2009 Portland GSA Annual Meeting (18-21 October 2009)
Paper No. 172-14
Presentation Time: 9:00 AM-6:00 PM

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

KOTTACHCHI, Niranjala1, CANCHOLA, Joe A.1, and DUNDAS, Robert G.2, (1) Department of Earth and Environmental Sciences, California State University, Fresno, CA 93740, joecanchola@csufresno.edu, (2) Department of Earth & Environmental Sciences, California State University, Fresno, CA 93740

The Fairmead Landfill locality in Madera County is the largest middle Pleistocene (late Irvingtonian) biota in the San Joaquin Valley of California. The site has produced 51 taxa from 40 acres since its discovery in May 1993. Fossils are preserved in the upper unit of the Turlock Lake Formation. This study identifies several peccary specimens from the site; an associated forelimb and dentition (MCPC A321), a dentary fragment with an unworn tooth (MCPC A322), and a tooth fragment displaying two angular, high crowned cusps (MCPC A323).

Specimen MCPC A321 consists of associated partial dentaries with teeth (left p2-m3 and right p3-m3) and a partial right forelimb 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. 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 36.35 mm and left molar row length is 59.8 mm. Right premolar row length, lacking the p2, is 24.6 mm and right molar row length is 59.5 mm. Elements of the associated forelimb were also measured. Values obtained from both dentary and forelimb measurements indicate a relatively large species of peccary.

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 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 Pennsylvania (Ray et al. 1970), Laubach Cave in Texas (Slaughter 1966), and Cumberland Cave in Maryland (Gidley 1920). The Fairmead Landfill remains compare well with the large species Platygonus vetus and are therefore referred to Platygonus cf. P. vetus.

2009 Portland GSA Annual Meeting (18-21 October 2009)
General Information for this Meeting
Session No. 172--Booth# 104
Paleontology: Morphology, Systematics, & Education (Posters)
Oregon Convention Center: Hall A
9:00 AM-6:00 PM, Tuesday, 20 October 2009

Geological Society of America Abstracts with Programs, Vol. 41, No. 7, p. 453

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