Département Origine et Evolution, UMR 7207, Centre de recherche en Paléontologie, CNR/Sorbonne Université/MNHN, Muséum national d'Histoire naturelle, Paris, France.
Department of Natural History, Florida Museum of Natural History, University of Florida, Gainesville, FL, United States of America.
PeerJ. 2022 Jul 15;10:e13699. doi: 10.7717/peerj.13699. eCollection 2022.
Neobatrachia, a clade representing the majority of extant anuran diversity, is thought to have emerged and diversified during the Cretaceous. Most of the early diversification of neobatrachians occurred in southern Gondwana, especially the regions that are today South America and Africa. Whereas five extinct neobatrachians have been described from the Cretaceous of South America in the last decade, only one is known from Africa. This difference in the known extinct diversity is linked to the lack of well-preserved specimens, understudy of fragmentary remains, and lack of known Cretaceous sites in Africa. Study of fragmentary anuran remains from Africa could allow for the identification of previously unknown neobatrachians, allowing for a better understanding of their early diversification. We reanalysed several previously described anuran specimens from the well-known Kem Kem beds, including using CT-scanning. Through our osteological study, we determined that several cranial bones and vertebrae represent a new hyperossified taxon for which we provide a formal description. Comparison to other hyperossified anurans revealed similarities and affinity of this new taxon with the neobatrachians (extinct) and (extant). Phylogenetic analyses supported this affinity, placing the new taxon within Neobatrachia in an unresolved clade of Ceratophryidae. This taxon is the oldest neobatrachian from Africa, and reveals that neobatrachians were already widespread throughout southern Gondwana during the earliest Late Cretaceous.
新蛙类，代表了现存有尾目多样性的大多数，被认为是在白垩纪出现和多样化的。新蛙类的早期多样化主要发生在冈瓦纳大陆的南部，尤其是今天的南美洲和非洲地区。在过去十年中，已经从南美洲的白垩纪描述了五个灭绝的新蛙类，而在非洲只有一个。这种已知灭绝多样性的差异与缺乏保存完好的标本、对破碎遗骸的研究不足以及非洲缺乏已知的白垩纪遗址有关。对来自非洲的有尾类破碎遗骸的研究可以识别以前未知的新蛙类，从而更好地了解它们的早期多样化。我们重新分析了来自著名的 Kem Kem 地层的几个以前描述的有尾类标本，包括使用 CT 扫描。通过我们的骨骼研究，我们确定了几个颅骨和脊椎骨代表了一个新的骨质增生分类群，我们为此提供了正式的描述。与其他骨质增生的有尾类进行比较表明，这个新的分类群与新蛙类（灭绝）和（现存）有相似性和亲和力。系统发育分析支持这种亲和力，将新的分类群置于未解决的角蟾科 Neobatrachia 内。这个分类群是来自非洲最古老的新蛙类，它表明在最早的晚白垩世，新蛙类已经在冈瓦纳大陆的南部广泛分布。
