“Echinodermata”

“Echinodermata”

“Echinodermata”

Phylogeny of the echinoderms
A cladogram in the sand depicts the evolutionary relationships between the five classes of echinoderms: asteroidea (sea stars), ophiuroidia (brittle stars), echinoidea (sea urchins and sand dollars), holothuroidea (sea cucumbers), and crinoidea (sea lillies and feathers).