The archaeocidarids comprise the most derived stem group echinoids and have long been regarded as closely related to the crown group. The fossil record of echinoids in the Palaeozoic is, however, poor, so details surrounding the initial divergence of crown group echinoids are not well constrained. In order to better understand the phylogenetic relationships of the most derived stem group and most basal crown group echinoids, a phylogenetic analysis was undertaken of the Archaeocidaridae, including the genera Nortonechinus, Devonocidaris, Lepidocidaris, Polytaxicidaris and Archaeocidaris and the Palaeozoic miocidarid cidaroids from the genus Eotiaris. We found that Archaeocidaris appears to be paraphyletic with respect to crown group echinoids. Furthermore, we mapped character evolution along our phylogeny and found that the diversification of archaeocidarids and miocidarids may be linked to large‐scale macroecological changes taking place in the late Palaeozoic, including increasing predation pressure and echinoid encrustation by epibionts. We compared the stratigraphical distribution of archaeocidarid and miocidarid occurrences to our resulting phylogenies, and found that the fit of our cladograms to the stratigraphic record of archaeocidarid occurrences is worse than other echinoid groups, supporting the idea that the imbricate plated archaeocidarids have a poor fossil record. In the course of carrying out these analyses, we also felt it necessary to describe a new species of Archaeocidaris, Archaeocidaris ivanovi sp. nov. We also provide novel descriptions and interpretations for Devonocidaris primaevus, Archaeocidaris brownwoodensis, Archaeocidaris apheles and revise the synonymy of Archaeocidaris legrandensis and ?Eotiaris meurevillensis, which may be a crown group echinoid.

中文翻译：

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始尾科和古生代细科（Echinodermata，Echinoidea）的系统发育分析和冠群类chin虫的起源

始古龙蛛是类群中最衍生的类棘突类动物，长期以来一直被认为与冠类紧密相关。然而，古生代中的类神经质的化石记录很差，因此围绕冠状类神经质的初始发散的细节并没有受到很好的限制。为了更好地了解大多数派生的茎群和大多数基冠群类棘突类动物的系统发育关系，对古纲科进行了系统发育分析，包括北tone属，泥on纲，勒皮纲，多生纲和古纲纲以及古生的拟真纲Eotiaris。我们发现始祖鸟似乎对冠状类棘突类动物有寄生性。此外，我们绘制了沿系统发育特征的进化图谱，发现古生代和微古生代的多样化可能与古生代晚期发生的大规模宏观生态变化有关，包括捕食压力的升高和表皮虫对类固醇的结壳。我们比较了古龙骨和中古龙骨发生的地层分布与我们所形成的系统发育学，发现我们的克拉德图与古龙骨发生的地层记录的拟合度比其他棘突类动物差，支持了这样的观点，即盘状板状古龙骨的化石记录很差。在进行这些分析的过程中，我们还认为有必要描述一种新的Archaeocidaris，Archaeocidaris ivanovi SP。十一月 我们还提供了对原始肉食蟹（Devonocidaris primaevus），古细菌Archaeocidaris brownwoodensis，古细菌Archaeocidaris apheles的新颖描述和解释，并修改了Archaeocidaris legrandensis和？Eotiaris meurevillensis，可能是冠状类棘突类动物。