Evolution, Development and Anatomy of Echinoderms (EchinodermHexamery)

Basic data for this project

Description

Echinoderms are the only animal group showing a fundamental pentameric body plan. They also are deuterostomians and thus closely related to vertebrates. Their strikingly different body thus poses a long-standing puzzle. The central theme of this project is to explain the pentamery, in the light of development and evolution. The basal hypothesis is that this pentamery evolved as an adaptation to sessile life. According to this hypothesis, the bilaterally symmetric settles on the sea floor, and develops asymmetrically to lift the mouth upward for feeding. In this process, one part of the original hexamery is lost to attachment structures, leaving a mouth surrounded by a pentameric (hexamery-minus-one) feeding structure. The project aims at the development of extant as well as early forms, as well as the evolution of skelettal elements. An extended goal is to solve the early, Cambrian radiation of pentameric and asymmetric body forms.