Dinofelis aronoki, Werdelin & Lewis, 2001

O’Regan, Hannah J. & Steininger, Christine, 2017, Felidae from Cooper’s Cave, South Africa (Mammalia: Carnivora), Geodiversitas 39 (2), pp. 315-332 : 322

cf. Dinofelis aronoki

MATERIAL EXAMINED. — Cranial. CD 1555, right anterior mandible fragment from symphysis to P 3 alveoli ( Table 2). CD 15660, two refitting I2 crown fragments.

Postcranial. CD 670, a damaged right MT 4 ( Table 3); CD 650, a right MT 4 shaft fragment; CD 3284, a 1 st phalanx; CD 1195, a dew claw 1st phalanx; CD 979, a 3rd phalange; CD 3881, a left distal tibia ( Table 3); CD 5674, a right unciform; CD 654, a right femoral head ( Table 3); CD 3712 + CD 5972, two refitting pieces of a right distal radius ( Table 3).

DESCRIPTION

CD 1555 is an edentulous right mandible fragment, with the lower portion of the symphysis present, retaining the alveoli of the I 3 and Ci, plus the complete diastema and both alveoli for the P 3. There is a small symphyseal bulge, but it is clearly not a flange with a near vertical ramus, as seen in Megantereon whitei from the same site (CD 5997; Fig. 5B ). There is a single, very large, mental foramen below the anterior root of the P 3. The inferior border of the mandible is straight. There is a distinct dip on the lingual surface of the ramus that is also seen in CD 18836 ( Dinofelis cf. aronoki ) and M607 ( D. darti from Makapansgat) and is much less pronounced in leopard. CD 15660 is a fragmentary I 2 in two pieces; it has a large central cusp and a pronounced accessory cusp, with a tiny worn extra cusplet between the two. It matches well with KA 61 ( Dinofelis piveteaui from Kromdraai A), although a slight ridge leads from the accessory cusp to the lingual surface, which is not as pronounced as that of KA 61.

Postcrania

CD 3712 and CD 5972. Two refitting right distal radius fragments. The bone is intermediate in size between lion and leopard, with a narrower articulation (anterior-posterior) than is seen in leopard. The ulnar facet is very large and placed slightly off-centre with strong ridges above it. It is similar to, but smaller, than DN 86 a Dinofelis specimen from Drimolen. However, the distal facet is more rectangular in the Coopers specimen and the ridge along the fusion line is not so distinct. It is therefore assigned to cf. Dinofelis .

CD 5674. Complete right unciform. It is not from a pantherine cat. It matches an unnumbered Dinofelis specimen from Makapansgat in size and in the length of the distal facet, although the anterior surface is a slightly different shape. It also matches KNM-ER 722I, Dinofelis piveteaui , illustrated in Werdelin & Lewis (2001: fig. 19). It is therefore assigned to Dinofelis .

CD 1195. Complete first dew claw phalanx, which appears to have been slightly gnawed. There are two clear and equally-sized lobes to the proximal articulation and has a distinct protuberance on the dorsal surface. In lion the proximal articulation is not so defined, and in Homotherium (as shown by Ballesio 1963) one facet is smaller than the other. It is most like an unnumbered Dinofelis sp. specimen from Makapansgat, and it has therefore been referred to that genus.

CD 654. Right proximal femoral head broken across the neck. The articulation continues onto the neck a little, a feature that is not seen in the extant cats, but is seen in Makapansgat Dinofelis specimen 16190M. The articulation also extends onto the neck in Megantereon whitei . However, the head is not as rounded in Megantereon Croizet & Jobert, 1828 KB 5333L as it is in CD 654, and it has therefore been assigned to Dinofelis . CD 3881 is a distal tibia, broken just above the articulation. The distal articulation is broader than that of the leopard, and the shaft of Megantereon is more triangular rather than squared as in this specimen. It is a good match for DN 2149a, Dinofelis from Drimolen, but it is from a smaller animal. CD 670 and CD 650 are Dinofelis -sized right 4 th metatarsals. CD 670 is almost complete, but the proximal articulation is large missing. CD 650 is a shaft fragment with the beginnings of the proximal articulation. Both are much more robust than leopard, and have similarities to DN 14 from Drimolen, however there are some slight differences in the position of the remaining facets, so they have been assigned to cf. Dinofelis aronoki . CD 3284 is a complete first phalanx, which is a good match for KB 6037 ( Dinofelis sp. ). It is slightly shorter than this specimen, but has a slightly flattened shaft and the same dip on the dorsal surface between the condyles. CD 979 is a large felid third phalanx. It is too small for Homotherium (if the unnumbered Makapansgat specimen is Homotherium , as suggested by Werdelin & Lewis [2001: 190]), and is a good size match for an unnumbered D. darti paw that is also from Makapansgat.

Figures

FIG. 5. — Craniodental felid specimens; A-D, Megantereon whitei (Broom, 1937); A, CD 5963, buccal view of right mandible; B, CD 5997, buccal view of left mandible; C, D, CD 10452 in buccal (C) and lingual (D) views of lower M; E, cf. Megantereon whitei, CD 10497, left upper I3 with two cusplets on medial surface; 1 F, G, Machairodontinae indet.,CD 3835,right upper P3 in lingual (F) and occlusal (G) views;Acinonyx jubatus(Schreber,1775),CD 3871, left upper P4 lacking protocone in occlusal (H) and lingual (I) views;J, K, Felis sp.: CD 675,right mandible with lower P3 and partial P4 in buccal (J) and lingual (K) views. Scale bars: 1 cm.