Primitive echinoderms and the origin of the modern body plan
A solute, a pre-radiate echinoderm
Evolution of the pentaradiate body plan
The fossil record provides a direct record of the body plan organisation of echinoderms before they had firmly adopted a pentaradiate pattern.
By studying these extinct pre-radiate groups we can build up a picture of how such a singular body plan arose from a bilaterian ancestor.
Origins of living echinoderm classes
Work is also going on to trace the origins of the major echinoderm classes still in existence, particularly:
- holothurians
- echinoids