Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 90. (Budapest 1998)

Hír, J.: Cricetids (Rodentia, Mammalia) of the Early Pleistocene vertebrate fauna of Somssich-hegy 2 (Southern Hungary, Villány Mountains)

CONCLUSIONS After the biometrical and morphological analysis of the Cricetus finds from Somssich-hegy 2 and from the above mentioned other localities we can draw the following conclusions. 1. The largest hamster finds of Somssich-hegy 2 are the oldest representatives of the real "large sized" (larger than C. nanus) Cricetus in the Carpathian Basin. 2. The evolution of Cricetus in the Hungarian Pleistocene probably occurred in three independent lines. In this question the opinion of the present author differs from the statement of PRADEL (1985) who declared that all the big Pleistocene hamsters make up a common line leading to the recent C. cricetus. In the C. praeglacialis-C. cricetus line the measurements decreased and the morphology simplified (HÍR 1997a). The second one is the C. runtonensis line. We tried to verify the evolutionary relation between the hamster materials of Somssich-hegy 2. and Solymár on the basis of the measurements (Figs 20-25) and after the results of the morphotype-analysis, e.g. the dominancy of A01 type in M2 molars (Table 2), the subdominant position of Fia type in m 1 molars (Table 4), and the presence of the m2 and m3 morphotypes with mesolophid and "paramesolophid" in both materials. In the C. runtonensis line the measurements slightly increased and the morphology became complicated (HÍR 1997/;). The third evolutionary line is probably the C. major line which is poorly represented in the Hungarian fossil material and it was not studied in details by the author (with the exception of a small sample from the fauna of Subpiatra, Romania: HÍR & VENCZEL 1991). This species was found in two periods of the Hungarian Pleistocene: the Tarkő Phase and the Eemian (Varbó Phase). JÁNOSSY (1986) published the hamster from Tarkő as "C. runtonensis", but this determination is erroneous as demonstrated by the extra large dental measurements of the material. 3. In the sequence of Somssich-hegy 2 the C. runtonensis has maximal abundancy between the 39-43 layers (Fig. 33). In this level the most frequent arvicolids are Lagurus species (JÁNOSSY 1990, Fig. 2). Based on its dominancy we can presume the preference of this hamster for arid, continental climate, although it is not characteristic of all Pleistocene hamsters, e.g. C. runtonensis ssp. from Solymár and C. major in Tarkő and Subpiatra lived in a forested biotope (HÍR 1996c, HÍR & VENCZEL 1991). The material of Somssich-hegy 2 represents the Nagyharsányhegy Phase of the Hungarian Early Pleistocene (JÁNOSSY 1986). KORDOS (1993) determined it as the typefauna of the Mimomys savini - Mimomys pusillus zone. We found four hamster species in the fauna which represents the highest diversity of the cricetids during the Pleistocene in the Carpathian Basin. These four species were found together in Hungary only in the fauna of the Hajnóczy Cave in Northern Hungary (Bükk Mountains) (HÍR 1992), where Mimomys savini and Mimomys pusillus were found as well. Acknowledgements - The author would like to express his sincere thanks to Prof. DÉNES JÁNOSSY for his permission to study the fauna of Somssich-hegy 2. The study was supported by the Hungarian Scientific Research Fund (OTKA grant No. T-014412).