Tugenictis sp, Morales & Pickford, 2005

Werdelin, Lars, 2019, Middle Miocene Carnivora and Hyaenodonta from Fort Ternan, western Kenya, Geodiversitas 41 (6), pp. 267-283 : 277

cf. Tugenictis sp .

MATERIAL EXAMINED. — KNM-FT 3360, right m1; KNM-FT 3361, left M1; KNM-FT 3363, right M2; KNM-FT 3368, left m1; KNM-FT 3398, left M1.

DESCRIPTION

KNM-FT 3360, KNM-FT 3368 ( Fig. 4 D-F).

These lower carnassials are short, broad teeth. The trigonid makes up about 60% of the total length of the tooth. The three trigonid cusps are nearly equally tall. The protoconid is set far buccally. The paraconid is set anteriorly with the angle metaconid-paraconid-carnassial notch close to 75°, showing the central valley to be broader than in the m1s described above, and almost flat centrally. The protoconid is set near the buccal border. The angle between pre- and postprotocristids is about 125°. The metaconid is set on the lingual margin directly distal to the paraconid. There is a notable cristid extending from the mesiobuccal margin of the metaconid and halfway across the tooth, where a notch separates it from the postprotocristid. The cristid obliqua is prominent and ends distally at a large and tall hypoconid. The entoconid is nearly as tall as the hypoconid but more crescentic in shape. There is no distinct hypoconulid.

Measurements. KNM-FT 3360: Lm1 9.6; Wm1 5.8; Ltm1 6.0. KNM-FT 3368: Lm1 9.9; Wm1 5.9; Ltm1 6.2.

KNM-FT 3361, KNM-FT 3398 ( Fig. 4G, H )

These upper first molars are distinctive and very similar morphologically, though they differ in details. They are superficially similar to amphicyonid upper molars, but their lingual shelf and buccal cingulum are broader and their trigon structure different. They are also smalIer than known African amphicyonid upper molars (M1 or M2 – M3 is morphologically very different and reduced) and no known amphicyonid has an upper molar in which the buccal shelf is the broadest part of the tooth. The teeth are mesiodistally very symmetric and it is difficult to determine which end is mesial and which is distal. The identification mesial-distal made here is tentative, with the larger and more rounded part of the buccal margin considered the paracone and therefore mesial. In this interpretation the paracone is longer and more crescent-shaped than the metacone. The stylar shelf is about equally wide buccal to both cusps. Neither specimen shows any sign of stylar cusps, but in KNM-FT 3361 the paracone shelf has a distinct marginal crest. The metacone is slightly smaller and rounder than the paracone. In both teeth there are strong pre- and postprotocristae that run from mesial to the paracone and distal to the metacone lingually towards the protocone, which is large and crescent-shaped. In KNM-FT 3398 these cristae show considerable wear. Both teeth have a small protoconule mesial to the protocone. The lingual cingulum is developed enough to be considered a shelf, especially in KNM-FT 3361. In both teeth the highest point of the cingulum is slightly mesial to the midline.

Measurements. KNM-FT 3361: LM1 6.5; WM1 10.7. KNM-FT 3398: LM1 7.0; WM1 10.2.

KNM-FT 3363 ( Fig. 4I )

This M2 is closely similar in many respects to the preceding two molars, but is smaller, with curved mesial and distal margins and a reduced metastyle wing and metacone. Apart from this, the stylar shelf, paracone, metacone, and buccal shelf are very similar to the M1s. All these features combined make it clear that this is the M2 of the same species. In fact, it is possible that KNM-FT 3361 and KNM-FT 3363 belong to the same individual because they are cataloged under the same field number, but this cannot be demonstrated definitively.

Measurements. LM2 5.2; WM2 8.7.

DISCUSSION

The association between the upper and lower teeth here is tentative and motivated by the similarity of the m1s to those of Kanuites as described above, and Orangictis gariepensis as described by Morales et al. (2001b) and Morales & Pickford (2011). The approximately coeval Tugenictis ngororaensis Morales & Pickford (2005) is only known from lower dentition material, but also shares similarities with the Fort Ternan specimens where comparisons are possible. Given that all these species have been identified as paradoxurines, the Fort Ternan m1s are also likely to belong to a paradoxurine. The upper teeth assigned here can be identified as paradoxurine by their broad stylar and buccal shelves and, in the case of M1, by the occlusal surface symmetry. In size they fit with the m1s listed here and therefore all these teeth are tentatively assigned to the same taxon, which likely has affinities to the paradoxurine taxa mentioned above.

Figures

FIG. 4. — Viverridae from Fort Ternan: A-C, Kanuites lewisae KNM-FT 3876, right m1 in buccal (A), lingual (B), and occlusal (C) views; D, E, cf. Tugenictis sp., KNM-FT 15093, right m1 in buccal (D), lingual (E), and occlusal (F) views; G, cf. Tugenictis sp., KNM-FT 3361, left M1 in occlusal view; H, cf. Tugenictis sp., KNM-FT 3398, left M1 in occlusal view; I, cf. Tugenictis sp., KNM-FT 3363, right M2 in occlusal view; J-L, Viverrinae gen. et sp. indet., KNM-FT 3373, right m1 in buccal (J), lingual (K), and occlusal (L) views; M-O, Kanuites cf. lewisae, KNM-FT 8744A, right hemimandible with dc, p1, dp2-dp4 in buccal (M), lingual (N), and occlusal (O) views; P, Kanuites lewisae (holotype),KNM-FT 8747,cranium with right C-P4, left P2-P4 in ventral view; Q, Kanuites cf. lewisae, KNM-FT 8750, cranium with right P1 and DP2-DP4, left P1 and DP3-DP4. Scale bars: A-L, 10 mm; M-Q, 50 mm.