The braincase, brain and palaeobiology of the basal sauropodomorph dinosaur Thecodontosaurus antiquus
The braincase, brain and palaeobiology of the basal sauropodomorph dinosaur Thecodontosaurus antiquus
复制标题
DOI：
10.1093/zoolinnean/zlaa157
复制
发表时间：
2021-10-01
影响因子：
2.8
通讯作者：
Benton, Michael J.
中科院分区：
文献类型：
--
作者：
Ballell, Antonio;King, J. Logan;Benton, Michael J.
蜥脚龙在整个进化过程中在解剖和生态方面经历了巨大的变化。晚三叠世古齿龙在蜥脚亚目中占有基础地位，是记录这些形态功能转变如何发生的关键分类单元。在这里，我们重新描述了脑壳骨学，并基于计算机断层扫描数据重建了齿龙的神经解剖学。齿龙的脑壳具有基底结节的内侧基枕部分和与其他基足突形态相同的U型基枕-副蝶骨缝合，并显示出明显的特征组合：脑底轮廓笔直，有一个完整的转位孔，一个未骨化的间隙，大的绒毛状窝，侧位垂直于丘状突起的蝶骨突起和一个菱形的枕大孔。根据恐龙解剖学的新发现，我们重新解释了这些脑壳特征。我们的内颅骨重建揭示了齿龙古生物学的重要方面，支持两足动物的站姿和屈体习惯，并适应了在移动时保持稳定的头部和凝视。我们还根据骨内迷路的形态估计了它的听力频率和范围。我们的研究提供了新的信息，在脑壳和内颅骨进化的模式，在南美龙虾。
Sauropodomorph dinosaurs underwent drastic changes in their anatomy and ecology throughout their evolution. The Late Triassic Thecodontosaurus antiquus occupies a basal position within Sauropodomorpha, being a key taxon for documenting how those morphofunctional transitions occurred. Here, we redescribe the braincase osteology and reconstruct the neuroanatomy of Thecodontosaurus, based on computed tomography data. The braincase of Thecodontosaurus shares the presence of medial basioccipital components of the basal tubera and a U-shaped basioccipital-parabasisphenoid suture with other basal sauropodomorphs and shows a distinct combination of characters: a straight outline of the braincase floor, an undivided metotic foramen, an unossified gap, large floccular fossae, basipterygoid processes perpendicular to the cultriform process in lateral view and a rhomboid foramen magnum. We reinterpret these braincase features in the light of new discoveries in dinosaur anatomy. Our endocranial reconstruction reveals important aspects of the palaeobiology of Thecodontosaurus, supporting a bipedal stance and cursorial habits, with adaptations to retain a steady head and gaze while moving. We also estimate its hearing frequency and range based on endosseous labyrinth morphology. Our study provides new information on the pattern of braincase and endocranial evolution in Sauropodomorpha.