Scaling and functional morphology in strigiform hind limbs.
Scaling and functional morphology in strigiform hind limbs.
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DOI：
10.1038/srep44920
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发表时间：
2017-03-22
影响因子：
4.6
通讯作者：
Bright JA
中科院分区：
文献类型：
--
作者：
Madan MA;Rayfield EJ;Bright JA
鹰形目是一种专门由猫头鹰组成的猛禽目：鸮科（仓鸮）和鹰形目（真正的猫头鹰），它们通过一系列适应来帮助敏锐的掠食性生活方式，包括强壮的后肢元素，以增强握力。为了评估后肢形态的变化，我们分析了亚化石和现代物种的主要后肢元素的尺寸如何与体重成比例。将后肢单元长度、中轴宽度和健壮性指数（RI：中轴宽度与最大长度之比）与体重进行比较发现，股骨和胫跗骨宽度尺度为等距，而长度尺度为负异速，并且在胫跗骨中接近弹性相似。相反，跗跖骨宽度与体重呈强烈的正异速，而长度则呈强烈的负异速。此外，跗跖骨的RI与质量0.028呈异速缩放，而股骨（质量0.004）和胫跖骨（质量0.004）之间存在弱关系。我们的研究结果表明跗跖骨比胫跖骨和股骨起着更重要的功能作用。考虑到跗跖骨宽度与身体质量之间的比例关系，我们有可能通过分析跗跖骨来推断史前猫头鹰的身体质量，这是猫头鹰化石记录中经常保存的一种元素。
Strigiformes are an order of raptorial birds consisting exclusively of owls: the Tytonidae (barn owls) and the Strigidae (true owls), united by a suite of adaptations aiding a keen predatory lifestyle, including robust hind limb elements modified for grip strength. To assess variation in hind limb morphology, we analysed how the dimensions of the major hind limb elements in subfossil and modern species scaled with body mass. Comparing hind limb element length, midshaft width, and robusticity index (RI: ratio of midshaft width to maximum length) to body mass revealed that femoral and tibiotarsal width scale with isometry, whilst length scales with negative allometry, and close to elastic similarity in the tibiotarsus. In contrast, tarsometatarsus width shows strong positive allometry with body mass, whilst length shows strong negative allometry. Furthermore, the tarsometatarsi RI scales allometrically to mass0.028, whilst a weak relationship exists in femora (mass0.004) and tibiotarsi (mass0.004). Our results suggest that tarsometatarsi play a more substantial functional role than tibiotarsi and femora. Given the scaling relationship between tarsometatarsal width and robusticity to body mass, it may be possible to infer the body mass of prehistoric owls by analysing tarsometatarsi, an element that is frequently preserved in the fossil record of owls.