| The palaeobiology of echinoderms occurring in the Meerssen and Geulhem members is discussed and changes in diversity across the K/T boundary are documented. Using literature data on the ecology of extant faunas, the various echinoderm groups are considered. Naturally, such data can only be applied with due caution to fossil forms, whose skeletal morphology is often incompletely known. This holds especially true for asteroids, ophiuroids, and crinoids, which, upon death, rapidly disintegrate into jumbles of dissociated ossicles. Bioturbation, scavenging, and current winnowing all contribute to blurring the picture still further. However, data on extant forms do allow a preliminary subdivision of fossil species into various ecological groups, which are... |
