 7, p. 74- Bryan, W.A., 1929, The recent bone-cavern find at Bishop's Cap, New 77, 84. Mexico: Science, v. 70, p. 39-41. Harris, A.H., 1985b, Late Pleistocene vertebrate paleoecology of the West: Chandler, A.C., 1916, Notes on Capromeryx material from the Pleistocene Austin, University of Texas Press, 293 p. of Rancho La Brea: University of California Publications, Bulletin of Harris, A.H., 1993, Quaternary vertebrates of New Mexico: New Mexico the Department of Geology, v. 9, p. 111-120. Museum of Natural History and Science, Bulletin 2, p. 179-197. Chorn, J., Frase, B.A. and Frailey, C.D., 1988, Late Pleistocene pronghorn, Harris, A.H., 2003, The Pleistocene vertebrate fauna from Pendejo Cave; Antilocapra americana, from Natural Trap Cave, Wyoming: Transac- in MacNeish, R.S and Libby, J.G., eds., Pendejo Cave: Albuquerque, Uni- tions of the Nebraska Academy of Sciences, v. 15, p. 127-139. versity of New Mexico Press, p. 36-65. Conkling, R.P., 1932, Conkling Cavern: the discoveries in the bone cave at Harris, A.H., 2011, Pleistocene vertebrates of New Mexico and Trans- Bishops Cap, New Mexico: West Texas Historical and Scientific Society, Pecos Texas: Website hosted by the Laboratory for Environmental Bulletin 44, p. 39-41. Biology at the University of Texas at El Paso, http://www.utep.edu/leb/ Cosgrove, C.B., 1947, Caves of the Upper Gila and Hueco areas in New pleistNM/default.htm. Mexico and Texas: Papers of the Peabody Museum of American Archae- Haynes, C.V., 1995, Geochronology of paleoenvironmental change, Clovis ology and Ethnology, Harvard University, v. 24, p. 1-182. type site, Blackwater Draw, New Mexico: Geoarchaeology, v. 10, p. Czaplewski, N.J., Mead, J.I., Bell, C.J., Peachy, W.D. and Ku, T.L., 1999, 317-388. Papago Springs Cave revisited, Part II: vertebrate paleofauna: Occa- Haynes, C.V., Jr. and Agogino, G.A., 1986, Geochronology of Sandia Cave: sional Papers of the Oklahoma Museum of Natural History, no. 4, p. 1- Smithsonian Contributions to Anthropology, v. 32, p. 1-32. 25. Hester, J.J., ed., 1972, Blackwater Draw Locality No. 1. A stratified, early Degenhardt, W.G., Painter, C.W. and Price, A.H., 1996, Amphibians and man site in eastern New Mexico: Fort Burgwin Research Center, South- reptiles of New Mexico: Albuquerque, University of New Mexico Press, ern Methodist University, Publication no. 8, 239 p. 431 p. Hibben, F.C., 1941, Evidences of early occupation in Sandia Cave, New Furlong, E.L., 1925, Notes on the occurrence of mammalian remains in the Mexico, and other sites in the Sandia-Manzano region: Smithsonian Pleistocene of Mexico, with a description of a new species Capromeryx Miscellaneous Collections, v. 99, no. 23, p. 1-44. mexicana: University of California Publications in Geological Sciences, Holliday, V.T., 1997, Paleoindian geoarchaeology of the Southern High v. 15, p. 137-152. Plains: Austin, University of Texas Press, 297 p. Furlong, E.L., 1946, Generic identification of the Pleistocene antelope Holliday, V.T., 2005, Ice-Age peopling of New Mexico: New Mexico Mu- from Rancho La Brea: Carnegie Institution of Washington, Publication seum of Natural History and Science, Bulletin 28, p. 263-276. 551, p. 135-140. Jarman, P.J., 1974, The social organization of antelope in relation to their Geist, V., 1998, Deer of the world: their evolution, behavior and ecology: ecology: Behaviour, v. 48, p. 215-267. Mechanicsburg, Stackpole Books, 421 p. Johnson, N.M., Opdyke, N.D. and Lindsay, E.H., 1975, Magnetic polarity  651 stratigraphy of Pliocene-Pleistocene terrestrial deposits and vertebrate Slaughter Canyon Cave: New Mexico Geological Society, Guidebook 57, faunas, San Pedro Valley, Arizona: Geological Society of America, Bulle- p. 23-24. tin 86, p. 5-12. Roosevelt, Q. and Burden, J.W., 1934, A new species of antilocaprine, Lawrence, B., 1960, Fossil Tadarida from New Mexico: Journal of Mam- Tetrameryx onusrosagris, from a Pleistocene cave deposit in Southern malogy, v. 41, p. 320-322. Arizona: American Museum Novitates, no. 754, p. 1-4. Logan, L.E., The mammalian fossils of Muskox