Bayerische Staatssammlung für Paläontologie und Geologie, München, Germany.
PLoS One. 2012;7(7):e39370. doi: 10.1371/journal.pone.0039370. Epub 2012 Jul 11.
The Ginglymodi is one of the most common, though poorly understood groups of neopterygians, which includes gars, macrosemiiforms, and "semionotiforms." In particular, the phylogenetic relationships between the widely distributed "semionotiforms," and between them and other ginglymodians have been enigmatic. Here, the phylogenetic relationships between eight of the 11 "semionotiform" genera, five genera of living and fossil gars and three macrosemiid genera, are analysed through cladistic analysis, based on 90 morphological characters and 37 taxa, including 7 out-group taxa. The results of the analysis show that the Ginglymodi includes two main lineages: Lepisosteiformes and †Semionotiformes. The genera †Pliodetes, †Araripelepidotes, †Lepidotes, †Scheenstia, and †Isanichthys are lepisosteiforms, and not semionotiforms, as previously thought, and these taxa extend the stratigraphic range of the lineage leading to gars back up to the Early Jurassic. A monophyletic †Lepidotes is restricted to the Early Jurassic species, whereas the strongly tritoral species previously referred to †Lepidotes are referred to †Scheenstia. Other species previously referred to †Lepidotes represent other genera or new taxa. The macrosemiids are well nested within semionotiforms, together with †Semionotidae, here restricted to †Semionotus, and a new family including †Callipurbeckia n. gen. minor (previously referred to †Lepidotes), †Macrosemimimus, †Tlayuamichin, †Paralepidotus, and †Semiolepis. Due to the numerous taxonomic changes needed according to the phylogenetic analysis, this article also includes formal taxonomic definitions and diagnoses for all generic and higher taxa, which are new or modified. The study of Mesozoic ginglymodians led to confirm Patterson's observation that these fishes show morphological affinities with both halecomorphs and teleosts. Therefore, the compilation of large data sets including the Mesozoic ginglymodians and the re-evaluation of several hypotheses of homology are essential to test the hypotheses of the Halecostomi vs. the Holostei, which is one of the major topics in the evolution of Mesozoic vertebrates and the origin of modern fish faunas.
栉齿鳚目是新鳍鱼亚纲中最常见但了解甚少的类群之一，包括𬶐科、 macrosemiiforms 和 "半鳍目"。特别是，广泛分布的"半鳍目"之间以及它们与其他栉齿鳚目的系统发育关系一直是个谜。在这里，基于 90 个形态特征和 37 个分类单元（包括 7 个外群分类单元），通过分支分析研究了 11 个 "半鳍目"属中的 8 个属、5 个活化石𬶐科和 3 个 macrosemiid 属之间的系统发育关系。分析结果表明，栉齿鳚目包括两个主要的谱系：𬶐形目和 †半鳍目。以前认为†Pliodetes、†Araripelepidotes、†Lepidotes、†Scheenstia 和 †Isanichthys 属是𬶐形目，而不是半鳍目，这些分类单元将导致𬶐科的谱系的地层范围追溯到早侏罗世。单系的†Lepidotes 仅限于早侏罗世的物种，而以前被归入†Lepidotes 的强烈热带物种则被归入†Scheenstia。其他以前被归入†Lepidotes 的物种代表其他属或新分类单元。macrosemiids 与半鳍目一起很好地嵌套在半鳍目内，包括 †Semionotidae，这里限于 †Semionotus，以及一个新的科，包括 †Callipurbeckia n. gen. minor（以前归入 †Lepidotes）、†Macrosemimimus、†Tlayuamichin、†Paralepidotus 和 †Semiolepis。由于根据系统发育分析需要进行大量的分类群更改，本文还包括所有属和更高分类单元的正式分类定义和诊断，这些定义和诊断是新的或修改的。中生代栉齿鳚目的研究证实了 Patterson 的观察结果，即这些鱼类与 halcomorphs 和 teleosts 具有形态相似性。因此，编译包括中生代栉齿鳚目在内的大型数据集和重新评估几个同源假说对于测试 Halecostomi 与 Holostei 的假说至关重要，这是中生代脊椎动物进化和现代鱼类区系起源的主要课题之一。
