Rook et al.—Pliocene Canidae from Sighnaghi, Georgia
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closely resembles that of V. alopecoides from Pirro Nord and Dafnero-1 in general shape, with the distally inclined proto- conid, the reduced metaconid, and slightly larger hypoconid compared to the entoconid and the presence of an accessory cuspulid mesial to the entoconid. The talonid of V. alopecoides is slightly shorter mesiodistally when compared to the Kvabebi specimen. The scatter plot of the m1 length and width of Vulpes
Figure 4. Vulpes cf. V. alopecoides from Kvabebi. MG-29-2013/461 (K260), right hemimandible fragment, in buccal (1), lingual (2), and occlusal (3) views. Scale bar = 1 cm.
Description.—The fragment MG-29-2013/461 (K260) is very small in dimensions compared to the other specimens from Kvabebi. The ventral margin of the corpus of the mandible is preserved in a small, curved portion below the m2 (e.g., Fig. 4). The m1 possesses a proportionately high paraconid, a higher and distally curved protoconid and a prominent, slightly indi- vidualized metaconid. The latter is in line with the distal margin of the protoconid, so it is not visible in buccal view. The talonid basin is deep, with a large hypoconid and a smaller entoconid. These cuspulids are of the same height and are connected by a cristid. On the buccal side, there is a cingulid. The m2 is bean- shaped, with a larger mesial part compared the distal. The pro- toconid has a larger base than the metaconid, but both cuspulids have the same height. Mesial to the protoconid is a prominent cristid that ends in a faint accessory cuspulid. On the mesio- buccal side, a cingulid is well developed. Distal to the proto- conid is a large hypoconid, and the lingual side is bounded by a cristid with a low entoconid. MG 29-2013/461 (K260) mea- surements are as follows: m1 L = 131mm; m1 W = 5.5mm; trm1 L = 8.5mm; m2 L = 6.2mm; m2 W = 4.4mm; M m1 B = 4.5mm; M m1 H = 11.1mm.
Remarks.—The extant species V. vulpes is larger in size com- pared to the smallest canid from Kvabebi. Moreover, it pos- sesses several features (such as an individualized and large metaconid, a high and pointy accessory cuspulid between entoconid and metaconid, and an oval-shaped m2 with numer- ous distal accessory cuspulids) that cannot be found in MG 29-2013/461 (K260). Unlike the arctic fox V. lagopus, the smallest Kvabebi canid possesses the m1 entoconid and hypo- conid close to one another, a reduced talonid basin, and a slender m2. Compared to V. praecorsac from the Odessa catacombs and Püspökfürdö (Kormos, 1932; Odintzov, 1965), MG 29-2013/ 461 (K260) shows some differences (e.g., a slender m1 proto- conid, in lateral view; the lower carnassial less compressed buccolingually; and the m2 more elongated mesiodistally and bean-shaped in occlusal view, with a reduced talonid portion compared to the large trigonid). Following the discussion in Madurell-Malapeira et al. (2009), some of the distinctive features of V. praeglacialis are: (1) a large and individualized m1 metaconid; (2) a wide bicuspid talonid with a larger hypo- conid; and (3) a large and wide m2, with the protoconid larger than the metaconid. All these features contrast with those of MG 29-2013/461 (K260). In fact, the morphology of the m1 of
is shown in Figure 5. Together with the two extant species, V. vulpes and V. lagopus, we also include the Eurasian Plio-Pleistocene species V. praecorsac, V. praeglacialis, and V. alopecoides for comparison. All the fossil species fall within the variability of extant
V. lagopus and are generally smaller than V. vulpes. Vulpes praecorsac is characterized by extremely reduced dimensions compared to the other two fossil species, being at the lower dimensional range of the extant V. lagopus. Vulpes praeglacialis and V. alopecoides are comparable in size. An additional scatter plot ofm1 L and the ratio ofm1 W/L allows an appreciation of the differences in robustness of the lower carnassial of Vulpes fossil species, showing that the Kvabebi specimen, like V. alopecoides, is characterized by stouter proportions of the m1 (Fig. 6). MG 29-2013/461 (K260) falls within the upper dimen-
sional range of the early Pleistocene V. alopecoides sample and shares with the same species a comparable degree of robustness. Based on its morphological features, size, and proportions, we are prone to identify this specimen as Vulpes cf. V. alopecoides.
Tribe Canini Fischer von Waldheim, 1817 Genus Eucyon Tedford and Qiu, 1996
Eucyon sp.
1972 Nyctereutes megamastoides Vekua, p. 41. 2009 Nyctereutes megamastoides Agustí et al., p. 3277. 2009 Eucyon sp. Agustí et al., p. 3277.
Materials.—MG 29-1 (K222) neurocranium; MG 29-2013/607 right p4; MG 29-2013/608 left p4; MG 29-2013/603 right m1.
Description.—MG 29-1 (K222) is a neurocranium preserving partial dorsal portions of the orbits and the frontals. The neuro- cranium (Fig. 7) is globular in shape, with inflated frontal sinuses that expand into the postorbital constriction. Their extension into the frontal is also testified by the dorsal outline of the frontals that bulge in lateral view, at level of the postorbital processes. The inflation of the frontal sinuses is also revealed by the smoothness of the parasagittal crest on top of them. In caudal view, the supraoccipital shield is fan-shaped, with an expansion at level of the mastoid process. The inions fail to overhang the condyles. The two premolars show high protoconids, slightly arched
lingually; on their distal sides. There is a distal individualized and large cuspulid, which is not in linewith the protoconid, but sits sits slightly buccally. Distally, there is a cuspulid-like cingulid. In the occlusal view, the m1 is elongatedmesio-distally and slender. The paraconid is low, whereas the protoconid is high and slightly inclined backwards. Themetaconid is reduced in height and rather individualized from the protoconid; it is positioned slightly
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