Platygonus Cf. P. Vetus from the Middle Pleistocene (Late Irvingtonian) Fairmead Landfill Locality, Madera County, California

Home , Platygonus, Platygonus compressus

PLATYGONUS CF. P. VETUS FROM THE MIDDLE PLEISTOCENE (LATE IRVINGTONIAN) FAIRMEAD LANDFILL LOCALITY, MADERA COUNTY, CALIFORNIA

Niranjala Kottachchi, Joe A. Canchola and Robert G. Dundas, Department of Earth & Environmental Sciences, California State University, Fresno, California 93740 [email protected]

INTRODUCTION

The Fairmead Landfill locality in Madera County (Figures 1 and 2) is the largest middle Pleistocene (late p3 p4 m1 Irvingtonian) biota in the San Joaquin Valley of California. The site has produced 51 taxa from 40 acres p2 m2 m3 since its discovery in May 1993. Fossils are preserved in the upper unit of the Turlock Lake Formation.

This study identifies several peccary (Figure 3) specimens from the site; an associated forelimb and p2 dentition (MCPC A321) (Figures 4 and 7), a dentary fragment with an unworn tooth (MCPC A322), and a m1 tooth fragment displaying two angular, high crowned cusps (MCPC A323). Comparisons were made with m2 p4 p3 peccary specimens at the University of Florida and University of Texas at Austin (Figures 5 and 6). m3 m3 m2 Specimen MCPC A321 consists of associated partial dentaries with teeth (left p2-m3 and right p3-m3) and m1 p4 p3 a partial right forelimb (Figure 7), including a proximal scapula, humerus, radius-ulna, carpals, metacarpals III and IV, and proximal phalanx. Right and left cheek teeth display a high, angular, bilophodont structure. m3 m2 m1 p4 p3 p2 The premolars and m1-m2 on both sides of the mandible are heavily worn, particularly on the lingual side. Both pairs of cusps connected by transverse crests are distinct on the m2-m3 but are worn down on the m1. The right m3 displays a fifth cusp at the posterior end. Estimated left premolar row length is 35 mm and left molar row length is 59.1 mm. Right premolar row length, lacking the p2, is 24.2 mm and right Figure 5. Dentition of Platygonus cumberlandensis (UF 12090) from the University of Florida. molar row length is 59 mm. Elements of the associated forelimb were also measured (Table 1). Values obtained from both dentary and forelimb measurements indicate a relatively large species of peccary. Figure 4. Partial dentition (lower left and right) from Platygonus cf. P. vetus (MCPC Figure 6. Platygonus compressus mandible (TMM 41465-42) A321). from the University of Texas at Austin. Late Irvingtonian peccaries include Mylohyus nasutus, with molarized premolars and bunodont cheek teeth, and Platygonus vetus, with nonmolarized premolars and zygodont to zygolophodont cheek teeth. Based on dental and postcranial features, such as the presence of zygolophodont cheek teeth, the TAXONOMY 65 29 Fairmead Landfill peccary is Platygonus. The remains are large for Platygonus, exceeding the size of Platygonus compressus as described from northwestern New Mexico (Lucas & Smartt 1995), northern The taxonomy of Platygonus needs a thorough reevaluation as many of the descriptions have been Pennsylvania (Ray et al. 1970), Laubach Cave in Texas (Slaughter 1966), and Cumberland Cave in based on fragments, incomplete comparisons with other specimens, and very little attention given to intraspecific variation. Platygonus was first described in 1848 by LeConte and since then, several other Maryland (Gidley 1920). The Fairmead Landfill remains compare well with the large species Platygonus 60 27 vetus and are therefore referred to Platygonus cf. P. vetus. species have been described by other authors. Leidy (1882) first proposed P. vetus for upper and lower jaw fragments from Mifflin County, Pennsylvania. Other Pleistocene species of importance here include P. cumberlandensis Gidley 1920, P. intermedius Gidley 1920, and P. compressus LeConte 1848. Gidley

