A new species of Lasalichthys (Actinopterygii, Redfieldiiformes) from the Upper Triassic Dockum Group of Howard County, Texas, with revisions to the genera Lasalichthys and Synorichthys
A new species of Lasalichthys (Actinopterygii, Redfieldiiformes) from the Upper Triassic Dockum Group of Howard County, Texas, with revisions to the genera Lasalichthys and Synorichthys
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DOI：
10.1080/02724634.2018.1513009
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发表时间：
2018-09
影响因子：
1.4
通讯作者：
Sarah Z. Gibson
中科院分区：
文献类型：
--
作者：
Sarah Z. Gibson
本文记述了红原形鱼类一新种--奥茨卡尔河Lasalichthys otischalkensis，sp. nov.，是基于新的，三维保存标本从上三叠统的多库姆组霍华德县，得克萨斯州西部。Lasalichthys otischalkensis的诊断是通过头骨中发现的独特特征的组合，包括上颌骨的形状，前盖骨和相关颧骨的形状，吻部骨骼的模式和关节，以及真皮头骨中感觉线管道的模式。这个新物种的标本在头骨的感觉线管道中显示出从未在任何其他红田形动物中观察到的新模式。通过对上三叠统钦勒组和多克姆群的Lasalichthys和Synorichthys标本的分析比较，发现这两个类群仅在种的水平上有区别，而Synorichthys与Lasalichthys在形态特征上有明显区别。Lasalichthys otischalkensis是北美最古老的红田形分类群之一。
ABSTRACT A new species of redfieldiiform fishes, Lasalichthys otischalkensis, sp. nov., is described based on new, three-dimensionally preserved specimens from the Upper Triassic Dockum Group of Howard County, western Texas. Lasalichthys otischalkensis is diagnosed by a combination of unique traits found in the skull, including shape of maxilla, shape of preoperculum and associated cheek bones, pattern and articulation of bones in the snout, and patterns of sensory line canals in the dermal skull bones. Specimens of this new species display novel patterns in the sensory line canals of the skull that have never been observed in any other redfieldiiform. Examination and comparison of specimens of Lasalichthys and Synorichthys from the Upper Triassic Chinle Formation and Dockum Group indicates that these taxa are only distinguishable at the species level, and Synorichthys is placed into synonymy with Lasalichthys, based on comparison of diagnostic morphological characters. Lasalichthys otischalkensis represents one of the oldest redfieldiiform taxa in North America.