Ophiuroid diversity in the type area of the Maastrichtian Stage

Abstract

With the exception of holothurians, all Late Cretaceous (Campanian-Maastrichtian) and Early Palaeogene (Danian) echinoderms from the extended type area of the Maastrichtian Stage are currently being revised. In addition to a handful of taxa described previously in the literature, many new genera and species of brittle star and basket star (Ophiuroidea) have been recognised in recent years. In fact, the study area is one of the very few regions in the world that have yielded diverse ophiuroid faunas of latest Cretaceous age. Of note also is the fact that many of the new taxa are based on more or less complete specimens, i.e., discs preserving (portions of) arms, making generic assignment much more reliable. The various ophiuroid groups recognised are briefly discussed and selected specimens are illustrated in order to document the diversity. Formal descriptions will be published elsewhere. Ophiuroid taxa described by Berry (1938), as based on poorly preserved material from the Late Maastrichtian of the area, are briefly commented upon.