A 500-million-year-old fossil from Morocco, discovered by Natural History Museum scientists, is offering extraordinary new insights into one of evolution's most puzzling transformations: how ...

Echinoderms such as starfish are unusual for their five-fold body symmetry. Maps of gene-expression patterns show how this body plan was acquired, and that the genes specifying head structures do the ...

The extraxial axial theory is used to investigate homology of ambulacral and oral plating because it predicts terminal branching and terminal addition of plates in the axial skeleton, although ...

This is a preview. Log in through your library . Abstract How the radial body plan of echinoderms is related to the bilateral body plan of their deuterostome relatives, the hemichordates and the ...