Homology of posterior interray plates in crinoids: a review and new perspectives from phylogenetics, the fossil record and development

Despite their importance for understanding phylogeny, character evolution and classification, well‐constrained homology relationships for posterior plating in crinoids have only recently been attempted. Here, we re‐evaluate posterior plate homologies in all major crinoid lineages using development,...

Full description

Saved in:
Bibliographic Details
Published in:Palaeontology 2020-07, Vol.63 (4), p.525-545
Main Authors: Ausich, William I., Wright, David F., Cole, Selina R., Sevastopulo, George D., Smith, Andrew
Format: Article
Language:English
Subjects:
crinoids
development
Fossils
Homology
Marine invertebrates
Ontogeny
Palaeozoic
Paleozoic
Phylogenetics
Phylogeny
Terminology
Topology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Despite their importance for understanding phylogeny, character evolution and classification, well‐constrained homology relationships for posterior plating in crinoids have only recently been attempted. Here, we re‐evaluate posterior plate homologies in all major crinoid lineages using development, fossil ontogenies and phylogenetic evidence. Based on these lines of evidence, we change terminology for some posterior plates to correct misnomers and make recommendations for updated terminology of others to better reflect homology. Among pentacrinoids (disparids, hybocrinids, eucladids, flexibles and articulates) the relative position of posterior interray plates, not their topology, reflects homology. From proximal to distal, pentacrinoid posterior plates are the radianal, anal X and right sac plate, regardless of the total number of plates in the adult calyx. Camerate posterior plating contrasts with pentacrinoids, but insufficient data are available to resolve homology relationships between these two clades. More examples of early post‐larval ontogeny are needed in camerates and other Palaeozoic crinoids.
ISSN:0031-0239
1475-4983
DOI:10.1111/pala.12475