Sizing the Jurassic theropod dinosaur Allosaurus:: Assessing growth strategy and evolution of ontogenetic scaling of limbs
Sizing the Jurassic theropod dinosaur Allosaurus:: Assessing growth strategy and evolution of ontogenetic scaling of limbs
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DOI：
10.1002/jmor.10406
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发表时间：
2006-03-01
影响因子：
1.5
通讯作者：
Lamm, ET
中科院分区：
文献类型：
--
作者：
Bybee, PJ;Lee, AH;Lamm, ET
异特龙是中生代最常见的兽脚亚目恐龙之一。我们提出了一个组织学分析，以评估其生长策略和个体发生肢体骨鳞。根据纤维板层骨的肱骨、尺骨、股骨和胫骨部分的个体发生序列，我们估计样本中最大个体的年龄在13-19岁之间。生长曲线重建显示，最大生长发生在15岁，此时体重增加148 kg/年。根据异特龙更大的骨头，我们估计它的年龄上限在22-28岁之间，这与其他大型兽脚亚目恐龙的初步数据相似。模型1和模型11的回归分析都表明，相对于股骨的长度，肱骨、尺骨和胫骨的长度增长比等距预测的要慢。异特龙的肢体鳞片模式与其他大型兽脚亚目恐龙如暴龙相似。系统发育优化表明，大型兽脚亚目动物通过相对于股骨的纵向生长减少而独立地进化出肱骨、尺骨和胫骨的长度减少。
Allosaurus is one of the most common Mesozoic theropod dinosaurs. We present a histological analysis to assess its growth strategy and ontogenetic limb bone scaling. Based on an ontogenetic series of humeral, ulnar, femoral, and tibial sections of fibrolamellar bone, we estimate the ages of the largest individuals in the sample to be between 13-19 years. Growth curve reconstruction suggests that maximum growth occurred at 15 years, when body mass increased 148 kg/year. Based on larger bones of Allosaurus, we estimate an upper age limit of between 22-28 years of age, which is similar to preliminary data for other large theropods. Both Model I and Model 11 regression analyses suggest that relative to the length of the femur, the lengths of the humerus, ulna, and tibia increase in length more slowly than isometry predicts. That pattern of limb scaling in Allosaurus is similar to those in other large theropods such as the tyrannosaurids. Phylogenetic optimization suggests that large theropods independently evolved reduced humeral, ulnar, and tibial lengths by a phyletic reduction in longitudinal growth relative to the femur.