A new asteroid (Echinodermata) faunule from the Early Cretaceous (Barremian) of Morocco

Abstract

An asteroid (Echinodermata) faunule of four taxa representing three surviving families and a probable fourth is described from the Barremian (Early Cretaceous) of Morocco, northwest Africa. The four together suggest limited morphologic evolution since the Cretaceous but biogeographic and depth patterns have changed. Marocaster coronatus n. gen. n. sp. (Valvatida, Goniasteridae) combines apparent derived features of the dorsal disk and superomarginal shape with more stemward expressions of the abactinal ossicles. Betelgeusia orientalis n. sp. is a fourth Mesozoic occurrence of the Radiasteridae (Paxillosida), the new species similar to earlier occurrences from the Middle Jurassic of India, the Early Cretaceous of Texas, and the Late Cretaceous of Europe. Reported modern occurrences of the family are few, widely scattered, and limited to deeper water; the extinct species together testify to a once-broader familial distribution. Dipsacaster africanus n. sp., a member of the Astropectinidae (Paxillosida), is remarkably similar to extant congeners. Dipsacaster today is widely distributed in the Pacific Ocean but occurrences in the Atlantic are few. Because of preservation, a single small specimen of the Zoroasteridae? (Forcipulatida) cannot be identified with certainty. Extant zoroasterids are deep-water in distribution, although shallow-water Eocene representatives are known.