Feeding postures as indicators of mutable collagenous tissue in extinct echinoderms.

ABSTRACT: Echinoderms are a diverse phylum with a rich fossil record. The five extant classes of echinoderms are characterised by a pentameral (or pseudo-pentameral) symmetry, a water vascular system, a mesodermal skeleton of calcite stereom, and Mutable Collagenous Tissue (MCT), a unique type of connective tissue. Difficulties in tracing the geologic history of these traits complicates phylogenetic analyses of echinoderms. We present evidence herein of MCT in an extinct class of echinoderms, the Blastoidea. Blastoids have composite hair-like structures, brachioles, which formed a feeding filtration fan. Rare specimens from the Devonian of Germany demonstrate the presence of MCT by preserving brachioles as long rigid structures making a feeding fan with MCT in a rigid state. Specimens show brachiole

SUBMITTER: Waters JA 

PROVIDER: S-EPMC11568118 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature