EARLY MIOCENE SMALL MAMMALS FROM THE NORTH ARAL REGION (KAZAKHSTAN) WITH SPECIAL REFERENCE TO THEIR BIOSTRATIGRAPHIC SIGNIFICANCE

Abstract

The Aral Faunal Assemblage is rich in small mammals. Insectivores there include the hedgehogs Galerix sp., Exallerix efialtes Lopatin, Amphechinus akespensis Lopatin, A. microdus Lopatin, and Amphechinus sp.; the moles Desmanella compacta sp. nov., Pseudoparatalpa lavrovi (Bendukidze), Myxomygale asiaprima sp. nov., and Hugueneya sp.; and the soricids Gobisorex akhmetievi sp. nov., Atasorex edax gen. et sp. nov., and Aralosorex kalini Lopatin. Lagomorphs are represented by Desmatolagus simplex (Argyropulo), D. periaralicus Lopatin, D. veletus Lopatin (Desmatolagidae), and Sinolagomys pachygnathus Li et Qiu (Ochotonidae). Rodents are very diverse and include the aplodontids Prosciurus daxnerae Lopatin and Ansomys crucifer Lopatin; the beavers Steneofiber kumbulakensis (Lytschev), S. schokensis (Bendukidze), and Asiacastor sp.; the eomyids Eomyodon bolligeri Lopatin and Pseudotheridomys yanshini Lopatin; the zapodids Plesiosminthus tereskentensis Lopatin, Parasminthus debruijni Lopatin, and Bohlinosminthus cubitalus Lopatin; the cricetids Eucricetodon occasionalis Lopatin, Eumyarion tremulus Lopatin, Eumyarion sp., and Aralocricetodon schokensis Bendukidze; the primitive mole rat Argyromys aralensis (Argyropulo); the tachyoryctoidids Tachyoryctoides glikmani (Vorontzov), Tachyoryctoides sp., Aralomys gigas Argyropulo, and Eumysodon spurius Argyropulo; and the ctenodactylid Yindirtemys birgeri Bendukidze. Based on taxonomic composition, the assemblage is dated as the beginning of the Miocene (Early Aquitanian) and compared to the MN 1 European Mammal Zone. It is proposed to consider the Aral biochron as the reference level NMU 1, that is, the basal unit of the biochronological scale of the Neogene of inner Asia, which corresponds to the earliest phase of the Xiejian Asian Land Mammal Age (Earliest Xiejian or Aralian).