Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 86. (Budapest 1994)

Hír, J.: Cricetus cricetus nanus Schaub, 1930 (Mammalia, Rodentia) finds from the Carpathian Basin

m2. The morphology of the tooth is very variable. We can distinguish 17 morphotypes (Fig. 9, Table 10). The antero-lingual cingulum is common, developed in the A, C, E, H, I, J, L, M, N, P types. A short mesolophid is visible in the C, D, G, L, N types. Ectostylid exists in the B, H, I, L, O types. The posterolophid forms an enamel ring in the B, D, E, F, J, L, M, N, O, Q types. This feature is rare in the molars of Pleistocene Allocricetus species (HÍR 1989, 1992, 1993). The "posterolophulid" is found in the F, I, M, N, P morphotypes. m3. The variability of this tooth is also remarkable. It has 8 morphotypes (Fig. 10, Table 12). Antero-lingual cingulum is developed in the B, C, D, F, G, H types, but does not exist in the A, E types. The mesolophid is common and its build-up is diverse. In the A, B types the mesolophid is short The most frequent G-type has a longer mesolophid In the H-type the mesolophid is transversally directed. In the C, D types this region is complicated because the protoconid has two posterior arms connected with the hypolophulide and with the anterior part of the endoconid. In these cases a closed central basin is visible on the tooth crowns. The short mesolophid is connected with the postero-lingual arm of the protoconid. In the E, F morpholypes (Fig. 10) the mesolophid does not exist. In the B morphotype the lingual margin of the protoconid has short accessory elements. In the A, D-types the lingual cingulum is strong. H, C, B morphotypes are not found in the Hungarian Allocricetus materials investigated by the author. In the proportion of the tooth in the complete tooth-rows there is no real difference between the investigated Cricetus cricetus nanus, Allocricetus and Cricetulus materials (Tables 14-15). Cricetus cricetus nanus is well distinguishable from Allocricetus éhiki and from the large sized Pleistocene cricetids {Cricetus cricetus praeglacialis SCHAUB, 1930, Cricetus runtonensis NEWTON. 1909) on the basis of the measurements (Figs 11, 12, 13, 14, 15, 16, 17, 18) Its metrical similarity to the recent Mesocricetus auratus WATERIIOUSE, 1839 is remarkable, but its morphology is strongly different. The dentition of a Mesocricetus material from Turkey was studied in detail by HÍR (1992b). After this investigation the most important differences are briefly as follow: The Mesocricetus molars are generally higher crowned and better segmented. The tooth crown is laterally narrower between the main cone-pairs. The posterolophules and posterolophulids are better developed in every case. In the M

1 molars parastyle and protostyle conelets occur. Mesolophe does not exist in the Ml, M2 molars. In the M3 molars the C, D elements are absent. In the ml-m2-m3 molars the mesolophids are more frequent. In the crowns of the m3 molars the B, C, D, H configurations are not found. Cricetus cricetus nanus materials were found in the next Lower Pleistocene faunas (after MAUL 1990 with the original codes) (Fig. 19). Figs 7-8. Anterior part of ml molars: 7 = without developed anterolophule, 8 = with developed anterolophule. - Fig. 9. Investigated elements of the occlusal surface in the m2 molars. ALC = antero-lingual cingulum, ML = mesolophid, ECSD = ectostylide, PLLD = "posterolophulid", PLD = posterolophid DISCUSSION