A new eusuchian crocodyliform with novel cranial integument and its significance for the origin and evolution of Crocodylia.
A new eusuchian crocodyliform with novel cranial integument and its significance for the origin and evolution of Crocodylia.
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DOI：
10.1371/journal.pone.0030471
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Gardner NM
中科院分区：
文献类型：
--
作者：
Holliday CM;Gardner NM
鳄形目是中生代四足动物中最成功的类群之一，分布于陆地、半水生和海洋环境，同时占据了许多营养生态位，包括食肉、食虫、食草和食鱼物种。在这些分类群中，有一种产于北方非洲白垩纪晚期的平头鳄形类，它们神秘莫测，代表性不强。在这里，我们报告了一个新的，巨大的鳄鱼从早期晚白垩世（Cenomanian）Kem Kem组的摩洛哥。该分类群以部分脑壳为代表，有一个极长、扁平的头骨，有大的下颚和颅颈肌。头骨顶部有脊状突起，有一个宽阔粗糙的隆起，周围有明显的血管印记，可能形成了鳄形目动物中独特的表皮结构。使用颅内容积估计的大小表明标本非常大。该分类群具有强壮的侧蝶，具有侧向定向的头状突起和孤立的上翼，其特征使其与衍生的真鳄类结盟。系统发育分析发现，该分类群是一个衍生的尤苏克和姐妹分类群的埃及鳄，一个知之甚少，早期晚白垩世分类群从Bahariya形成。这个分支形成了冠群Crocodylia的姐妹分支，使这些分类群成为非洲已知的最早的优苏克鳄形类。这些结果转移系统发育和地理学的假设对环特提斯地区的现代鳄鱼的起源，并提供了重要的新数据，Eusuchian形态和进化。
Crocodyliforms were one of the most successful groups of Mesozoic tetrapods, radiating into terrestrial, semiaquatic and marine environments, while occupying numerous trophic niches, including carnivorous, insectivorous, herbivorous, and piscivorous species. Among these taxa were the enigmatic, poorly represented flat-headed crocodyliforms from the late Cretaceous of northern Africa. Here we report a new, giant crocodyliform from the early Late Cretaceous (Cenomanian) Kem Kem Formation of Morocco. Represented by a partial braincase, the taxon has an extremely long, flat skull with large jaw and craniocervical muscles. The skull roof is ridged and ornamented with a broad, rough boss surrounded by significant vascular impressions, likely forming an integumentary structure unique among crocodyliforms. Size estimates using endocranial volume indicate the specimen was very large. The taxon possesses robust laterosphenoids with laterally oriented capitate processes and isolated epipterygoids, features allying it with derived eusuchians. Phylogenetic analysis finds the taxon to be a derived eusuchian and sister taxon to Aegyptosuchus, a poorly understood, early Late Cretaceous taxon from the Bahariya formation. This clade forms the sister clade of crown-group Crocodylia, making these taxa the earliest eusuchian crocodyliforms known from Africa. These results shift phylogenetic and biogeographical hypotheses on the origin of modern crocodylians towards the circum-Tethyean region and provide important new data on eusuchian morphology and evolution.
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DOI：
10.1111/j.1096-3642.2007.00315.x
发表时间：
2007-08-01
影响因子：
2.8
作者：
Brochu, Christopher A.
通讯作者：
Brochu, Christopher A.
影响因子：
3.7
作者：
Ibrahim N;Unwin DM;Martill DM;Baidder L;Zouhri S
通讯作者：
Zouhri S
影响因子：
1.4
作者：
Abdala, F;Hancox, PJ;Neveling, J
通讯作者：
Neveling, J
DOI：
10.1111/j.1096-0031.1994.tb00179.x
发表时间：
1994-09-01
期刊：
CLADISTICS-THE INTERNATIONAL JOURNAL OF THE WILLI HENNIG SOCIETY
影响因子：
--
作者：
BREMER, K
通讯作者：
BREMER, K
影响因子：
2.6
作者：
Aguilera, Orangel A.;Riff, Douglas
通讯作者：
Riff, Douglas