A reassessment of the sea-star orders Valvatida and Spinulosida

Abstract

Affinities of a number of sea star families belonging to Valvatida and Spinulosida are problematic. Characters traditionally used in ordinal recognition are discussed; primary emphasis was placed on features readily subject to convergent evolution. In the past, skeletal morphology has received relatively little taxonomic emphasis but these data are used here to argue in favor of the transfer of the Ganeriidae, Asterinidae and Poraniidae from the Spinulosida to the Valvatida. Revised characterizations and familial content for the Valvatida and Spinulosida are suggested.