A computational analysis of limb and body dimensions in Tyrannosaurus rex with implications for locomotion, ontogeny, and growth.
A computational analysis of limb and body dimensions in Tyrannosaurus rex with implications for locomotion, ontogeny, and growth.
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DOI：
10.1371/journal.pone.0026037
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Makovicky PJ
中科院分区：
文献类型：
--
作者：
Hutchinson JR;Bates KT;Molnar J;Allen V;Makovicky PJ
大型兽脚亚目恐龙雷克斯暴龙在不到20年的时间里从不到10公斤的幼仔成长到6000公斤的成年恐龙，经历了巨大的变化。这些变化引发了一些有趣的问题，包括形态学的转变、最高生长速率、肢体肌肉大小的缩放以及身体的质量中心，这些都可能影响霸王龙运动的个体发生变化。在这里，我们使用四个大型，保存完好的化石标本以及一个假定的幼年个体的三维扫描计算机模型来解决这些问题。此外，我们量化了估计的体重，质量中心和部分尺寸的变化，以表征我们重建中的不准确性。这些不准确不仅包括主观性，还包括博物馆骨骼的不完整保存和不一致的关节。尽管这些问题造成了不确定性，但我们得出结论，成年霸王龙的体重在6000-8000公斤之间，已知最大的标本（“苏”）可能在9500公斤左右。我们的研究结果表明，在霸王龙个体发育过程中，躯干变长变重，而四肢则相应地变短变轻。我们对峰值增长率的估计大约是以前的两倍，但总体上支持以前的方法，尽管使用比例模型和低估体重的方程会造成偏差。我们初步推断，在霸王龙个体发育过程中，包括大尾股长尾肌在内的后肢伸肌群的相对大小可能随着质量中心的颅向移位而减小。这种个体发生的改变会加重最大运动能力的相对或绝对下降。不管怎样，霸王龙的臀部和大腿肌肉可能比任何现存的动物都要大。总的来说，四肢的“反重力”肌肉可能和鼠鸟一样大，甚至比它们的肌肉还要大，而鼠鸟的四肢是所有现存动物中肌肉最发达的。
The large theropod dinosaur Tyrannosaurus rex underwent remarkable changes during its growth from <10 kg hatchlings to >6000 kg adults in <20 years. These changes raise fascinating questions about the morphological transformations involved, peak growth rates, and scaling of limb muscle sizes as well as the body's centre of mass that could have influenced ontogenetic changes of locomotion in T. rex. Here we address these questions using three-dimensionally scanned computer models of four large, well-preserved fossil specimens as well as a putative juvenile individual. Furthermore we quantify the variations of estimated body mass, centre of mass and segment dimensions, to characterize inaccuracies in our reconstructions. These inaccuracies include not only subjectivity but also incomplete preservation and inconsistent articulations of museum skeletons. Although those problems cause ambiguity, we conclude that adult T. rex had body masses around 6000–8000 kg, with the largest known specimen (“Sue”) perhaps ∼9500 kg. Our results show that during T. rex ontogeny, the torso became longer and heavier whereas the limbs became proportionately shorter and lighter. Our estimates of peak growth rates are about twice as rapid as previous ones but generally support previous methods, despite biases caused by the usage of scale models and equations that underestimate body masses. We tentatively infer that the hindlimb extensor muscles masses, including the large tail muscle M. caudofemoralis longus, may have decreased in their relative size as the centre of mass shifted craniodorsally during T. rex ontogeny. Such ontogenetic changes would have worsened any relative or absolute decline of maximal locomotor performance. Regardless, T. rex probably had hip and thigh muscles relatively larger than any extant animal's. Overall, the limb “antigravity” muscles may have been as large as or even larger than those of ratite birds, which themselves have the most muscular limbs of any living animal.
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影响因子：
56.9
作者：
BIEWENER, AA
通讯作者：
BIEWENER, AA
影响因子：
2.4
作者：
Allen, Vivian;Elsey, Ruth M.;Hutchinson, John R.
通讯作者：
Hutchinson, John R.
DOI：
10.1111/j.1096-3642.1985.tb00871.x
发表时间：
1985-01-01
影响因子：
2.8
作者：
ALEXANDER, RM
通讯作者：
ALEXANDER, RM
使用激光成像和3D计算机建模估算恐龙的质量特性。
影响因子：
3.7
作者：
Bates KT;Manning PL;Hodgetts D;Sellers WI
通讯作者：
Sellers WI
影响因子：
2
作者：
ALEXANDER, RM;VERNON, A
通讯作者：
VERNON, A