Cave, Eddy County, New Saysette, J.E., 1999, Postcranial estimators of body mass in pecorans with Mexico: Proceedings of the Eighth International Congress of Speleol- emphasis on Capromeryx (Mammalia: Artiodactyla) [Ph.D. disserta- ogy, v. I and II, p. 159-160. tion]: Colorado State University, 192 p. Lundberg, J. and McFarlane, D.A., 2006, A minimum age for canyon inci- Schumacher, B.A., 2001, A new Late Neogene paleo-fauna from the Kiowa/ sion and for the extinct molossid bat, Tadarida constantinei, from Carlsbad Rita Blanca National Grassland, northeastern New Mexico: New Mexico Caverns National Park, New Mexico: Journal of Cave and Karst Studies, Geological Society, Guidebook 52, p. 293-295. v. 68, p. 115-117. Skinner, M.F., 1942, The fauna of Papago Springs Cave, Arizona and a Lundelius, E.L., Jr., 1972, Vertebrate remains from the Gray Sand; in Hester, study of Stockoceros with three new antilocprines from Nebraska and J.J., ed., Blackwater Draw Locality No. 1. A stratified early man site in Arizona: Bulletin of the American Museum of Natural History, v. 80, p. eastern New Mexico: Fort Burgwin Research Center, Southern Method- 143-220. ist University, Publication no. 8, p. 148-163. Slaughter, B.H., 1975, Ecological interpretation of the Brown Sand Wedge Meade, G.E., 1942, A new species of Capromeryx from the Pleistocene of local fauna; in Wendorf, F. and Hester, J.J., eds., Late Pleistocene envi- west Texas: Bulletin of the Texas Archeological and Paleontological ronments of the Southern High Plains: Dallas, Fort Burgwin Research Society, v. 14, p. 88-96. Center, Southern Methodist University, Publication no. 9, p. 179-192. Morgan, G.S., 2002, Pleistocene vertebrate fossils from Slaughter Canyon Stock, C., 1930, Quaternary antelope remains from a second cave deposit Cave, Carlsbad Caverns National Park: Park Paleontology, v. 6, p. 5. in the Organ Mountains, New Mexico: Los Angeles Museum, Science Morgan, G.S. and Lucas, S.G., 2003, Mammalian biochronology of Blancan Series, Paleontology, no. 2, p. 1-18. and Irvingtonian (Pliocene and early Pleistocene) faunas from New Stock, C., 1932, A further study of the Quaternary antelopes of Shelter Mexico: Bulletin of the American Museum of Natural History, no. 278, Cave, New Mexico: Los Angeles Museum, Science Series, Paleontology, p. 269-320. no. 3, p. 1-45. Morgan, G.S. and Lucas, S.G., 2005, Pleistocene vertebrate faunas in New Thompson, J.C. and Morgan, G.S., 2001, Late Pleistocene mammalian Mexico from alluvial, fluvial, and lacustrine deposits: New Mexico Mu- fauna and environments of the Sandia Mountains, New Mexico: Current seum of Natural History and Science, Bulletin 28, p. 185-248. Research in the Pleistocene, v. 18, p. 113-115. Morgan, G.S. and Lucas, S.G., 2006, Pleistocene vertebrates from south- Thompson, J.C., Sugiyama, N. and Morgan, G.S., 2008, Taphonomic analy- eastern New Mexico: New Mexico Geological Society, Guidebook 57, p. sis of the mammalian fauna from Sandia Cave, New Mexico, and the 317-335. “Sandia Man” controversy: American Antiquity, v. 73, p. 337-360. Morgan, G.S., Lucas, S.G., Sealey, P.L. and Hunt, A.P., 2001, A review of Thompson, R.C, Van Devender, T.R., Martin, P.S., Foppe, T and Long, A, Pleistocene vertebrate faunas from northeastern New Mexico: New 1980, Shasta ground sloth (Nothrotheriops shastense Hoffstetter) at Mexico Geological Society, Guidebook 52, p. 265-284. Shelter Cave, New Mexico: environment, diet, and extinction: Quater- Morgan, J.K. and Morgan, N.H., 1995, A new species of Capromeryx (Mam- nary Research, v. 14, p. 360-376. malia: Artiodactyla) from the Tauton Local Fauna of Washington, and Webb, S.D., 1973, Pliocene pronghorns of Florida: Journal of Mammalogy, the correlation with other faunas of Washington and Idaho: Journal of v. 54, p. 203-221. Vertebrate Paleontology, v. 15, p. 160-170. Womochel, D.R., 1977, Taphonomy and paleoecology of the Slaton Local Polyak, V.J., Asmerom, Y. and Rasmussen, J.B.T., 2006, Old bat guano in Fauna (Pleistocene, Texas) [Ph.D. dissertation]: Lubbock, Texas Tech University, 148 p.