Pseudaelurus sp.

Smith, Kent, Czaplewski, Nicholas & Cifelli, Richard L., 2016, Middle Miocene carnivorans from the Monarch Mill Formation, Nevada, Acta Palaeontologica Polonica 61 (1), pp. 231-252 : 246-247

Pseudaelurus sp.

Fig. 8 .

Material.—UCMP 141531, partial left dentary with anterior root of p3 and partial p4, from UCMP V70138 (OMNH V967), Eastgate, Churchill County, Nevada, USA; Monarch Mill Formation, Barstovian (Miocene).

Measurements.—See Table 4.

Description.— Dentary: UCMP 141531 is a dentary fragment with a fragment of the p3 (anterior cingular cusp and anterior root only), p4 (lacking main cusp) and root-filled alveoli for the m1. The dentary fragment is short and stout and is fractured in two places: anterior to the anterior root of p3 and posterior to the posterior root of m1. The anterior part of the masseteric fossa is preserved and terminates below the posterior root of the m1. On the lateral aspect of the dentary are two mental foramina, one below the anterior root of p3 and the second below the posterior root of the p3.

Lower teeth: The p4 has distinct anterior and posterior cingular cusps, and a distinct posterior accessory cusp. The principal cusp of p4 is broken off near its base, level with the apex of the accessory cusp.

Remarks.— Rothwell (2003) recognized five species of Pseudaelurus ( P. validus Rothwell, 2001 , P. skinneri Rothwell, 2003 , P. intrepidus Leidy, 1858 , P. marshi Thorpe, 1922 , and P. stouti [ Schultz and Martin, 1972]) from the Barstovian of North America. Although Rothwell (2003) did not synonymize P. aeluroides Macdonald, 1954 with P. marshi , he suggested that the two species are likely synonymous because of similar size and characteristics described by Macdonald (1954). Rothwell (2003: 12) provided a generic diagnosis for Pseudaelurus , but none of the diagnostic derived characters is preserved in the Eastgate fossil. Similarly, in the diagnoses for individual species within the genus, relevant diagnostic characters are not preserved in the Eastgate fossil, with one exception. One species, P. skinneri , lacks prominent anterior cingular cusps on p3 and p4 whereas most species of Pseudaelurus possess these cusps. The Eastgate specimen possesses anterior cingular cusps (although not particularly prominent ones) on p3 and p4, and thus probably does not represent P. skinneri . In Rothwell’s (2003) phylogenetic analysis of Pseudaelurus species, 23 characters were examined. Of these, 13 are based on the dentition, but none of these characters are well preserved in the Eastgate felid. Rothwell’s (2003) only phylogenetic character pertaining to the p3 and p4 is his character 4, in which p3 and p4 heights are similar in P. stouti , while p3 is considerably smaller than p 4 in all other North American Pseudaelurus species. The p 3 in the Eastgate dentary is mostly missing; thus, the relative heights of p3 and p4 cannot be compared. The relative sizes, as reflected in length of the c–p3 and length of m1, were used as well by Rothwell (2003) in part to differentiate among the species of Pseudaelurus (see Table 4). Unfortunately, these characteristics also are missing in UCMP 141531 from Eastgate, so that no measurements can be directly compared with any of the species. However, the Eastgate specimen is relatively small, suggesting that it might represent one of the smaller species of Pseudaelurus .

Figures

Fig. 8. Felid carnivoran Pseudaelurus sp. from the Eastgate LF, basal-most unit of the Monarch Mill Formation, Barstovian (Miocene), Churchill County, Nevada, USA. UCMP 141531, partial left dentary with anterior root of p3 and partial p4, in lingual (A), occlusal (B), and labial (C) views.