CAJ | 학술논문

根据头骨和下颌建立了海龙一新属新种--短吻贫齿龙(Miodentosaurus brevis gen.et sp.nov.).其正型标本是采自贵州三叠纪法郎组的一具骨架(台中自然科学博物馆标本编号NMNS-004727/F003960).虽然头后骨胳还没有修理,但是几近完好的头骨和下颌显示出许多与众不同的特征,足以确定该标本代表了一新的海龙属种.短吻贫齿龙是个体较大的海龙,其全长超过4 m,头骨背部最长约为33 cm.吻直且极短是其最显著的特征之一.其他主要特征有:前颌骨沿前背中央有一隆嵴;上颌仅前颌骨有6枚圆锥形齿,无上颌骨齿;上颌骨沿前腹侧缘有一沟槽;下颌齿骨齿都集中在前端且至多不超过6枚.依据上述这些特征很易把短吻贫齿龙与其他已知海龙相区别.短吻贫齿龙头骨顶面松果孔大且很前位,头骨腭面的锄骨和翼骨均无齿,它的颈较长(至少可以辨认出13个颈椎).这些特征显示短吻贫齿龙可能与包括中国安顺龙属(Anshunsaurus)在内的Askeptosauroidea超科有相近的系统关系.
근거두골화하합건립료해룡일신속신충--단문빈치룡(Miodentosaurus brevis gen.et sp.nov.).기정형표본시채자귀주삼첩기법랑조적일구골가(태중자연과학박물관표본편호NMNS-004727/F003960).수연두후골각환몰유수리,단시궤근완호적두골화하합현시출허다여음불동적특정,족이학정해표본대표료일신적해룡속충.단문빈치룡시개체교대적해룡,기전장초과4 m,두골배부최장약위33 cm.문직차겁단시기최현저적특정지일.기타주요특정유:전합골연전배중앙유일륭척;상합부전합골유6매원추형치,무상합골치;상합골연전복측연유일구조;하합치골치도집중재전단차지다불초과6매.의거상술저사특정흔역파단문빈치룡여기타이지해룡상구별.단문빈치룡두골정면송과공대차흔전위,두골악면적서골화익골균무치,타적경교장(지소가이변인출13개경추).저사특정현시단문빈치룡가능여포괄중국안순룡속(Anshunsaurus)재내적Askeptosauroidea초과유상근적계통관계.
A new thalattosaurian.Miodentosaurus brevis gen.et sp.nov.,is established on the basis of the fairly preserved skull and mandible of a skeleton from the Triassic Falang Formation,Guizhou Province.M. brevis is a relatively large thalattosaurian,with a total length of more than 4 m.The very short snout,with a straight profile,is the most striking of the diagnostic characters of the new taxon.Other diagnostic features include the presence of a crest along the anterodorsal midlines of the premaxillae,the edentulous maxilla,the presence of a groove-like trough along with the anterolateral margin of the maxilla on the ventral surface,the presence of six conical premaxillary teeth,and no more than six conical dentary teeth which are restricted to the anterior portion of the dentary.The absence of the vomer and pterygoid teeth,the anterior shift of the large pineal foramen,and the elongation of the neck indicate that M.brevis may have had a close relationship with the Askeptosauroidea,to which the Chinese genus,Anshunsaurus id referred.