Propliomys cf. hungaricus Kormos, 1934

Popov, Vasil V., 2004, Pliocene small mammals (Mammalia, Lipotyphla, Chiroptera, Lagomorpha, Rodentia) from Muselievo (North Bulgaria), Geodiversitas 26 (3), pp. 403-491 : 461

Propliomys cf. hungaricus Kormos, 1934 ( Figs 31 B-F; 32)

MATERIAL EXAMINED. — 2 m 1 (Ms43-44) and 4 fragmentary m1 (Ms45-48), 3 M3 (Ms49-56).

MEASUREMENTS. — Lm1 = 2.75; 3.05; Wm1 = 1.05; 1.15; LM3 = 1.45; 1.75; 1.70.

DESCRIPTION

The molars lack crown-cementum. Most m1s have enamel lightly differentiated, somewhat thicker on the anterior sides of the triangles. The anterolingual enamel-free area (anterosinuid) is relatively high. Two m1 fragments bear a Mimomys -ridge and a prismfold but these elements are not very prominent on the occlusal surface; the prismfold is wide and shallow while the relatively weak Mimomys -ridge is shifted anteriorly. On the lateral side of the crown, these elements are poorly pronounced on the uppermost part of the wall only, and probably vanish quickly with tooth wear.

M3: the second reentrant angle (BRA2) is rather shallow. In contrast, the second lingual reentrant angle (LRA2) and BRA2 are deep and separate the occlusal surface in three dentine fields; the second buccal salient angle (BSA2) is incipient; the posterior loop (PC1) is short and simple; two roots; the dentine trucks are not developed (but see specimen Ms50, which shows enamel interruptions); there are no enamel islets.

REMARKS

The m1 material from Muselievo is similar to Propliomys hungaricus (Kormos, 1934) a species, which is common in many European Pliocene faunas ( Kormos 1934b: fig. 46; De Bruijn & Van der Meulen 1975: pl. 1, figs 5, 6; Fejfar & Storch 1990). However, it differs from this species ( De Bruijn & Van der Meulen 1975: pl. 2, fig. 10) by the structure of M3. The M 3 in Propliomys hungaricus shows three roots, a posterior enamel islet (but see also Rabeder 1981: abb. 164, 6) and a large confluence between the T3 and the elongated posterior loop ( Kowalski 1960: 471; De Bruijn & Van der Meulen 1975; Topachevsky & Nesin 1989). The small M3 sample from Muselievo is similar with Pliomys graecus De Bruijn & Van der Meulen, 1975 (Tourkobounia 1, Greece, lower Villanyian) in having two-rooted M3s and a reduced posterior loop. On the other hand, the hypsodonty as well as the height of the enamel free areas of some of the m1s (Ms43, 47) distinguish the form from Muselievo from P. graecus . In these respects, the available m1s are similar with P. hungaricus from Csarnóta-1. The scarce remains from Muselievo do not permit detailed comparisons, so the determination remains tentative until a more complete material will be known.

Figures

FIG. 31. — A, Dolomys cf. nehringi Kretzoi, 1959, left M3, Ms41, occlusal view; B-F, Propliomys cf. hungaricus Kormos, 1934; B, left M3, Ms49, occlusal view; C, left M3, Ms56, occlusal view; D, left M3, Ms51, occlusal view; E, left M3, Ms51, buccal view; F, left M3, Ms51, lingual view. Scale bar: 1 mm.