A new peculiar dinosaur egg, Sankofa pyrenaica oogen. nov oosp nov from the Upper Cretaceous coastal deposits of the Aren Formation, south-central Pyrenees, Lleida, Catalonia, Spain
A new peculiar dinosaur egg, Sankofa pyrenaica oogen. nov oosp nov from the Upper Cretaceous coastal deposits of the Aren Formation, south-central Pyrenees, Lleida, Catalonia, Spain
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DOI：
10.1111/j.1475-4983.2011.01114.x
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发表时间：
2012-03-01
期刊：
影响因子：
2.6
通讯作者：
Vicens, Enric
中科院分区：
文献类型：
--
作者：
Lopez-Martinez, Nieves;Vicens, Enric
一种新型的小型卵形恐龙蛋，Sankofa pyrenaica oogen。11月十一月，在西班牙加泰罗尼亚莱利达南比利牛斯中央单元Montsec地区的上白垩纪（上坎帕尼亚-马斯特里赫特阶）沉积物中描述了一种具有棱柱型蛋壳的化石。这种蛋型是在亚垂直奠定了只有两个丰富的单种网站的一个单一的地层从沿海沉积的阿伦组，解释为一个出现的海滩脊障壁岛泻湖沉积体系。这些蛋的大小和形状及其不对称的两极与现代鸡蛋大致相似，这在白垩纪的化石蛋记录中是不寻常的。其系统发育位置与鸟类和伤齿龙类卵相似。对蛋形状的形态空间分析显示，新蛋与阿根廷的坎帕尼亚鸟蛋化石相似，两者都介于现代鸟蛋和已灭绝的兽脚亚目恐龙蛋之间。然而，Sankofa pyrenaica的蛋壳微结构不同于鸟蛋，在其初始鳞片纹理。它在栅栏层的中间有一种特殊的连锁小晶体图案，而不是现代鸟类蛋壳中常见的厚鳞状结构。这种新的蛋类型是由于一个小兽脚类恐龙，可能与一个单一的输卵管一样的鸟类和马赛克分布的功能是鸟类和nonavian兽脚类恐龙之间的组合。这增强了支持两个群体之间密切的系统发育关系的论据。
A new type of small, ovoid dinosaur egg, Sankofa pyrenaica oogen. nov. oosp. nov., with a prismatic type eggshell is described from upper Cretaceous (upper CampanianMaastrichtian) deposits of the Montsec area, South Pyrenean Central Unit, Lleida, Catalonia, Spain. This egg type was sub-vertically laid in only two rich monospecific sites of a single stratigraphic layer from coastal deposits of the Aren Formation, interpreted as an emerged beach ridge of a barrier island lagoon depositional system. The size and shape of these eggs with their asymmetric poles are roughly similar to modern hen eggs, which is unusual in the Cretaceous fossil egg record. Its phylogenetic position clusters with bird and Troodontid eggs. A morphospace analysis of egg shapes shows the similarity of the new egg to a Campanian fossil bird egg from Argentina, both being intermediate between modern-bird eggs and extinct nonavian theropod eggs. However, the eggshell microstructure of Sankofa pyrenaica differs from that of bird eggs in its incipient squamatic texture. It has a peculiar pattern of interlocking small crystals in the middle of the palisade layer, instead of the thick squamatic structure commonly present in modern avian eggshells. This new egg type is attributed to a small theropod, probably with a single oviduct like birds and whose mosaic distribution of features is a combination between that of birds and nonavian theropods. This enhances the arguments supporting the close phylogenetic relationships between both groups.