DELTAHERPETON HIEMSTRAE, A NEW COLOSTEID TETRAPOD FROM THE MISSISSIPPIAN OF IOWA
DELTAHERPETON HIEMSTRAE, A NEW COLOSTEID TETRAPOD FROM THE MISSISSIPPIAN OF IOWA
复制标题
DOI：
10.1666/10-020.1
复制
发表时间：
2010-11-01
影响因子：
1.4
通讯作者：
Lombard, R. Eric
中科院分区：
文献类型：
--
作者：
Bolt, John R.;Lombard, R. Eric
本文报道了一新的盾甲藻属--三角盾甲藻Deltahopeton hiemstrae gen.et sp. nov.，描述于位于爱荷华州三角洲的密西西比河上游维西恩地区。三角洲赫佩顿的代表是一个头骨屋顶和两个下巴。新的分类群是唯一的colosteids在有一个鼻内和单一的中线后顶。一个额外的中线对cf。可能存在“额间鼻孔”。字符以前用于定义的colosteids进行审查和家庭Colosteidae的精细诊断。将三角蛇鳗属、巨骨鱼属、灰腹蛇鳗属和棘腹蛇鳗属统一为巨骨鱼科的合体象是：前上颌骨有尖牙对;齿骨有容纳前上颌骨尖牙的切迹;下颌骨有单个细长的外颏窗;鼻前眶下侧线终止于外鼻孔正前方的前上颌骨腹侧缘;鼻后眶下侧线止于上颌骨腹侧缘，位于外鼻孔后方。我们的评论真皮骨的colosteid吻的结论是，没有标本是足够免费的扭曲或断裂，以明确表明是否前额叶边界的外鼻孔，或前顶盖存在。Deltahetpeton的形态学和修正后的colosteids数据并没有澄清colosteids与其他早期四足动物的关系。
A new colosteid, Deltahopeton hiemstrae gen. et sp. nov., is described from the Mississippian Upper Visean site at Delta, Iowa. Deltaherpeton is represented by a skull roof and both jaws. The new taxon is unique among colosteids in having an internasal and single midline postparietal. An additional midline pair of cf. `interfrontonasals' may be present. Characters previously used to define the colosteids are reviewed and a refined diagnosis for the family Colosteidae is presented. Synapomorphies which unite Deltaherpeton, Colosteus, Greererpeton, and Pholidogaster as Colosteidae are: premaxilla with fang pair; dentary with notch for receipt of premaxillary fang; mandible with single elongate exomeckelian fenestra; pre-narial infraorbital lateral line terminating at ventral margin of premaxilla just anterior to external naris; and post-narial infraorbital lateral line terminating at the ventral margin of the maxilla just posterior to the external naris. Our review of dermal bones in the colosteid snout concludes that no specimen is sufficiently free of distortions or breakage to indicate clearly whether or not the prefrontal borders the external naris, or that an anterior tectal is present. The morphology of Deltahetpeton and the revised data presented for colosteids do not clarify the relationship of colosteids to other early tetrapods.