Folia archeologica 51.
István Vörös: A magyarországi fosszilis Elephantidák biokronológiája
BIOCHRONOLOGY OF F OSSIL . ELEPHANTIDAE IN HUNGARY 13 enamel wall on the tooth lamella. Starting from the Lower Pleistocene till the Upper Pleistocene, the enamel thickness of the tooth lamella decreases from 4.2 mm to 1.0 mm (Table 1). In case of the Elephantidae, the process of decreasing of the enamel thickness took place not only on macro-, or species evolution level but also within the species (individuals) depending on anatomical positions, during ontogenesis. It happened in a way that in course of the lifetime of the animal, the mM2-3 and Ml members of the dentition show gradually more evolved "level of development" due to constant wear by chewing compared to the M2-3. The lamellae and the enamel wall of the niM2-3 and Ml are more thin, the index of tooth lamella is higher than the values measured on M2-3 on the same individual (KRETZOI et al. 1982.). "fhe microsystematical study of Elephantidae, parallel to other large mammals, makes possible a more exact palaeontological, biostratigraphical dating (KRETZOI et al. 1982) of the lithostratigraphical division of Hungarian loess, loess-like sediments and riverine gravel beds (PÉCSI 1965, 1975). The Carpathian Basin used to belong to the periglacial climatic zone and its fauna is partly different from the contemporary faunal assemblages outside the Carpathian Basin due to the mollifying effect of the Carpathians in respect of climatical extremities. On the other hand, its fauna, lying at the meeting point of several zoogeographical areas shows continuity towards the areas of Central and South-eastern Europe. There are so far 4 genera/subgenera of the family Elephantidae GRAY 1821 known from surface formations of the Upper Pliocene-Pleistocene in Hungary: species and subspecies of Archidiskodon Poi ILK. 1885, Parelephas OSBORN 1924, Mammuthus BURNETT 1830 and Palaeoloxodon M VISI MO IO 1924 (see further literature in VÖRÖS 1974, 1983). ARCHIDISKODON POHLIG 1885 All three species evolution level forms of the genus Archidiskodon are present in the Upper Pliocene and Lower Pleistocene in Hungary, corresponding to the southern areas of Eurasia. Archidiskodon gromovi (ALEKSEEVA et GARUTT 1965) Localities: Aszód (VÖRÖS 1985, Fig. 2. 1—2.); Szomód-Csúcsoshegy (from gravel at both sites); Visonta K-I. 1981, from the depth of 34 m, from grey-lilac mottled tuffaceous sediment (KRETZOI et al. 1982). Geological age: Arch, gromovi is known from the southern parts of the EastEuropean region from the beginning of the Late Pliocene from the lower horizon of the Akcagilian complex; from the Moldavski-Chapry fauna complex (Early Villafranchian) as well as I he Southern West-Siberian Podpusker-Lebajze fauna complex (GARUTT et BAJGUSEVA 1981). Hungarian finds of Arch, gromovi have no immediate faunistical, stratigraphical relation. At Aszód, the terminus post quam of the lower gravel bed containing the Arch, gromovi is the Lower Levantean sandy clay with Mastodon arvensis ( VÖRÖS 1985). Finds of Arch, gromovi, together with M. arvensis CROIZET et JOBERT and/or Zygolophodon (Mastodon ) borsoni HAYS ( = pavlovi OSBORN) from gravel terraces settled on Mastodon-bearing layers (Aszód, Szomód-Csúcsoshegy) or from luff-containing sandy clay (Visonta K-I 1981) sign an Upper Pliocene faunal stage, from
