Salem Belal S, Lamanna Matthew C, O'Connor Patrick M, El-Qot Gamal M, Shaker Fatma, Thabet Wael A, El-Sayed Sanaa, Sallam Hesham M
Department of Geology, Faculty of Science, Benha University, Benha, Egypt.
Mansoura University Vertebrate Paleontology Center (MUVP), Department of Geology, Faculty of Science, Mansoura University, Mansoura, Egypt.
R Soc Open Sci. 2022 Jun 8;9(6):220106. doi: 10.1098/rsos.220106. eCollection 2022 Jun.
Numerous non-avian theropod dinosaur fossils have been reported from the Upper Cretaceous (Cenomanian) Bahariya Formation, Bahariya Oasis, Western Desert of Egypt, but unambiguous materials of Abelisauridae have yet to be documented. Here we report Mansoura University Vertebrate Paleontology Center (MUVP) specimen 477, an isolated, well-preserved tenth cervical vertebra of a medium-sized abelisaurid from the Bahariya Formation. The new vertebra shows affinities with those of other Upper Cretaceous abelisaurids from Madagascar and South America, such as , , and a generically indeterminate Patagonian specimen (Museo Padre Molina specimen 99). Phylogenetic analysis recovers the Bahariya form within Abelisauridae, either in a polytomy of all included abelisaurids (strict consensus tree) or as an early branching member of the otherwise South American clade Brachyrostra (50% majority rule consensus tree). MUVP 477, therefore, represents the first confirmed abelisaurid fossil from the Bahariya Formation and the oldest definitive record of the clade from Egypt and northeastern Africa more generally. The new vertebra demonstrates the wide geographical distribution of Abelisauridae across North Africa during the middle Cretaceous and augments the already extraordinarily diverse large-bodied theropod assemblage of the Bahariya Formation, a record that also includes representatives of Spinosauridae, Carcharodontosauridae and Bahariasauridae.
在埃及西部沙漠巴哈里亚绿洲的上白垩统（森诺曼阶）巴哈里亚组中，已报道了大量非鸟恐龙化石，但阿贝力龙科的确切化石材料尚未被记录。在此，我们报道曼苏拉大学脊椎动物古生物学中心（MUVP）标本477，它是来自巴哈里亚组的一具保存完好的中型阿贝力龙科的孤立第十颈椎。这枚新颈椎与马达加斯加和南美洲的其他上白垩统阿贝力龙科恐龙的颈椎具有相似性，例如 、 、 以及一个属种未定的巴塔哥尼亚标本（莫利纳神父博物馆标本99）。系统发育分析将巴哈里亚组的化石归入阿贝力龙科，在所有包含的阿贝力龙科恐龙的多歧分支（严格合意树）中，或者作为南美洲短吻类分支（50%多数规则合意树）的一个早期分支成员。因此，MUVP 477代表了巴哈里亚组中首个经确认的阿贝力龙科化石，也是埃及乃至更广泛的东北非地区该类群最古老的确切记录。这枚新颈椎表明，在白垩纪中期阿贝力龙科在北非广泛分布，同时也丰富了巴哈里亚组本就异常多样的大型兽脚类恐龙组合，该组合还包括棘龙科、鲨齿龙科和巴哈里亚龙科的代表。
