Macroevolutionary and morphofunctional patterns in theropod skulls: A morphometric approach
Macroevolutionary and morphofunctional patterns in theropod skulls: A morphometric approach
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DOI：
10.4202/app.2011.0145
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发表时间：
2013-03-01
影响因子：
1.8
通讯作者：
Rauhut, Oliver W. M.
中科院分区：
文献类型：
--
作者：
Foth, Christian;Rauhut, Oliver W. M.
兽脚类恐龙是中生代陆生脊椎动物中最重要的类群之一，具有高度的分类和生态多样性。我们调查了非鸟类兽脚亚目和一些基础鸟类的颅骨多样性，使用几何形态测量学来深入了解头骨的进化修改。兽脚类头骨主要在吻部的形状和眶后区的长度（主成分[PC] 1）上变化，在眼眶形状、眶后区的深度和颌关节的位置（PC 2和PC 3）上进一步变化。这些结果表明，兽脚亚目恐龙的头骨形状与生殖发育和饮食偏好密切相关。非肉食性类群的头骨形状与肉食性类群有显著差异，这表明饮食偏好影响头骨形状。此外，我们发现前三个PC轴和功能代理（平均最大应力和颅骨强度指标）之间存在显着相关性。有趣的是，基栖鸟类在形态空间中占据了很大的面积，这表明它们具有很高的颅骨多样性，因此也具有很高的生态多样性。然而，我们只能包括少数的基底鸟类物种，因为它们的头骨很脆弱，很少有好的头骨重建。考虑到热河生物群中已知的基底鸟类多样性，本研究结果可能低估了基底鸟类的形态多样性。
Theropod dinosaurs are one of the most remarkable lineages of terrestrial vertebrates in the Mesozoic, showing high taxonomic and ecological diversity. We investigate the cranial diversity of non-avian theropods and some basal birds, using geometric morphometrics to obtain insights into the evolutionary modifications of the skull. Theropod skulls mostly vary in the shape of the snout and length of the postorbital region (principal component [PC] 1), with further variation in orbit shape, depth of the postorbital region, and position of the jaw joint (PC 2 and PC 3). These results indicate that the cranial shape of theropods is closely correlated with phylogeny and dietary preference. Skull shapes of non-carnivorous taxa differ significantly from carnivorous taxa, suggesting that dietary preference affects skull shape. Furthermore, we found a significant correlation between the first three PC axes and functional proxies (average maximum stress and an indicator of skull strength). Interestingly, basal birds occupy a large area within the morphospace, indicating a high cranial, and thus also ecological, diversity. However, we could include only a small number of basal avialan species, because their skulls are fragile and there are few good skull reconstructions. Taking the known diversity of basal birds from the Jehol biota into account, the present result might even underestimate the morphological diversity of basal avialans.