A redescription of Carrolla craddocki (Lepospondyli: Brachystelechidae) based on high‐resolution CT, and the impacts of miniaturization and fossoriality on morphology
A redescription of Carrolla craddocki (Lepospondyli: Brachystelechidae) based on high‐resolution CT, and the impacts of miniaturization and fossoriality on morphology
复制标题
基于高分辨率 CT 的 Carrolla craddocki（Lepospondyli：Brachystelechidae）的重新描述，以及小型化和化石性对形态的影响
DOI：
10.1002/jmor.10946
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发表时间：
2011
影响因子：
1.5
通讯作者：
Jason S. Anderson
中科院分区：
文献类型：
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作者：
Hillary C. Maddin;Jennifer C. Olori;Jason S. Anderson
最近的一些形态学分析对Lissampibia（青蛙，蝾螈和Caecilians）的单系性提出了质疑。在这些分析中，发现短柱蜥类（brachystelechid）“微型龙”是无尾目的姐妹类群。为了验证这一假设，对短柱蜥蜴Carrolla craddocki的正模标本进行了高分辨率X射线计算机断层扫描，以深入了解支持短柱蜥蜴和无尾目之间潜在关系的形态学性质。这项分析使我们能够对内部解剖结构进行详细描述，例如脑囊和耳囊内模（第一次为lepospondyl），以及有关头骨结构的新信息。我们的研究结果表明，短中柱蜥蜴的颅骨形态受到小型化（扩大的感觉器官，下颌关节的前部放置，以及骨化减少和骨化过度的组合）和穴居习惯（具有宽，倾斜的枕骨表面的共同骨化的脑壳，颅骨顶部骨之间的重叠关节，以及骨化良好的前脑壳）的强烈影响。与体型缩小和洞穴挖掘无关的短中柱虫的特征是菱形头骨和可能的有蒂齿系。我们提供了一个修订的诊断Carrolla，并确定可能的新字符内的解剖结构的脑壳和内耳。目前将无尾目和“微龙”联系在一起的几个特征都与小型化或穴居有关，这表明未来的努力应该继续关注解剖学的细节，这些细节受这些影响最小，以有助于解决无尾目的起源问题。J. Morphol. 2011.© 2011 Wiley利斯公司
Some recent morphological analyses have brought into question the monophyly of Lissamphibia (frogs, salamanders, and caecilians). In these analyses, brachystelechid “microsaurs” are found to be sister group to caecilians. To test this hypothesis, the holotype specimen of the brachystelechid Carrolla craddocki was submitted to high‐resolution X‐ray computed tomography to gain insight into the nature of the morphology supporting the potential relationship between brachystelechids and caecilians. This analysis enabled us to conduct a detailed description of the internal anatomy such as the braincase and otic capsule endocast (the first of its kind for a lepospondyl), and new information regarding the architecture of the skull. Our results suggest brachystelechid cranial morphology is strongly influenced by miniaturization (enlarged sensory organs, anterior placement of the jaw articulation, and combination of both reduced‐ and hyper‐ossifications) and burrowing habits (co‐ossified braincase with broad, sloping occipital surface, overlapping joints between skull roof bones, and well‐ossified anterior braincase). Characteristics of brachystelechids that appear unrelated to size‐reduction and burrowing are the diamond‐shaped skull and possible pedicellate dentition. We provide a revised diagnosis for Carrolla and identify possible new characters within the anatomy of the braincase and inner ear. Several characters currently uniting caecilians and “microsaurs” are among those associated with either miniaturization or burrowing, demonstrating that future efforts should continue to focus on fine details of anatomy minimally affected by these influences to contribute to the resolution of the question of the origin of caecilians. J. Morphol. 2011. © 2011 Wiley‐Liss, Inc.
DOI：
--
发表时间：
2000-08
期刊：
The Journal of experimental biology
影响因子：
--
作者：
M. Smotherman;P. Narins
通讯作者：
M. Smotherman;P. Narins