Diversity of Mesozoic semionotiform fishes and the origin of gars (Lepisosteidae)
Diversity of Mesozoic semionotiform fishes and the origin of gars (Lepisosteidae)
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DOI：
10.1007/s00114-010-0722-7
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发表时间：
2010-12-01
影响因子：
--
通讯作者：
Cavin, Lionel
中科院分区：
文献类型：
--
作者：
Cavin, Lionel
Gars（Lepisosteidae）是辐鳍鱼类，与其他放线鱼谱系的关系存在争议。当考虑化石类群时，雀鳝被归为中生代巨半目和半目中的“半目”，但该目内的内部关系仍然难以捉摸。在这里，在系统发育分析中使用一组保存完好的灭绝半单类类群重新研究了鳝的进化史。结果表明，雀鳝谱系起源于晚侏罗世-白垩纪半鳉鱼的一个分支。与雀鳝关系最近的亲戚是食草性和食腐质的淡水鱼。全世界早白垩世早期和晚白垩世早期大陆沉积物中半鲤鱼遗骸的出现可能反映了该类群的重要辐射，与当今鲤鱼类的多样化相当。其他晚三叠世至早白垩世的半单类类群聚集在一个具有弱支撑内部节点的进化枝中，这表明有必要更好地了解这些鱼类的骨学。
Gars (Lepisosteidae) are ray-finned fishes with controversial relationships to other actinopterygian lineages. When fossil taxa are considered, gars are grouped with Mesozoic macrosemiids and 'semionotids' in the Semionotiformes, but the intra-relationships within this order are still elusive. Here, the evolutionary history of gars is reinvestigated using a set of well-preserved extinct semionotiform taxa in a phylogenetic analysis. Results indicate that the gar lineage roots in a clade of Late Jurassic-Cretaceous semionotiform fishes. The closest relatives to gars were plant-eating and detritivorous freshwater fishes. The occurrence of semionotiform remains in Early and early Late Cretaceous continental deposits worldwide possibly reflects an important radiation of this group, comparable to the present-day diversification of cypriniforms. Other Late Triassic to Early Cretaceous semionotiform taxa are gathered in a single clade with weakly supported internal nodes, pointing out the necessity to better understand the osteology of these fishes.