Retrodeformation and muscular reconstruction of ornithomimosaurian dinosaur crania
Retrodeformation and muscular reconstruction of ornithomimosaurian dinosaur crania
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DOI：
10.7717/peerj.1093
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发表时间：
2015-07-09
期刊：
影响因子：
2.7
通讯作者：
Rayfield, Emily J.
中科院分区：
文献类型：
--
作者：
Cuff, Andrew R.;Rayfield, Emily J.
鸟龙类恐龙进化出了重量轻、无齿的头骨，拥有角质的喙鞘。了解这些分类群的解剖结构可以更好地了解“鸵鸟模仿”恐龙和兽脚亚目恐龙进化过程中的性格变化。然而，埋藏过程中的泥化作用往往扭曲化石遗迹。逆向变形提供了一种恢复标本原始解剖结构假设的方法，3D扫描技术提供了一种约束和记录逆向变形过程的方法。使用计算机断层扫描（CT）扫描数据，标本特定的retrodeformations进行三维保存，但taphonomically扭曲的头骨deinocheirid Garudimimus brevipes Barsbold，1981年和ornithomimids Struthiomimus altus Lambe，1902年和Ornithomimus edmontonicus斯滕贝格，1933年。这允许重建内收肌肌肉组织，然后将其映射到颅骨上，从中计算向后变形前后的肌肉机械优势和咬合力。rhamphotheca的程度是不同的，在每一个分类群，以代表现代鸟类内发现的形态。良好的约束retrodeformation允许增加化石标本的解剖和功能分析的信心，并提供了一个机会，以更充分地了解软组织解剖灭绝类群。
Ornithomimosaur dinosaurs evolved lightweight, edentulous skulls that possessed keratinous rhamphothecae. Understanding the anatomy of these taxa allows for a greater understanding of "ostrich-mimic" dinosaurs and character change during theropod dinosaur evolution. However, taphonomic processes during fossilisation often distort fossil remains. Retrodeformation offers a means by which to recover a hypothesis of the original anatomy of the specimen, and 3D scanning technologies present a way to constrain and document the retrodeformation process. Using computed tomography (CT) scan data, specimen specific retrodeformations were performed on three-dimensionally preserved but taphonomically distorted skulls of the deinocheirid Garudimimus brevipes Barsbold, 1981 and the ornithomimids Struthiomimus altus Lambe, 1902 and Ornithomimus edmontonicus Sternberg, 1933. This allowed for a reconstruction of the adductor musculature, which was then mapped onto the crania, from which muscle mechanical advantage and bite forces were calculated pre- and post-retrodeformation. The extent of the rhamphotheca was varied in each taxon to represent morphologies found within modern Aves. Well constrained retrodeformation allows for increased confidence in anatomical and functional analysis of fossil specimens and offers an opportunity to more fully understand the soft tissue anatomy of extinct taxa.