Captorhinus magnus, a new captorhinid (Amniota: Eureptilia) from the Lower Permian of Oklahoma, with new evidence on the homology of the astragalus
Captorhinus magnus, a new captorhinid (Amniota: Eureptilia) from the Lower Permian of Oklahoma, with new evidence on the homology of the astragalus
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DOI：
10.1139/e02-040
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发表时间：
2002-09-01
影响因子：
1.4
通讯作者：
Reisz, RR
中科院分区：
文献类型：
--
作者：
Kissel, RA;Dilkes, DW;Reisz, RR
本文报道了单齿喙科爬行动物Captorhinus magnus n.在俄克拉荷马州的理查兹支脉的早二叠世裂缝充填物中发现的Captorhinus sp.与Captorhinus aguti在体型、牙齿和股骨形态上不同。完全成熟C. magnus元素的大小是C的1.5 ~ 2.3倍。aguti和股骨近端关节面，这是凸的C。aguti，在整个个体发育中是凹的。C. magnus具有排成一行的卵形颊齿，表明卵形齿系不再被认为是C.阿古蒂。对captorhinid相互关系的系统发育分析表明，C。aguti和C. magnus形成一个分支，具有姐妹群的关系与Captorhinus laticeps。不完全骨化骨指C。magnus提供了明确的证据，即Captorhinus的黄芪是通过三个最初独立的骨化（胫骨，中间和近端中央）融合而形成的，而不是来自一个单一的骨化中心。在理查兹支线地区，C。magnus是最丰富的Captorhinus物种，产自采石场更深、地层更低的沉积物。然而，在最上层的，可能是较年轻的矿床中，这种情况是罕见的。阿古蒂是数量最多的理查兹刺头鲨科。
The new species of single tooth-rowed captorhinid reptile Captorhinus magnus n. sp. from the Lower Permian fissure fillings at Richards Spur, Oklahoma differs from Captorhinus aguti in body size and dental and femoral morphology. Linear measurements of fully mature C. magnus elements range in size from 1.5 to 2.3 times as great as those of C. aguti, and the proximal articular surface of the femur, which is convex in C. aguti, is concave throughout ontogeny. C. magnus possesses ogival cheek teeth aligned in a single row, indicating that ogival dentition can no longer be considered unique to C. aguti. A phylogenetic analysis of captorhinid interrelationships indicates that C. aguti and C. magnus form a clade that possesses a sister-group relationship with Captorhinus laticeps. Incompletely ossified astragali referred to C. magnus provide unequivocal evidence that the astragalus of Captorhinus formed through the fusion of three, originally separate ossifications, the tibiale, intermedium, and proximal centrale, rather than from a single ossification center. At the Richards Spur locality, C. magnus is the most abundant Captorhinus species produced from the deeper, stratigraphically lower sediments of the quarry. It is rare, however, in the uppermost, presumably younger deposits, where C. aguti represents the most numerous Richards Spur captorhinid.