Beyond Endocasts: Using Predicted Brain-Structure Volumes of Extinct Birds to Assess Neuroanatomical and Behavioral Inferences
Beyond Endocasts: Using Predicted Brain-Structure Volumes of Extinct Birds to Assess Neuroanatomical and Behavioral Inferences
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DOI：
10.3390/d12010034
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发表时间：
2020-01-01
期刊：
影响因子：
2.4
通讯作者：
Witmer, Lawrence M.
中科院分区：
文献类型：
--
作者：
Early, Catherine M.;Ridgely, Ryan C.;Witmer, Lawrence M.
大脑的形状影响鸟类的头骨形态，这两个特征都受到系统发育和功能限制的影响。对鸟类颅骨和神经解剖学进化的研究得到了灭绝鸟类数据的加强，但完整的3D保存的脊椎动物大脑并没有从化石记录中得知，因此大脑内模通常作为替代品。最近对现存鸟类的研究表明，伍尔斯特和视叶忠实地代表了它们潜在的大脑结构的大小，这两者都参与了鸟类的视觉通路。七种灭绝鸟类的内模是从它们头骨的microCT扫描中产生的，以添加到现存鸟类的内模样本中，并测量了它们的Wulsts和视叶的表面积。基于贝叶斯推理的系统发育预测方法被用来计算这些灭绝鸟类的大脑结构的体积的基础上，其覆盖的内膜结构的表面积。这项分析导致了这些灭绝的鸟类和所有7种灭绝的鸟类的视顶盖体积的hyperpalanum卷。对各种大脑尺寸指标的脑结构体积和内膜结构表面积进行了系统发育ANCOVA（phyANCOVA）回归，以确定任何灭绝鸟类中这些结构的相对尺寸是否与现存鸟类的相对尺寸显着不同。样本。系统发育ANCOVA表明，没有灭绝的鸟类研究的相对hyperpallial体积显着不同的现存样本，也没有任何他们的视顶盖相对肥大。粗壮恐鸟的视顶盖相对于大脑的大小比我们样本中现存的任何鸟类都要小。这项研究提供了一个分析框架，以测试其他灭绝鸟类的潜在功能行为能力的基础上，他们的endocast的假设。
The shape of the brain influences skull morphology in birds, and both traits are driven by phylogenetic and functional constraints. Studies on avian cranial and neuroanatomical evolution are strengthened by data on extinct birds, but complete, 3D-preserved vertebrate brains are not known from the fossil record, so brain endocasts often serve as proxies. Recent work on extant birds shows that the Wulst and optic lobe faithfully represent the size of their underlying brain structures, both of which are involved in avian visual pathways. The endocasts of seven extinct birds were generated from microCT scans of their skulls to add to an existing sample of endocasts of extant birds, and the surface areas of their Wulsts and optic lobes were measured. A phylogenetic prediction method based on Bayesian inference was used to calculate the volumes of the brain structures of these extinct birds based on the surface areas of their overlying endocast structures. This analysis resulted in hyperpallium volumes of five of these extinct birds and optic tectum volumes of all seven extinct birds. Phylogenetic ANCOVA (phyANCOVA) were performed on regressions of the brain-structure volumes and endocast structure surface areas on various brain size metrics to determine if the relative sizes of these structures in any extinct birds were significantly different from those of the extant birds in the sample. Phylogenetic ANCOVA indicated that no extinct birds studied had relative hyperpallial volumes that were significantly different from the extant sample, nor were any of their optic tecta relatively hypertrophied. The optic tectum of Dinornis robustus was significantly smaller relative to brain size than any of the extant birds in our sample. This study provides an analytical framework for testing the hypotheses of potential functional behavioral capabilities of other extinct birds based on their endocasts.