College of Science and Engineering, Flinders University, Adelaide, 5042, Australia.
Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, Rimouski, G5L 3A1, Canada.
Nat Commun. 2024 Sep 12;15(1):7529. doi: 10.1038/s41467-024-51238-4.
The living coelacanth Latimeria (Sarcopterygii: Actinistia) is an iconic, so-called 'living fossil' within one of the most apparently morphologically conservative vertebrate groups. We describe a new, 3-D preserved coelacanth from the Late Devonian Gogo Formation in Western Australia. We assemble a comprehensive analysis of the group to assess the phylogeny, evolutionary rates, and morphological disparity of all coelacanths. We reveal a major shift in morphological disparity between Devonian and post-Devonian coelacanths. The newly described fossil fish fills a critical transitional stage in coelacanth disparity and evolution. Since the mid-Cretaceous, discrete character changes (representing major morphological innovations) have essentially ceased, while meristic and continuous characters have continued to evolve within coelacanths. Considering a range of putative environmental drivers, tectonic activity best explains variation in the rates of coelacanth evolution.
活腔棘鱼（肉鳍鱼总纲：肉鳍鱼亚纲）是形态上最为保守的脊椎动物类群之一中的标志性“活化石”。我们描述了来自西澳大利亚晚泥盆世戈戈组的一种新的、3D 保存完好的腔棘鱼。我们综合分析了这一类群，以评估所有腔棘鱼的系统发育、进化率和形态差异。我们揭示了泥盆纪和泥盆纪后腔棘鱼之间形态差异的重大转变。新描述的化石鱼填补了腔棘鱼差异和进化的关键过渡阶段。从中新世中期开始，离散特征变化（代表主要的形态创新）基本上已经停止，而在腔棘鱼中，可数特征和连续特征仍在继续进化。考虑到一系列假定的环境驱动因素，构造活动最能解释腔棘鱼进化率的变化。
