Laboratório de Paleontologia de Vertebrados e Comportamento Animal, Universidade Federal do ABC, São Bernardo do Campo, Brazil.
Department of Natural History Sciences, Hokkaido University, Sapporo, Hokkaido, Japan.
PeerJ. 2023 Feb 9;11:e14829. doi: 10.7717/peerj.14829. eCollection 2023.
Tapejarids are edentulous pterosaurs particularly abundant in the Chinese Jiufotang Formation, counting with over 10 described specimens and dozens of undescribed ones. A total of seven nominal tapejarid species (within two genera) have been proposed, though it is disputed how many of those are valid instead of sexual or ontogenetic morphs of fewer, or a single, species. However, detailed revisions of the matter are still lacking. In the present work, we provide a specimen-level survey of anatomical variation in previously described Jiufotang tapejarid specimens, as well as of six new ones. We present qualitative and morphometric comparisons, aiming to provide a basis for a taxonomic reappraisal of the complex. Our results lead us to interpret two Jiufotang tapejarid species as valid: and (gen. et comb. nov.). Our primary taxonomic decisions did not rely around cranial crest features, which have typically been regarded as diagnostic for most of these proposed species albeit ever-growing evidence that these structures are highly variable in pterosaurs, due to ontogeny and sexual dimorphism. However, a reassessment of premaxillary crest variation in the complex reveals that while much of the observed variation (crest presence and size) can easily be attributed to intraspecific (ontogenetic and sexual) variation, some of it (crest shape) does seem to represent interspecific variation indeed. A phylogenetic analysis including the species regarded as valid was also performed.
翼手龙是无齿的翼龙，在中国九佛堂组中特别丰富，已有超过 10 个描述的标本和几十个未描述的标本。总共提出了七种翼手龙属（两个属）的命名物种，尽管对于这些物种中有多少是有效的，而不是更少的性或个体发育形态，或者是单一的物种，存在争议。然而，详细的修订仍然缺乏。在本工作中，我们对以前描述的九佛堂翼手龙标本以及六个新标本进行了详细的解剖变异研究。我们进行了定性和形态测量比较，旨在为该类群的分类再评价提供基础。我们的结果表明，两种九佛堂翼手龙被解释为有效种：（gen. et comb. nov.）和 （gen. et comb. nov.）。我们的主要分类决策不依赖于颅冠特征，尽管越来越多的证据表明，这些结构在翼龙中由于个体发育和性二态性而高度可变，但这些特征通常被认为是大多数这些提议的物种的特征。然而，对 复杂种的前颌嵴变异的重新评估表明，虽然观察到的大部分变异（嵴的存在和大小）很容易归因于种内（个体发育和性）变异，但其中一些（嵴的形状）确实似乎代表种间变异。还进行了包括被认为有效的物种的系统发育分析。
