Ambulacraria

Ambulacraria or Coelomopora is a clade of invertebrate phyla which includes echinoderms and hemichordates; a member of this group is called an ambulacrarian. Phylogenetic analysis suggest the echinoderms and hemichordates separated around 533 million years ago. The Ambulacraria are part of the deuterostomes, a larger clade that also includes the Chordata, Vetulicolia and Saccorhytus.

The two living clades with representative organisms are:
 * Echinodermata (sea stars, sea urchins, brittle stars, sea cucumbers, feather stars, sea lilies, etc.)
 * Hemichordata (acorn worms, Pterobranchia, and possibly graptolites)

The group Xenoturbellida (two species of worm-like animals) has previously been considered to be in this clade, but is now considered to be placed more basally among Metazoans.

Fossil taxa that may lie on the stem lineage:
 * Superphylum Ambulacraria
 * unranked clade Cambroernida
 * † unranked clade = Eldoniida
 * † Stellostomites Caron, Conway Morris & Shu, 2010
 * † Velumbrella?
 * † Herpetogaster Caron, Conway Morris & Shu, 2010 - with one species: † Herpetogaster collinsi Caron, Conway Morris & Shu, 2010
 * † Rotadisciidae
 * † Seputus? Murray, J & MacGabhann