Anné Jennifer, Whitney Megan, Brocklehurst Robert, Donnelly Kevin, Rothschild Bruce
The Children's Museum of Indianapolis, Indianapolis, Indiana, USA.
Harvard Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA.
Anat Rec (Hoboken). 2023 Mar;306(3):594-606. doi: 10.1002/ar.25078. Epub 2022 Sep 21.
The study of pathologies in the fossil record allows for unique insights into the physiology, immunology, biomechanics, and daily life history of extinct organisms. This is especially important in organisms that have body structures dissimilar to those of extant organisms as well as transitional groups whose extant relatives may have very dissimilar physiologies. Comparisons between modern groups and their fossil ancestors are further complicated by the fact that fossil groups may have experienced unique biomechanical stresses as well as possessing a mixture of anatomical features seen in their related extant groups. In this study, we present lesions in the caudal vertebrae of the hadrosaur, Edmontosaurus annectens from the Ruth Mason Dinosaur Quarry of South Dakota, which exhibit unique morphologies. X-ray microtomography was performed on the most extreme example of this morphology to allow for both a detailed and more accurate diagnosis of the pathologic condition as well as virtual conservation of the specimen. Based on the location, the overall morphology of the lesion, and the relative "normal" appearance of the internal microstructure, the most probable cause is postulated as long-term biomechanical stresses exerted on this section of the tail by both lateral and dorsoventral motions of the tail. This deduction was based on a process of elimination for a variety of known osteological conditions; however, future work is needed to determine the nature of the stresses and why this condition has not been recorded in more hadrosaurian specimens.
对化石记录中的病理学研究能够让我们对已灭绝生物的生理学、免疫学、生物力学及日常生活史有独特的见解。这对于那些身体结构与现存生物不同的生物，以及其现存亲属生理机能可能差异极大的过渡类群来说尤为重要。现代类群与其化石祖先之间的比较因以下事实而变得更加复杂：化石类群可能经历了独特的生物力学压力，并且拥有其相关现存类群中所见到的混合解剖特征。在本研究中，我们展示了来自南达科他州露丝·梅森恐龙采石场的鸭嘴龙（埃德蒙顿龙）尾椎中的病变，这些病变呈现出独特的形态。对这种形态的最极端例子进行了X射线显微断层扫描，以便对病理状况进行详细且更准确的诊断，并对标本进行虚拟保存。基于病变的位置、整体形态以及内部微观结构的相对“正常”外观，最可能的原因被假定为尾巴的侧向和背腹向运动对尾巴这一部分施加的长期生物力学压力。这一推断是基于对各种已知骨学状况的排除过程得出的；然而，未来还需要开展工作来确定压力的性质以及为何在更多的鸭嘴龙标本中未记录到这种情况。
