Ochotona, Link, 1795

Čermák, Stanislav & Rekovets, Leonid I., 2010, Early Pliocene ochotonids (Mammalia, Lagomorpha) from Southern Ukraine, Geodiversitas 32 (1), pp. 107-120 : 116

Ochotona sp. 1 ( Fig. 2R )

MATERIAL EXAMINED. — One isolated left p3 ( FRA 11) of black colour.

LOCALITY. — Frunzovka-1 (Odessa province, Ukraine); Early Pliocene (Ruscinian, MN 14) ( Fig. 1).

MEASUREMENTS. — L = 1.73, ccd = 0.11, anteroconid (L = 1.11, W = 0.74), posteroconid (L = 1.00, W = 1.85).

DESCRIPTION

Among the studied ochotonids from Frunzovka-1, there is one p3 which is strongly different from all specimens under study. The related p3 belongs to a medium-large sized ochotonid.The tooth is unique in its long and markedly narrow anteroconid with cement free depressions on its anterior sides. Together with short and wide posteroconid, they form a distinctly triangular appearance of the occlusal outline. The proto- and paraflexid are oriented notably posteriorly; the latter is slightly longer and more curved.

COMPARISON

The specimen under study differs from all the above mentioned taxa in its distinctly narrower p3 anteroconid, and in its para- and protoflexid development. The specimen is smaller than Bellatonoides kalfense , Pliolagomys species, and Ochotona eximia ; at the same time, it is larger than Pseudobellatona relicta , Ochotonoma species, Ochotona antiqua , O. pseudopusilla , O. ursui , and Villányian-Biharian species of Ochotona known from Central Europe (see above for the measurements).

It might well be that this individual represents a new species of Ochotona . However, the intraspecific variability of p 3 in O. antiqua is high. Therefore, based on one distinct p3only, the above mentioned differences may represent an unusual morphologic variation of O. antiqua ’s p3. In any case, the lack of additional p3s does not allow us to a new species assignment here, thus we assign this p3 tentatively to Ochotona sp. 1.

Figures

FIG. 2. — Morphology of p3 in studied ochotonids from the Early Pliocene (Early Ruscinian, MN 14) of southern Ukraine (Odesskaya Province):A-L, Ochotona antiqua Argyropulo & Pidoplichko,1939 from Novopetrovka (I, lectotype);M-Q, O. antiqua from Frunzovka-1; R, Ochotona sp. 1 from Frunzovka-1; S, Pseudobellatona relicta Topachevsky,Nesin & Topachevsky,1993 from Krasnopol (holotype). All teeth are figured as left specimens (A, C, K-M and P are reversed). Scale bar: 1 mm.