10 



University of California Publications in Geology [Vol. 13 



PLATYGONUS, possibly n. sp. or n. subsp. 

 Skull 



The skull, no. 4400, L. A. M. H. S. A., 1 from Rancho La Brea pos- 

 sesses the facial region including the palate and superior dentition. 

 The posterior portion of the specimen has suffered much loss, 

 but on the left side there remain structures around the orbit and 

 posterior to the glenoid fossa that furnish some information of this 

 region of the cranium. At the anterior end of the snout the nasals 

 are broken away. The teeth, with exception of M 1 and M-, show a 

 moderate degree of wear. M= and particularly M- are well worn, as 

 is also the anterior edge of the superior canine. 



Specimen 4400 is definitely referable to the genus Platygonus. The 

 diastema between superior canine and P- is not characterized by great 

 length as in Mylokyus, but is slightly longer than in Tayassu. It 

 reaches a length slightly greater than that of the premolar series. 

 Two incisors are present in each premaxillary, their alveoli indicating 

 that the forward or medial incisor was very large while the posterior 

 or lateral tooth, situated immediately behind the former, was much 

 smaller. P^ is not molariform. Although the cheek-tooth series has 

 been subjected to attrition, the cusps of the individual teeth seem to 

 •be characterized by a more prominent development than in teeth of 

 Tayassu. 



The specimen available from Rancho La Brea agrees fairly closely 

 in size with peccary skulls from the Pleistocene of Kansas described 

 by Williston 2 under the species Platygonus leptorhinus. It likewise 

 compares favorably in this character with skull specimens referred to 

 P. compressus. In no. 4400 a shallow fossa is present above and be- 

 hind the posterior margin of the exit of the infra-orbital canal, while 

 a deeper fossa is located in front of the opening. Fossae comparable 

 to these are noted by Williston in a female skull of P. leptorhinus, 

 but are lacking, according to Wagner, 3 in the skull of P. compressus 

 from the Pleistocene of Michigan. While the groove or sulcus that 

 extends along the lateral side of the snout is present in the California 

 skull, a continuation of the groove can not be traced to the top of the 

 skull because of the destruction of the greater portion of the dorsal 



i Los Angeles Museum of History, Science and Art, Los Angeles, Calif. 



- Williston, S. W., Eestoration of Platygonus. Kansas Univ. Quar., vol. 3, 

 pp. 23-39, pis. 7 and 8, 1894. 



3 Wagner, G., Observations on Platygonus compressus Le Conte. Jour. Geol., 

 vol. 11, pp. 777-782, figs. 1-4, 1903. 



