A NEW SPECIES OF TINOSAURUS FROM LUSHIH,HONAN

A new fossil lizard of late Eocene was discovered at Lushih,Honan in 1957.The material includes a right upper jaw,bearing 10 teeth,a median portion of right lower jaw,bearing 13 teeth and a broken jugal (?). According to the characters of teeth,it is obvious that the Honan specimen belongs to Tinosaurus,established by Marsh (1872). The maxilla is comparatively complete,with 12 mm in length.The preserved teeth are closely spaced.They are acrodont,short,compressed transversely,with pointed apices.The posterior ones are tricuspid.The lateral cusps are lost in the anterior ones. The last three teeth are overlapped each other (Plate I,fig.1).The maxillary teeth re- duce in size from back to front,with a tendency to disappear on the most anterior por- tion. Only part of the dentary is preserved,with 13 teeth,13.5 mm in length.The charac- ters of teeth are similar to those of the upper jaw.The four on the most posterior por- tion are subacrodont,overlapped one by one.The groove for Meckel's cartilage is large. The Honan specimen is thus distinguished from T.stenodon and T.pristinus by it close spacing of teeth and better defined grooves that set off the denticles from the large median cusp.It also differs from T.asiaticus by the subacrodont teeth and the lapping of posterior teeth.Therefore,a new species—Tinosaurus lushihensis is pro- posed. The geological age of T.lushihensis is early late Eocene.