Morphometric comparison of the Hesperornithiformes and modern diving birds
Morphometric comparison of the Hesperornithiformes and modern diving birds
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DOI：
10.1016/j.palaeo.2017.12.010
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发表时间：
2019-01-01
影响因子：
3
通讯作者：
Chiappe, Luis M.
中科院分区：
文献类型：
--
作者：
Bell, Alyssa;Wu, Yun-Hsin;Chiappe, Luis M.
白垩纪的黄昏鸟形目是一种已经灭绝的水鸟，长期以来被认为是用脚推动潜水的。这种特殊化在今天的一些现代鸟类家族（潜鸟，，鸬鹚和一些鸭子）中可以看到，它们已经融合了潜水的生活方式。在历史上，黄鸟形目通常被比作现代潜鸟和。然而，这些比较是基于骨骼形态的定性观察，从未使用形态测量数据进行过测试。研究这种功能趋同的形态细节提供了一个机会，以更好地了解灭绝的Hesperornithiformes的生活方式，特别是在适应脚推进潜水和生态龛这些鸟类可能occupied.This study presented a morphometric analysis of hesperornithiformes and modern foot-propelled diving birds.测量收集了8个属的现代鸟类和6个属的hesperornithiforms的跗跖骨，胫跗骨和股骨。为了探索数据中的变化，对许多不同的测量组合（例如，跗跖骨和胫跗骨，或胫跗骨和股骨）进行主成分分析（PCA）。研究不同亚群数据的主要原因是为了增加化石标本之间的分类包容性，其中缺失的数据是研究的最大障碍。这项研究结果表明，hesperornithiforms很少与潜鸟或grebes共享morphospace，但更经常与鸬鹚和潜水鸭共享morphospace。因此，潜鸟和可能不是最适合作为黄昏鸟形目的类似物。结合详细的形态学工作，使用这些分析，可能会增强我们对鸟类和其他生物之间复杂生态策略和生态位划分的进化的理解。
The Cretaceous Hesperornithiformes are an extinct group of aquatic birds long recognized to have practiced foot-propelled diving. This specialization is seen today in a number of modern avian families (loons, grebes, cormorants, and some ducks) that have convergently derived a diving lifestyle. Historically, hesperornithiforms have usually been compared to modern loons and grebes as analogues. However, these comparisons are based on qualitative observations of skeletal morphology and have never been tested using morphometric data. Studying the morphological details underlying this functional convergence provides an opportunity to better understand the lifestyle of the extinct Hesperornithiformes, particularly in regard to adaptations for foot-propelled diving and ecological niches these birds may have occupied.This study presents a morphometric analysis of the hindlimb of hesperornithiforms and modem foot-propelled diving birds. Measurements were collected from the tarsometatarsus, tibiotarsus, and femur of eight genera of modern birds and six genera of hesperornithiforms. In order to explore variation within the data, a number of different combinations of measurements (for example, tarsometatarsus and tibiotarsus, or tibiotarsus and femur) were subjected to principal components analyses (PCA). The primary reason for investigating the data in different subsets was to increase taxonomic inclusion among the fossil specimens, where missing data was the largest impediment to the study.Results of this study show that hesperornithiforms rarely shared morphospace with loons or grebes, but more often did share morphospace with cormorants and diving ducks. Therefore, loons and grebes may not serve as the most appropriate analogue for the Hesperornithiformes. Use of these sorts of analyses, in conjunction with detailed morphological work, may enhance our understanding of the evolution of complex ecological strategies and niche partitioning among birds and other organisms.