The skull of Sanajeh indicus , a Cretaceous snake with an upper temporal bar, and the origin of ophidian wide-gaped feeding
The skull of Sanajeh indicus , a Cretaceous snake with an upper temporal bar, and the origin of ophidian wide-gaped feeding
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Sanajeh indicus 的头骨，一种白垩纪蛇，有上颞条，以及蛇类大口进食的起源
DOI：
10.1093/zoolinnean/zlac001
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发表时间：
2022
影响因子：
2.8
通讯作者：
Wilson Mantilla, Jeffrey A.
中科院分区：
文献类型：
--
作者：
Zaher, Hussam;Mohabey, Dhananjay M.;Grazziotin, Felipe G.;Wilson Mantilla, Jeffrey A.
最近的系统发育分析对蛇的起源和相互关系的解释存在分歧，导致对蛇的生态学、习性和与大口进食相关的特征获得的观点两极分化。在这里，我们报告了一个新的白垩纪晚期巢穴捕食者sanajeh indicus的标本，这有助于解决大造口术的起源。这个新标本保留了一个骨化的上颞骨和一个向后扩张的耳枕区，该区域缺乏自由的颞上骨，并保留了一个类似蜥蜴的腭颌弓，允许吞咽时有限的运动。一个大规模的全证据数据集的系统发育分析表明，在Pan-Serpentes的基础上，anajeh是najash、dinilysia和冠群Serpentes的姊妹类群。白垩纪的步足蛇和针叶蛇是泛蛇纲中分化最早的成员。白垩纪的后肢厚鼻目和新生代澳大利亚的“madtsoids”属于冠状硬鼻目，而mosasaur则总是属于anguimorphs。我们的研究结果表明，沧龙和蛇的宽口条件可能是独立进化的，作为功能上不同的猎物摄取机制。保存下来的中间形态表明，在巨噬动物、新生代澳大利亚“madtsoids”和alethinophidians的共同祖先中，巨噬动物在进食大型猎物（巨噬）之前就开始了宽口、单侧进食（大造口），这一行为出现在35万年前。
Recent phylogenetic analyses differ in their interpretations of the origin and interrelationships of snakes, resulting in polarized views of snake ecology, habit and acquisition of features associated with wide-gaped feeding (macrostomy). Here, we report a new specimen of the Late Cretaceous nest predatorSanajeh indicusthat helps to resolve the origin of macrostomy. The new specimen preserves an ossified upper temporal bar and a posteriorly expanded otooccipital region that lacks a free-ending supratemporal bone and retains a lizard-like palatomaxillary arch that allows limited movements during swallowing. Phylogenetic analyses of a large-scale total evidence dataset resolveSanajehnear the base of Pan-Serpentes, as the sister group ofNajash,Dinilysiaand crown-group Serpentes. The CretaceousTetrapodophisandConiophisrepresent the earliest-diverging members of Pan-Serpentes. The Cretaceous hindlimbed pachyophiids and Cenozoic Australian ‘madtsoiids’ are inside crown Alethinophidia, whereas mosasaurs are recovered invariably within anguimorphs. Our results suggest that the wide-gape condition in mosasaurs and snakes might have evolved independently, as functionally distinct mechanisms of prey ingestion. The intermediate morphology preserved inSanajehindicates that ingestion of large prey items (macrophagy) preceded wide-gaped, unilateral feeding (macrostomy), which appeared 35 Myr later, in the common ancestor of pachyophiids, Cenozoic Australian ‘madtsoiids’ and alethinophidians.