(1920) recognized P. vetus to be of significantly larger size than P. compressus. In addition, Gidley 55 25 (1920) examined specimens of P. cumberlandensis and P. intermedius from Cumberland Cave in Pennsylvania. Although nearly equating to the size of P. vetus, P. cumberlandensis had slightly smaller dentition (87-94 mm length for upper cheek-tooth rows) than P. vetus (97 mm) but larger than P. Length (mm) Length (mm) compressus in both dentition (74-80 mm) and skull size. Although displaying similar characteristics to P. 50 23 cumberlandensis, P. intermedius had larger dentition and a smaller skull. The zygoma below the orbit is much more developed in P. cumberlandensis and P. intermedius than P. compressus. Despite the variability noted above, Gidley & Gazin (1938) chose to synonomize P. cumberlandensis and P. MCPC A321 MCPC A321 P. cumberlandensis intermedius stating that their differences were insufficient to warrant separation (Slaughter, 1966). Kurtén 45 21 P. cumberlandensis & Anderson (1980) synonomised P. cumberlandensis and P. intermedius with P. vetus, but kept P. P. intermedius P. intermedius compressus independent from the other taxa due to differences in tooth row and skull size, and zygoma P. vetus P. vetus characteristics. P. compressus P. compressus 40 19 10 11 12 13 14 15 16 17 10 11 12 13 14 15 16 17

METHODOLOGY Width (mm) Width (mm) Length and width measurements of premolars and molars were taken on specimens of P. Figure 8. Length vs width measurements (m1 – m3) for MCPC A321 Figure 9. Length vs width measurements (m3) for MCPC A321 cumberlandensis and P. vetus from the University of Florida as well as from partial lower dentaries (Fairmead Landfill), P. cumberlandensis (measured at the University of (Fairmead Landfill), P. cumberlandensis (measured at the University of MCPC A321 from Fairmead Landfill. Values obtained from the molars were compared with Florida and from Gidley, 1920), P. intermedius (Gidley, 1920), P. vetus of Florida and from Gidley, 1920), P. intermedius (Gidley, 1920), P. published measurements of P. cumberlandensis and P. intermedius from Cumberland Cave, (measured at the University of Florida), and P. compressus (Williston, vetus (measured at the University of Florida and from Leidy, 1882), Maryland, and P. compressus from Mosherville, Pennsylvania, Laubach Cave, Texas, and Kansas 1894; Slaughter, 1966; Ray et al. 1970; and Finch et al. 1972). and P. compressus (Williston, 1894; Slaughter, 1966; Ray et al. 1970; (Figures 8, 9, and 10). Molar and premolar cusp and loph characteristics were also analyzed and and Finch et al. 1972). Figure 1. Location of the Fairmead Landfill 100 compared among the species. We also measured MCPC A321 postcrania and compared the locality (red star) in central California, values with those of P. compressus from Mosherville, Pennsylvania (Table 1). approximately 34 miles northwest of Fresno.

Fairmead Landfill, CA Mosherville, PA RESULTS AND CONCLUSIONS (MCPC A321) (USNM 23706) 90 Although plotted here as separate taxa for comparative purposes, we Scapula agree with Kurtén & Anderson (1980) in synonomizing P. Length ------cumberlandensis and P. intermedius with P. vetus. There is 85 Width ------88 considerable overlap in length measurements and a small overlap in Anterior-posterior diameter of glenoid surface 36 28.5

