Data from: Phylogenetic analysis of the Archaeocidaridae and Palaeozoic Miocidaridae (Echinodermata, Echinoidea) and the origin of crown group echinoids

The archaeocidarids comprise the most derived stem group echinoids and
have long been regarded as closely related to the crown group echinoids.
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. Our analyses find 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 stratigraphic 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 n. sp. 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.