Phylogeny and biogeography of some Cretaceous spatangoid echinoids with special emphasis on taxa from the Western Interior Seaway

• DOI: 10.1017/jpa.2020.102
• Publication Date: 2020-12-15T09:48:57Z
• Authors: Steven Byrum; Bruce S. Lieberman
• Keywords: Vicariance; Cenomanian; Aptian

Abstract Members of the echinoid order Spatangoida, a highly diverse and abundant marine invertebrate clade, were important denizens Cretaceous Western Interior Seaway (WIS), an epicontinental seaway that divided North America in two during interval greenhouse conditions between roughly 100 65 million years ago. A phylogenetic analysis spatangoids was conducted using character matrix 32 characters from 21 species. Species occur WIS considered comprehensively, species other regions such as South America, Europe, Africa also incorporated into analysis. Phylogenetic patterns retrieved are largely congruent with preexisting family-level classifications; however, within several genera, especially Hemiaster Heteraster , need to be reassigned so classification better reflects phylogeny. The genera Washitaster closely related, Mecaster Palhemiaster Proraster ; Pliotoxaster Macraster Micraster Diplodetus . Biogeographic phylogeny, episodes vicariance range expansion identified. These possibly related some various major sea-level rise fall Cretaceous. In particular, Valangian–mid-Aptian regressions may have caused while early spatangoid late Aptian–early Cenomanian. Further, by mid-Cenomanian–Maastrichtian driven diversification Last, transgressions Cenomanian seem spurred prominent expansions