Erickson Gregory M, Makovicky Peter J, Inouye Brian D, Zhou Chang-Fu, Gao Ke-Qin
Department of Biological Science, Florida State University, Tallahassee, Florida, USA.
Anat Rec (Hoboken). 2009 Sep;292(9):1514-21. doi: 10.1002/ar.20992.
Very little is known about nonavian dinosaur population biology. Multi-individual sampling and longevity estimation using growth line counts can be used to construct life tables-the foundation for population analyses in ecology. Here we have determined the size and age distribution for a sample consisting of 80 individuals of the small ornithischian, Psittacosaurus lujiatunensis from the early Cretaceous Yixian Formation of China. Their ages ranged from less than a year to eleven years and the distribution was strongly right-skewed. This is consistent with taphonomic interpretations that these animals derive from a catastrophic death assemblage. The static life table analysis revealed the same general pattern of survivorship as tyrannosaurs including increased attrition before the attainment of full adult size. This may reflect increased physiological demands and/or predation exposure associated with reproduction. Collectively these findings suggest that most nonavian dinosaurs may have had a similar life history strategy.
对于非鸟类恐龙的种群生物学，我们知之甚少。利用生长线计数进行多个体采样和寿命估计，可用于构建生命表——生态学中种群分析的基础。在此，我们确定了一个样本的大小和年龄分布，该样本由来自中国早白垩世义县组的80个小角龙类鹦鹉嘴龙个体组成。它们的年龄从不到一岁到十一岁不等，分布严重右偏。这与埋藏学解释一致，即这些动物来自灾难性死亡组合。静态生命表分析揭示了与暴龙相同的总体生存模式，包括在达到完全成年体型之前死亡率增加。这可能反映了与繁殖相关的生理需求增加和/或被捕食风险增加。这些发现共同表明，大多数非鸟类恐龙可能具有相似的生活史策略。
