The Gobiosuchidae in the early evolution of Crocodyliformes

The anatomy and phylogenetic relationships of the Las Hoyas gobiosuchid (upper Barremian, La Huérguina Formation, Cuenca, Spain) are discussed on the basis of two fully articulated specimens. Phylogenetic analysis supports the monophyly of Gobiosuchidae, defined by the Las Hoyas taxon, <i>Cassissuchus sanziuami</i>, gen. et sp. nov., as the sister taxon of the Asian clade <i>Gobiosuchus</i> + <i>Zaraasuchus</i>. The family Gobiosuchidae is diagnosed by a large number of synapomorphies, such as the presence of extensively sutured palpebrals, ridges on the dorsal surface of the posterolateral region of the squamosal, a longitudinal ridge along the dorsolateral surface of the surangular, appendicular osteoderms, and closure of the supratemporal fenestra. Specimens attributed to <i>Lisboasaurus estesi</i>, a putative gobiosuchid, are evaluated and the taxon regarded as a nomen dubium. <i>Cassissuchus sanziuami</i> provides new evidence on the anatomy of the pectoral and pelvic girdles and the forelimb morphology in Gobiosuchidae. The phylogeny of basal Crocodyliformes supports the nested sequence of three clades: Protosuchidae, Gobiosuchidae, and ((<i>Shantungosuchus</i> + <i>Sichuanosuchus</i>) + Shartegosuchidae), but their interrelationships are only partially solved. The early evolution of Crocodyliformes is further characterized by the high number of phenotypic specializations, many of which are related to the dermal skeletal overgrowth of the temporal region, palpebrals, and osteoderms. http://zoobank.org/urn:lsid:zoobank.org:pub:5317CCDB-FA28-4748-9712-1BC27A166108 SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP Citation for this article: Buscalioni, Á. D. 2017. The Gobiosuchidae in the early evolution of Crocodyliformes. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1324459.

本文基于两件完全关联保存的标本，对产自西班牙昆卡省拉韦尔吉纳组（La Huérguina Formation）上巴列姆阶（Barremian）的拉斯霍亚斯（Las Hoyas）戈壁鳄类的解剖结构与系统发育关系展开讨论。

系统发育分析支持戈壁鳄科（Gobiosuchidae）为单系群，该科以产自拉斯霍亚斯的新属新种*Cassissuchus sanziuami*（gen. et sp. nov.）为定义类群，其与亚洲分支*Gobiosuchus*（戈壁鳄属）+*Zaraasuchus*（扎拉鳄属）构成姊妹群。

戈壁鳄科可通过大量共有衍征（synapomorphies）进行鉴定，包括广泛缝合的眼睑骨（palpebrals）、鳞骨（squamosal）后外侧区域背侧表面的嵴、沿上隅骨（surangular）背外侧表面延伸的纵嵴、附肢皮内成骨（appendicular osteoderms），以及颞上孔（supratemporal fenestra）闭合。

对被归入疑似戈壁鳄科类群*Lisboasaurus estesi*（埃斯特斯里斯本鳄）的标本进行重新评估后，该分类单元被视为疑名（nomen dubium）。

*Cassissuchus sanziuami*为戈壁鳄科的肩带（pectoral girdles）、腰带（pelvic girdles）及前肢形态研究提供了新的解剖学证据。

基干鳄形类（Crocodyliformes）的系统发育关系支持三个分支的嵌套序列：原鳄科（Protosuchidae）、戈壁鳄科，以及（（*Shantungosuchus*（山东鳄属）+*Sichuanosuchus*（四川鳄属））+沙特鳄科（Shartegosuchidae）），但三者之间的具体亲缘关系仅部分得到解析。

鳄形类的早期演化还表现出大量的特化表型特征，其中多数与颞区、眼睑骨及皮内成骨的真皮骨骼过度发育相关。

http://zoobank.org/urn:lsid:zoobank.org:pub:5317CCDB-FA28-4748-9712-1BC27A166108

补充数据——本文的补充材料可通过www.tandfonline.com/UJVP免费获取

本文引用格式：Buscalioni, Á. D. 2017. 《鳄形类早期演化中的戈壁鳄科》. 《脊椎动物古生物学杂志》（Journal of Vertebrate Paleontology）. DOI: 10.1080/02724634.2017.1324459.