ASTROCRATIS ACUTISPINA, NEW GENUS AND SPECIES, A NEW ASTEROID FROM THE LATE CRETACEOUS OF TEXAS

Astrocratis acutispina, n. gen. and sp., is described from the Upper C retaceous (Campanian) Pflugerville Formation of the upper Austin Group of Texas, USA. Although remarkably similar to Cenozoic Astropecten, A . acutispina differs from Astropecten in pairing of adambulacrals with inferomarginals and development of inferomarginal spines. Astrocratis provides further evidence for a Cretaceous origin of infaunal habits in post-Paleozoic asteroids. Ossicular alignment suggests a phylogenet ic lineage separate from that of Astropecten.