Abstract: A mammalian lower jaw with the last two premolars and four molars was discovered from the late Early Cretaceous ( Aptian-Albian) Shahai Formation in Heishan County , Liaoning Province , China. It represents the first record of " eupantotherian" in China. It is characterized by submolarized last premolar , relatively large but unbasined talonid and lacking facet 5 on molars , enlarged m4 and elevated angular process. A new genus and species, Mozomus shihamai gen. et sp. nov. , is named based on the specimen. Morphologically , the new taxon is similar to the Mongolian KielanLherium of ? Aptian or ? Albian in general ( Dashzeveg and Kielan-Jaworowska, 1984) , but differs from the latter, probably primitively, in lacking facet 5 on molars. Kielantheriids were regarded as plesiomorphic in molar structure among mammals with tribosphenic pattern " and possess " a putative phylogenetic position as a stem boreosphenidan" (Luo et al. , 2002 : 11 ) . Reexamination of the specimen of Kielantherium gobiensis ( GI PST 10-16) brings into question of the shearing facet, and a comparison between Kielantherium and Mozomus is given in the present paper.

摘要： 记述了在中国首次发现的采自辽宁黑山县八道壕矿区早白垩世晚期沙海组的一件“eupantotherian”(“真古兽类”)下颌骨化石。标本保存了最后两个前臼齿和4个臼齿，它以抬高的下颌角突，半臼齿化的最后一枚前臼齿，臼齿上面积增大但未发育成完整盆形的跟座，尚未形成的facet-5，及加长的最后臼齿等特点有别于所有已知的“eupantotherian”和具有雏形磨楔式臼齿的Kielantherium，被命名为一新属新种，Mozomus shikamai gen．et sp．nov．(鹿间明镇古兽)，并由它而创建