湖北上白垩统马家村组的鸭嘴龙超科新材料(英文)

New hadrosauroid material from the Upper Cretaceous Majiacun Formation of Hubei Province,central China

报道和描述了一些在属级别上不确定的鸭嘴龙超科材料;标本发现于湖北省西北地区与河南交界的淅川盆地西南部的上白垩统马家村组中段。鸭嘴龙超科的骨骼化石和分散的恐龙蛋共存于同一层位,大部分的骨骼化石属于未离巢晚期和幼年早期的个体发育阶段。这一状况可以很好地解释为未离巢和幼年早期阶段的个体与更年老个体所组成的群体之间的地域分隔。通过直接的形态学对比研究,确信可以识别出至少两个鸭嘴龙超科的类群:其中一个类群可能代表了一个相对进步的基干鸭嘴龙类,而另一个类群则很可能归属于鸭嘴龙亚科。鉴于北美鸭嘴龙亚科最早出现的地层时代要更晚,中桑顿期马家村组中段的鸭嘴龙亚科化石材料提供了鸭嘴龙亚科乃至鸭嘴龙科亚洲起源的新证据。

The Xichuan Basin is situated along the northwestern border between Henan and Hubei provinces in central China, and includes a thick accumulation of Upper Cretaceous sediments. Here we report and describe some indeterminate hadrosauroid material on the genus level, which was retrieved from the middle Majiacun Formation （Upper Cretaceous） in the southwestern area of the Xichuan Basin, northwest Hubei. The hadrosauroid remains occur with scattered dinosaur eggs at the same horizon. The majority of the bones may come from the late nestling and early juvenile stages. This condition could be best explained by the geographic segregation of the nestlings and early juveniles from the herd consisting of older individuals, as reported in some hadrosaurids. A minimum of two hadrosauroid taxa are identified through direct morphological comparisons： one may represent a relatively derived non-hadrosaurid hadrosauroid, and the other probably pertains to Hadrosaurinae. Considering the younger age of North American hadrosaurines, the presence of hadrosaurine material within the middle Santonian middle portion of the Majiacun Formation provides new evidence for the Asian origins of both Hadrosaurinae and Hadrosauridae.