Two new species of Gobiconodon (Mammalia, Eutriconodonta, Gobiconodontidae) from the Lower Cretaceous Shahai and Fuxin formations, northeastern China
Kusuhashi et al
Two new gobiconodontid mammals, Gobiconodon tomidaisp. nov. and Gobiconodon haizhouensissp. nov., from the Lower Cretaceous (Aptian to Albian) Shahai and Fuxin Formations, respectively, in Liaoning Province, northeastern China, are described. Gobiconodon tomidaisp. nov. is a small-sized species of the genus characterised by the lower dental formula 220.127.116.11, a double-rooted p2, the molariform crown being mesiodistally longer than tall, and a distinct and almost continuous lingual cingulid on m2–m4. Gobiconodon haizhouensissp. nov. is of similar size to Gobiconodon tomidaisp. nov. and is characterised by the lower dental formula 18.104.22.168, the molariform crown being slightly taller than the mesiodistal length, and a well-developed and almost continuous lingual cingulid on m1–m3. The new materials indicate that the upper molariform count of most species of Gobiconodon is likely to be four, one less than the lower molariform count. Gobiconodon is the second mammalian genus common to the Jehol and Fuxin mammalian faunas.