NEW DATA ON LINDHOLMEMYDID TURTLE LINDHOLMEMYS FROM THE LATE CRETACEOUS OF MONGOLIA

Abstract

Reinvestigation of a fragmentary lindholmemydid turtle from a Mongolian locality Sheergeen Gashoon (late Turonian-Santonian) suggested reassignment to Lindholmemys martinsoni Čkhikvadze, 1975. This restricts the stratigraphic range of the genus Mongolemys, to which the specimen was originally assigned. Additionally, new morphological data on L. martinsoni have been gathered and are presented in this paper. The Lindholmemydidae are considered here as a paraphyletic group uniting primitive testudinoids (all of which are known from Cretaceous to Paleocene of Asia). Their shell morphology is characterized by well developed plastral buttresses, which contact costal bones (synapomorphy of testudinoids, see Gaffney & Meylan 1988) and by complete (uninterrupted) row of inframarginal scutes (primitive character).