Bone histology of the titanosaur Lirainosaurus astibiae (Dinosauria: Sauropoda) from the Latest Cretaceous of Spain
Bone histology of the titanosaur Lirainosaurus astibiae (Dinosauria: Sauropoda) from the Latest Cretaceous of Spain
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DOI：
10.1007/s00114-010-0742-3
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发表时间：
2011-01-01
影响因子：
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通讯作者：
Company, Julio
中科院分区：
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作者：
Company, Julio
雷龙是伊比利亚半岛白垩纪晚期唯一已知的蜥脚类动物。利龙的体型并不庞大，是迄今为止发现的最小的蜥脚类动物之一。对利龙龙骨骼进行组织学分析，重点研究了其附属物的骨干横切面，结果表明利龙龙没有表现出大型蜥脚类恐龙典型的骨骼微观结构，但与同时期的三juanalamosaurus sanjuanensis， Ampelosaurus atacis和Magyarosaurus dacus相当，并且与其他中小型蜥脚类恐龙具有相同的组织学特征。龙的四肢骨骼呈现出一种被生长痕迹打断的层状纤维层状骨微观结构，在成年期被强烈的二次重塑过程完全抹去，这种重塑过程倾向于完全取代初级皮层。利龙的体型比典型的蜥脚类恐龙要小，这降低了初级骨膜成骨的速度，并在达到成年体型之前就开始了广泛的二次重塑。在相似的个体发育阶段，利龙长骨的组织学组织比基础的新蜥脚类动物更成熟，记录了一个由预移位引起的过变形的案例。这种异速生长可能逆转了蜥脚类动物谱系中典型的加速骨沉积模式。
The titanosaur Lirainosaurus astibiae is the only sauropod species known from the Late Cretaceous of the Iberian Peninsula. Lirainosaurus did not reach a gigantic body size and is one of the smallest sauropods discovered to date. Histological analysis of Lirainosaurus bones, focused on diaphyseal transverse sections of appendicular elements, reveals that Lirainosaurus did not exhibit the osseous microstructure typical for large sauropods, but is comparable with that of the coeval titanosaurs Alamosaurus sanjuanensis, Ampelosaurus atacis, and Magyarosaurus dacus, and also shares histological traits with other small to medium-sized sauropodomorph dinosaurs. Lirainosaurus limb bones exhibit a laminar fibrolamellar bone microstructure interrupted by growth marks, fully obliterated in adulthood by intense secondary remodeling processes which tend to replace completely the primary cortex. Lirainosaurus attained smaller sizes than typical sauropods reducing the rate of primary periosteal osteogenesis and developing an extensive secondary remodeling well before the adult size was reached. Histological organization of Lirainosaurus long bones is more mature than observed in basal neosauropods at similar ontogenetic stage, documenting a case of peramorphosis by pre-displacement. This heterochronic growth would be a reversal of the accelerated pattern of bone deposition typical for the sauropod lineage.