Hypolagus beremendensis ( Petényi, 1864 )

Popov, Vasil V., 2004, Pliocene small mammals (Mammalia, Lipotyphla, Chiroptera, Lagomorpha, Rodentia) from Muselievo (North Bulgaria), Geodiversitas 26 (3), pp. 403-491 : 443

Hypolagus beremendensis ( Petényi, 1864) ( Fig. 22 G-I)

Lepus beremendensis Petényi, 1864: 77 .

Pliolagus beremendensis – Kormos 1934a: 65-78, figs 1-3.

Pliolagus tothi Kretzoi, 1941: 308-335 , figs 1-7.

Hypolagus brachignathus – Sych 1965: 2-88, pls I-VII, figs 1-30.

Hypolagus beremendensis – Janossy 1963: 125.

MATERIAL EXAMINED. — 5 p3 (Ms94-96, Ms394).

MEASUREMENTS. — p3 (L × W): 3.3 × 3.0; 3.25 × 3.07; 2.75 × 3.12; 3.15 × -.

DESCRIPTION

p3: the occlusal surface is nearly triangular. There are two reentrant folds on the buccal side. The anterior one (protoflexid) is shallow; the posterior one (hypoflexid) is deep, reaching the medial axis of the occlusal surface. In two specimens, the posterior wall of this reentrant fold is slightly undulated. In one tooth, there is an enamel islet near the end of hypoflexid.

REMARKS

The available p3s are clearly smaller than the late Miocene rabbit, Hypolagus igrmovi Gureev, 1964 ( Averianov 1996) . In size and morphology they are similar to the Pliocene and early Pleistocene forms of the genus that are often considered to belong to two different species: H. beremendensis and H. brachignathus , respectively. According to Fladerer & Reiner (1996), they should be considered as two chronosubspecies. According to Sych (1965), the difference between H. brachignathus and Pliolagus tothi concerning the size and the occurrence of a lingual reentrant fold on p 3 in the last form fall within the ontogenetic variability of the first species. Two out of the three p3s available belong to the primitive morphotypes as defined by Fladerer (1987) and Fladerer & Reiner (1996) (edged margin of the talonid; short, triangular trigonid; undulated distal wall of the hypoflexid) characteristic for the Pliocene form. One p3 is slightly more advanced in having an enlargement of the mesial margin of the trigonid and in the presence of an enamel islet. Thus, the form from Muselievo can be considered as a progressive stage of H. beremendensis beremendensis .

Genus Trischizolagus Radulesco & Samson, 1967

Figures

FIG. 22. — A-F, Pliopentalagus dietrichi (Fejfar, 1961), p3 in occlusal view; A, left, Ms86; B, right, Ms87; C, right, Ms88; D, left, Ms91; E, right, Ms89; F, right, Ms90; G-I, Hypolagus beremendensis (Petényi, 1864), p3 in occlusal view; G, left, Ms95; H, right, Ms94; I, right, Ms96. Scale bar: 1 mm.