PREDATION BY THE ORDOVICIAN ASTEROID PROMOPALAEASTER ON A PELECYPOD

An Ordovician Promopalaeaster (Echinodermata: Asteroidea) wrapped abou t a Cuneamya? (Mollusca: Pelecypoda) in the extraoral feeding posture characteristic of Jurassic to modern members of the Asteriidae documen ts an early origin for this behavioral complex. Modern asteriids are c onvergent on Promopalaeaster, there is no direct phylogenetic linkage between the two. This fossil occurrence, combined with the success of modern Asteriidae, demonstrates that biological evolution and geologic al change need not outmode complex life habits. The fossil supports th e notion of asteroids as Paleozoic-type predators, and its existence s uggests that asteroids were not significant contributors to changing f aunal structures in shelf seas during the Phanerozoic.