Williams Cariad J, Pani Martino, Bucchi Andrea, Smith Roy E, Kao Alexander, Keeble William, Ibrahim Nizar, Martill David M
School of the Environment, Geography and Geosciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth, PO1 3QL, UK.
Center for Paleontology, Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, Forbes Natural History Building 1816 S. Oak Street, Champaign, IL 61820, USA.
iScience. 2021 Apr 14;24(4):102338. doi: 10.1016/j.isci.2021.102338. eCollection 2021 Apr 23.
Azhdarchid pterosaurs, the largest flying vertebrates, remain poorly understood, with fundamental aspects of their palaeobiology unknown. X-ray computed tomography reveals a complex internal micro-architecture for three-dimensionally preserved, hyper-elongate cervical vertebrae of the Cretaceous azhdarchid pterosaur, sp. Incorporation of the neural canal within the body of the vertebra and elongation of the centrum result in a "tube within a tube" supported by helically distributed trabeculae. Linear elastic static analysis and linearized buckling analysis, accompanied with a finite element model, reveal that as few as 50 trabeculae increase the buckling load by up to 90%, implying that a vertebra without the trabeculae is more prone to elastic instability due to axial loads. Subsuming the neural tube into the centrum tube adds considerable stiffness to the cervical series, permitting the uptake of heavy prey items without risking damage to the cervical series, while at the same time allowing considerable skeletal mass reduction.
阿氏翼龙是最大的飞行脊椎动物，人们对它们的了解仍然很少，其古生物学的基本方面尚不清楚。X射线计算机断层扫描揭示了白垩纪阿氏翼龙三维保存的超长颈椎的复杂内部微观结构。神经管道并入椎体主体以及椎体延长，形成了由螺旋分布的小梁支撑的“管中管”结构。线性弹性静力分析和线性化屈曲分析以及有限元模型表明，仅50根小梁就能使屈曲载荷增加高达90%，这意味着没有小梁的椎体更容易因轴向载荷而产生弹性不稳定。将神经管并入椎体管增加了颈椎系列的相当大的刚度，使得能够捕食较重的猎物而不会有损伤颈椎系列的风险，同时还能大幅减轻骨骼质量。