Transverse diameter of the same 29 25.8 Length (mm) width measurements of P. compressus with those of P. vetus, P. Least anteroposterior diameter of neck 29.4 21.8 cumberlandensis, and P. intermedius. However, length, and notably Greatest anteroposterior diameter distally, including 40 33.9 80 width measurements, of P. compressus molars never reach the values supraglenoidal tubercle seen in the largest samples of P. vetus. Some data included in MCPC A321 Figures 8, 9, and 10 are Laubach Cave specimens which are among Humerus P. cumberlandensis Length 217 195 75 the largest teeth measurements on record for P. compressus P. intermedius Length from head to posterior process of inner condyle 186 167 (Slaughter, 1966). Even with the absence of zygoma in the Fairmead Transverse diameter of proximal articular surface 45 35.4 P. vetus Landfill sample, which is important for distinguishing between these Maximum breadth near proximal end 56 47.5 P. compressus two species, the molar measurements of sample MCPC A321 fall at Anteroposterior diameter of shaft just below deltoid tubercle 40 33.8 70 Maximum breadth near distal end, across epicondyles ------39.8 10 11 12 13 14 15 16 17 the high end of the P. vetus range. Measurements of the elements of Maximum breadth of distal articulation ------28.8 Width (mm) the associated forelimb are substantially larger in comparison to the P. Figure 2. Aerial view of Fairmead Landfill facing west. Figure 10. Length vs width measurements (p2 - m3) for MCPC A321 compressus specimen of Mosherville, Pennsylvania (Table 1). Taken View is along eastern margin of landfill showing an Radius/Ulna (Fairmead Landfill), P. cumberlandensis (measured at the University of together, the dental and postcranial measurements of MCPC A321 excavation cell. Length of ulna 232 ------Florida and from Gidley, 1920), P. intermedius (Gidley, 1920), P. vetus support the Fairmead Landfill specimen’s assignment to P. cf. vetus. Length of radius 176 ------Width of sigmoid fossa ------27.7 (measured at the University of Florida), and P. compressus (Williston, Least width of conjoined bones 27 24.7 1894; Slaughter, 1966; Ray et al. 1970; and Finch et al. 1972). Greatest breadth of distal portion of conjoined bones 45 ------Greatest breadth of distal articular surface 44 ------REFERENCES Figure 7. Associated right forelimb of Dundas, R.G., Smith, R.B., and Verosub, K.L. 1996. The Fairmead Landfill Locality (Pleistocene, Irvingtonian), Madera County, California: preliminary report and significance. In The uses of Metacarpal III vertebrate fossils in biostratigraphic correlation, ed. C. J. Bell and S. S. Sumida. PaleoBios 17(2–4):50–58. Platygonus cf. P. vetus (MCPC A321 Length 100 ------from Fairmead Landfill). The elements Finch, W. I., Whitmore Jr., F. C., and Sims, J. D. 1972. Stratigraphy, morphology, and paleoecology of a fossil peccary herd from western Kentucky: United States Geological Survey Professional Paper 790, 25 p. appear above in the positions in which Metacarpal IV Gidley, J.W. 1920. Pleistocene peccaries from the Cumberland Cave deposit: Proceedings of the United States National Museum, v. 57 (2324), Washington, p. 651 – 678. they were discovered in the sediment. Length 103 82 Gidley, J.W. and Gazin, C.L. 1938. The Pleistocene vertebrate fauna from Cumberland Cave, Maryland. Bulletin of the United States National Museum, no. 171, 99 p. Harris, J. M. and G. T. Jefferson. 1985. Rancho La Brea: Treasures of the Tar Pits. Natural History Museum of Los Angeles County, Science Series 31. Proximal phalanx, digit III Johnston, C.S. 1935. An extension in the Range of Fossil Peccaries: The American Midland Naturalist, v. 16 (1), p. 117-119. Length 42 ------Kurtén, B. and Anderson, E. 1980. Pleistocene Mammals of North America: Columbia University Press, New York, 442 p. Leidy, J. 1882. On an extinct peccary. Proceedings of the Academy of Natural Sciences of Philadelphia, v. 34 (3), p. 301-302. Table 1. Measurements (mm) of postcranial elements (right forelimb) of Platygonus cf. P. Lucas, S.G. and Smartt, R.A. 1995. Late Pleistocene peccary from northwestern New Mexico: The Southwestern Naturalist, v. 40 (3), p. 293 – 296. vetus (MCPC A321) from Fairmead Landfill and Platygonus compressus from Lundelius, E.L. 1960. Mylohyus nasutus: long-nosed peccary of the Texas Pleistocene: Bulletin of the Texas Memorial Museum, number 1, Austin, 40 p. Figure 3. Reconstruction of Platygonus (Harris & Ray, C.E., Denny, C.S., and Rubin, M. 1970. A peccary, Platygonus compressus Leconte, from drift of Wisconsinan age in northern Pennsylvania: American Journal of Science, v. 268, p. 78-94. Mosherville, Pennsylvania (USNM 23706) (Ray et al. 1970). Simpson, G.G. 1949. A fossil deposit in a cave in St. Louis: American Museum of Natural History, New York, no. 1408, p. 1 – 46. Jefferson, 1985). Slaughter, B.H. 1966. Platygonus compressus and associated fauna from the Laubach Cave of Texas: The American Midland Naturalist, v. 75 (2), p. 475 – 494. Williston, S.W. 1894. Restoration of Platygonus. Kansas University Quarterly, v. 3, p. 23-29.