Differentiation and Growth of Bone Ornamentation in Vertebrates: A Comparative Histological Study Among the Crocodylomorpha
Differentiation and Growth of Bone Ornamentation in Vertebrates: A Comparative Histological Study Among the Crocodylomorpha
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DOI：
10.1002/jmor.20351
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发表时间：
2015-04-01
影响因子：
1.5
通讯作者：
Laurin, M.
中科院分区：
文献类型：
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作者：
de Buffrenil, V.;Clarac, F.;Laurin, M.
骨突起，即真皮骨表面上的中空（凹坑和凹槽）或突出（脊）的重复浮雕，是脊椎动物中常见的特征，尽管研究和理解很少。最典型的例子之一是Crurotarsi，这是一个由鳄鱼和他们最亲密的盟友形成的分类群，通常在头骨顶部和骨皮上显示出深裂。然而，负责这种性格的分化和发展的个体发育过程仍然存在争议。本研究旨在解决几个crurotarsan类群的组织学和显微解剖学证据的问题。现存和灭绝的鳄鱼类动物的观察和实验数据表明，骨再生最初是通过一个复杂的骨重建过程产生的，后来在体细胞生长期间（在鳄鱼类动物中是不确定的）维持，该过程包括浅表骨皮质的局部吸收，然后是部分重建。因此，鳄鱼皮骨的表面浮雕通过凹坑扩大、漂移、拉伸、收缩或完全填充而永久改变。山脊也以相应的方式重塑。这些过程允许在生长过程中将单一的装饰图案适应骨骼的整体尺寸。一个简约优化的基础上，这项研究的结果，但也整合了非crocodyliform crurotarsans和一些非crurotarsan类群的骨组织学的数据，表明上述的特殊机制，创造和维持骨的骨结合是一个一般特征的Crurotarsi，是相当不同的，从以前的作者归因于其他脊椎动物。(C)2014 Wiley Periodicals，Inc.
Bone ornamentation, that is, hollow (pits and grooves) or protruding (ridges) repetitive reliefs on the surface of dermal bones, is a frequent, though poorly studied and understood, feature in vertebrates. One of the most typical examples of this characteristic is given by the Crurotarsi, a taxon formed by the crocodilians and their closest allies, which generally display deep ornamentation on skull roof and osteoderms. However, the ontogenetic process responsible for the differentiation and development of this character remains controversial. This study was conducted to settle the question on histological and microanatomical evidence in several crurotarsan taxa. Observational and experimental data in extant and extinct crocodyliforms show that bone ornamentation is initially created, and later maintained during somatic growth (that is indefinite in crocodilians), by a complex process of bone remodeling comprising local resorption of superficial bone cortices, followed by partial reconstruction. The superficial reliefs of crocodilian dermal bones are thus permanently modified through pit enlargement, drift, stretching, shrinking, or complete filling. Ridges are also remodeled in corresponding ways. These processes allow accommodation of unitary ornamental motifs to the overall dimensions of the bones during growth. A parsimony optimization based on the results of this study, but integrating also published data on bone histology in non-crocodyliform crurotarsans and some non-crurotarsan taxa, suggests that the peculiar mechanism described above for creating and maintaining bone ornamentation is a general feature of the Crurotarsi and is quite distinct from that attributed by previous authors to other vertebrates. (C) 2014 Wiley Periodicals, Inc.