Locomotion in ornithischian dinosaurs: an assessment using three-dimensional computational modelling.
Locomotion in ornithischian dinosaurs: an assessment using three-dimensional computational modelling.
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鸟臀目恐龙的运动：使用三维计算模型的评估。
DOI：
10.1111/brv.12071
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发表时间：
2014
影响因子：
--
通讯作者：
Maidment SC
中科院分区：
文献类型：
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作者：
Maidment SC
鸟臀目恐龙是两足动物，前肢为抓握而改变，但四足动物在进化支中至少有三次独立进化。除了鸟臀目之外，从两足祖先进化而来的四足动物只在另外两个场合进化过，这是四足动物进化史上最罕见的运动转变之一。与这些转变相关的骨骼学和肌肉学变化最近才被记录下来，这些变化的生物力学后果仍有待研究。在这里，我们回顾了以前理解灭绝动物运动的方法，这些方法可以大致分为基于现存动物的类比的形式功能方法，肢体骨骼缩放和计算方法。然后，我们首次系统地尝试量化两足和四足鸟臀目恐龙运动肌肉功能的变化。使用主要骨盆运动肌肉力矩臂的三维计算模型，我们研究了个体分类群之间，四足和双足分类群之间，以及代表三个主要鸟臀目谱系（Thyreophora，Ornithopoda，Marginocephalia）的分类群之间的相似性和差异。我们的研究结果表明，角鼻龙Chasmosaurus和ornithopodHypsilophodon有相对较低的力矩臂的大多数肌肉和大多数功能，也许表明这些类群的运动性能差。四足动物有较高的外展肌力矩臂比两足动物，我们认为这是由于整体更广泛的机构的四足动物建模。四足动物的伸肌力臂在髋关节角度更大时达到峰值，而内侧旋转力臂比两足动物低，这可能是由于四足动物的后肢柱状更明显，内侧旋转作为一种外侧肢体支撑形式而丧失。我们不能确定整个鸟臀目的力臂进化趋势，这表明鸟臀目的两足祖先并没有通过有限数量的功能途径限制四足运动的发展。功能解剖学似乎对力矩臂的影响比进化更大，并且在个体分类群和个体分支之间确定的差异可能与生活在不同环境中或分支特异性行为所需的运动性能的差异有关。
Ornithischian dinosaurs were primitively bipedal with forelimbs modified for grasping, but quadrupedalism evolved in the clade on at least three occasions independently. Outside of Ornithischia, quadrupedality from bipedal ancestors has only evolved on two other occasions, making this one of the rarest locomotory transitions in tetrapod evolutionary history. The osteological and myological changes associated with these transitions have only recently been documented, and the biomechanical consequences of these changes remain to be examined. Here, we review previous approaches to understanding locomotion in extinct animals, which can be broadly split into form–function approaches using analogy based on extant animals, limb‐bone scaling, and computational approaches. We then carry out the first systematic attempt to quantify changes in locomotor muscle function in bipedal and quadrupedal ornithischian dinosaurs. Using three‐dimensional computational modelling of the major pelvic locomotor muscle moment arms, we examine similarities and differences among individual taxa, between quadrupedal and bipedal taxa, and among taxa representing the three major ornithischian lineages (Thyreophora, Ornithopoda, Marginocephalia). Our results suggest that the ceratopsidChasmosaurusand the ornithopodHypsilophodonhave relatively low moment arms for most muscles and most functions, perhaps suggesting poor locomotor performance in these taxa. Quadrupeds have higher abductor moment arms than bipeds, which we suggest is due to the overall wider bodies of the quadrupeds modelled. A peak in extensor moment arms at more extended hip angles and lower medial rotator moment arms in quadrupeds than in bipeds may be due to a more columnar hindlimb and loss of medial rotation as a form of lateral limb support in quadrupeds. We are not able to identify trends in moment arm evolution across Ornithischia as a whole, suggesting that the bipedal ancestry of ornithischians did not constrain the development of quadrupedal locomotionviaa limited number of functional pathways. Functional anatomy appears to have had a greater effect on moment arms than phylogeny, and the differences identified between individual taxa and individual clades may relate to differences in locomotor performance required for living in different environments or for clade‐specific behaviours.