Ambulacraria /ˌæmbjuːləˈkrɛəriə/, or Coelomopora /siːləˈmɒpərə/, is a clade of invertebrate phyla that includes echinoderms and hemichordates;[1] a member of this group is called an ambulacrarian.

Phylogenetic analysis suggests the echinoderms and hemichordates separated around 533 million years ago.

[2] The Ambulacraria are part of the deuterostomes, a clade that also includes the many Chordata, and the few extinct species belonging to the Vetulicolia.

[4]) Whether the Xenacoelomorpha clade is the sister group to the Ambulacraria remains a contentious issue, with some authors arguing that the former should be placed more basally among metazoans,[5][6][1] and other authors asserting that the best choices of phylogenetic methods support the position of Xenacoelomorpha as the sister group to Ambulacraria.

[12] The following cladogram is based on a simplification of Li et al. 2023,[14] with the possible placements of uncertain potential ambulacrarians shown with dashed lines and question marks: ?