Occurrences of Sinolagomys (Lagomorpha) from the Valley of Lakes (Mongolia)

Margarita Erbajeva,Bayarmaa Baatarjav,Lawrence J Flynn,Gudrun Daxner-Höck

doi:10.1007/s12549-016-0262-z

Abstract

The genus Sinolagomys is an early representative of the family Ochotonidae, appearing first in the late early Oligocene of Central Asia. It is known in China from Shargaltein Tal, Taben Buluk, Ulan Tatal, and northern Junggaria, and a few specimens from Tatal Gol, Mongolia have been published. For most occurrences, the genus is not represented by many specimens. Extensive studies in the Valley of Lakes, Central Mongolia, have produced a large number of sinolagomyin fossils spanning at least 10 million years and belonging to five species: Sinolagomys kansuensis, Sinolagomys major, Sinolagomys gracilis, Sinolagomys ulungurensis, and Sinolagomys badamae sp. nov. Descriptions of these are given, as well as definition of the new species. Sinolagomyins flourished during the late Oligocene and early Miocene and came to occupy vast territories from China through Mongolia and Kazakhstan. The evolution of this ochotonid group is characterized by increasing taxonomic diversity and progressive development of rootless cheek teeth.

Highlights

This article is a contribution to the special issue BThe Valley of Lakes in Mongolia, a key area of Cenozoic mammal evolution and stratigraphy^This article is registered in Zoobank under: urn:lsid:zoobank.org: act:F0708E7BEBF7-4571-A756-965ADE5C87CDDivinity Avenue, Cambridge, MA 02138, USAThe Order Lagomorpha, originating in Central Asia likely during the Paleocene Epoch (Asher et al 2005), was represented by a number of early stem group lagomorphs such as genera Khaychina, Eomylus, Amar, Zagmys, Mimotona, Eurymylus, Gomphos, placed variously in the higher taxa Anagalida and Mimotonidae
The present paper describes for the first time abundant fossil sinolagomyins collected from more than 50 localities of the Valley of Lakes, spanning in age the early late Oligocene to early Miocene
Fossils of Sinolagomys are rather well-preserved across the Oligocene to Miocene informal biozones C1–D of the Valley of Lakes in Central Mongolia

Summary

Introduction

This article is a contribution to the special issue BThe Valley of Lakes in Mongolia, a key area of Cenozoic mammal evolution and stratigraphy^. Later, based on material collected by the joint Soviet– Mongolian Paleontological expeditions, Gureev (1960) described from the Tatal Gol locality ten different lagomorph taxa, mostly desmatolagins, among which three fragments of ochotonid lower jaw with variable structure of p3 were discovered. Field work resulted in the collection of a great number of mammal fossils including lagomorphs in the region (Daxner-Höck et al 2017, this issue), in particular an impressive number of ochotonid specimens of the genus Sinolagomys stored in the NHMW (Vienna, Austria) and in the MPC/L (Ulaabaatar, Mongolia). Sinolagomyinae are a characteristic element of small mammalian assemblages of Central Mongolia (Valley of Lakes) They are a species-rich group playing an important role for palaeoenvironmental reconstruction in the region and they facilitate interregional correlations. The genus includes S. kansuensis Bohlin 1937 (type species), S. major Bohlin 1937, S. gracilis (Bohlin 1942), S. tatalgolicus Gureev 1960, S. ulungurensis Tong 1989, S. pachygnathus Li and Qiu 1980, and Sinolagomys badamae sp. nov

Material and methods

16 M2 W hyp

12 M2 W hyp 2

Conclusion