Synonymy of Astropecten nitidus Verrill, 1915 with Astropecten cingulatus Sladen, 1883 and Astropecten comptus Verrill, 1915 with Astropecten articulatus (Say, 1825)

Abstract Verrill described Astropecten comptus and Astropecten nitidus 100 years ago. The species have been accepted and have been reported off the east coast of North America and South America, the Caribbean, and the Gulf of Mexico. The validity of the species has never been questioned. Because we had difficulty distinguishing A. comptus from A. articulatus and A. nitidus from A. cingulatus, we examined basic morphological diagnostic characteristics in astropectens of the neotype of A. articulatus, the holotype of A. cingulatus, the paralectotype of A. comptus, the holotype of A. nitidus, the holotype of A. nitidus forcipatus, and many specimens that had been identified as A. cingulatus, A. nitidus, A. articulatus, A. comptus, and other Astropecten species of the West Atlantic Region. We conclude that A. comptus is a synonym of A. articulatus and A. nitidus is a synonym of A. cingulatus. This has implications for current concepts of zoogeography and biodiversity in the region and for the phylogeny of astropectinids.