Two new species of Gobiconodon (Mammalia, Eutriconodonta, Gobiconodontidae) from the Lower Cretaceous Shahai and Fuxin formations, northeastern China

Abstract

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 2.1.2.5, 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 2.1.3.5, 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.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:608F5A43-AE4D-41CF-A2E4-1C9C6CFCA67C

Keywords::

• China
• Early Cretaceous
• Gobiconodon haizhouensis
• Gobiconodon tomidai
• Gobiconodontidae
• Mammalia

Acknowledgements

The authors thank Shu-Hua Xie for specimen preparation, and Zheng-Lu Chang, Takeshi Setoguchi and others for their assistance, advice, and support with this study. Scanning electron micrographs were taken by Wen-Ding Zhang. This paper was greatly improved by numerous significant suggestions of Leandro C. Gaetano and another anonymous reviewer.

Additional information

Funding

This study was partly supported by a Grant-in-Aid for Young Scientists (B) [grant number 24740349] from the Japan Society for the Promotion of Science awarded to N. Kusuhashi, and Projet International de Coopération Scientifique (DINASIA) from Centre National de la Recherche Scientifique, France, to N. Kusuhashi.