Nógrád Megyei Múzeumok Évkönyve XXV. (2001)

Természettudomány - Dr. Hír János: Új középső miocén rágcsálófaunák Észak-Magyarországról

Abstract New Middle Miocène rodent faunas from Northern Hungary The author gives the results of a field campaign collecting microvertebrate fossils from the nonmarine Middle Miocène of Northern Hungary. The campaign is organised with the help of the Hungárián National Science Fund (OTKA T029148). During the course of it a great deal of sample was washed and sieved. The collected finds were given for specialists: József Kókay: molluscs, Árpád Dávid and Mariann Bosnakoff: Pisces (otoliths), Márton Venczel: Amphibia, Reptilia, Erika Gál and Eugen Kessler: Aves, Lukács Mészáros: Insectivora. The élaboration of the rodents is managed by the author. All the sampled localities come under the Sajó Valley Formation (Fig. 1. ). This lithostratigraphical unit consists of a terrestrial -lacustrine séries (HÁMOR, 1985). It was described as "Sarmatian terrestrial séquence" by the earlier geological literature. Middle Miocène volcanites and marine sédiments are in the floor of the formation. The Sarmatian Kozárd Formation (containing "normal" Sarmatian brackish mollusc fauna) is intertounged with the Sajó Valley Formation. The overlyers are différent Lower Pannonian sédiments. The earlier scholars stressed the lacking of fossils in the "terrestric Sarmatian" with the exception of sporadic nonmarine molluscs, silicified trunks, bones and leaf imprints. We tried to verify the présence of microvertebrate faunas in the formation. /. Sámsonháza The small village is situated in the Southeastern part of Nógrád County, ten kilomètres from the town Pásztó. In the surroundings of the Settlements outcrops of limestone and différent calcareous sédiments are well known with Early Badenian marine fauna. This séries was classified as Sámsonháza Formation by HÁMOR (1985). On the top of this complex fluviatile -continental sédiments were described with freshwater molluscs and sporadic vertebrate fossils (SÜMEGHY 1925, NOSZKY 1940). In 1995 a diatomaceous mud layer was found with bones by Hir in the deep erosional trench "Oszkoruzsa -árok". 4 tones of this kind of sédiment was washwed producing the next rodent matériái : Spermophilinus bredai Muscardinus sansaniensis Microdyromys koenigswaldi Miodyromys aegercü Miodyromys sp. Megacricetodon minor Democricetodon sp. Crícetodon cf. hungaricus Eumyarion médius After the opinion of KÓKAY (in HIR et al 1998) the rieh mollusc fauna of the boné -bearing layer refers to the Middle Badenian. 240