The Early Evolution of Echinoderms

From the Cambrian to the Ordovician, many animal phyla first appeared and diversified rapidly, and the phylum Echinodermata eventually became one of the major groups of marine animals that continues to thrive today. The ancestors of modern echinoderms—such as sea stars, sea urchins, and sea cucumbers—can largely be traced back to the early Paleozoic. During that time, echinoderms evolved at a remarkable pace. Within only a few tens of millions of years, they underwent extensive diversification in both phylogeny and morphology, ultimately giving rise to roughly twenty classes and dozens of orders. These included all the major body plans seen in living echinoderms, as well as many unusual forms that are now entirely extinct. Such rapid diversification indicates that the early evolutionary history of echinoderms was marked by extensive experimentation with different body structures.

Want to read more?

Subscribe to thesoundofevolution.com to keep reading this exclusive post.

Subscribe Now