Bone histology indicates insular dwarfism in a new Late Jurassic sauropod dinosaur
Bone histology indicates insular dwarfism in a new Late Jurassic sauropod dinosaur
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DOI：
10.1038/nature04633
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发表时间：
2006-06
期刊：
影响因子：
64.8
通讯作者：
P. Sander;O. Mateus;T. Laven;Nils Knötschke
中科院分区：
文献类型：
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作者：
P. Sander;O. Mateus;T. Laven;Nils Knötschke
蜥脚类恐龙是有史以来居住在陆地上的最大的动物，至少有三个谱系的真正巨大的形式，。成年体质量小于5吨的小型物种非常罕见，小型蜥脚类恐龙的骨骼通常代表幼年体。在这里，我们描述了一个新的小型物种的基础macronarian蜥脚类，欧罗巴龙holgerigen。et sp. nov.，根据骨骼组织学，我们发现它是一个侏儒物种。这些化石来自于北方德国的Kimmeridgian海床，记录了11个以上的蜥脚类恐龙个体，全长1.7 ~ 6.2 m。部分骨骼和孤立的骨骼之间的形态重叠链接所有材料相同的新taxon. Cortex组织学股骨和胫骨标本内的大小差异是由于不同的个体发育阶段，从少年到完全成长的个人。这些小恐龙一定生活在下萨克森盆地周围的一个大岛上。与大型蜥脚类动物的长骨组织学比较表明，岛屿侏儒物种是通过其较大祖先的生长速度下降而进化而来的。
Sauropod dinosaurs were the largest animals ever to inhabit the land, with truly gigantic forms in at least three lineages,,. Small species with an adult body mass less than five tonnes are very rare,, and small sauropod bones generally represent juveniles. Here we describe a new diminutive species of basal macronarian sauropod,Europasaurus holgerigen. et sp. nov., and on the basis of bone histology we show it to have been a dwarf species. The fossils, including excellent skull material, come from Kimmeridgian marine beds of northern Germany,, and record more than 11 individuals of sauropods 1.7 to 6.2 m in total body length. Morphological overlap between partial skeletons and isolated bones links all material to the same new taxon. Cortical histology of femora and tibiae indicates that size differences within the specimens are due to different ontogenetic stages, from juveniles to fully grown individuals. The little dinosaurs must have lived on one of the large islands around the Lower Saxony basin. Comparison with the long-bone histology of large-bodied sauropods suggests that the island dwarf species evolved through a decrease in growth rate from its larger ancestor.