Deuterostomes (from Greek: lit. 'mouth second') are bilaterian animals of the superphylum Deuterostomia (/ˌdjuːtərəˈstoʊmi.ə/), typically characterized...

of triploblastic, enterocoelomate, and bilaterally symmetrical marine deuterostome animals, generally considered the sister group of the echinoderms. They...

lineages, but are not part of the formal definition: All chordates are deuterostomes. This means that, during embryonic development, the anus forms before...

the arthropods, molluscs, flatworms, annelids and nematodes; and the deuterostomes, which include the echinoderms, hemichordates and chordates, the latter...

become its digestive tube (the archenteron). In the sister-clade, the deuterostomes (lit. 'second-mouth'), the original dent becomes the anus while the...

happened at least twice, following different paths in protostomes and deuterostomes. This accompanied or facilitated other important evolutionary developments:...

stem- and crown-group arthropods, stem-group vertebrates, and early deuterostomes (a group which as a whole includes the vertebrates, other invertebrate...

ago in the beginning of the Cambrian period. Initially proposed as a deuterostome, which would make it the oldest known species of this superphylum, it...

shown by the foot pads. In 2017, a description of a new species of basal deuterostome called Saccorhytus was published. This animal appears to have seta in...

Pharyngeal slits are filter-feeding organs found among deuterostomes. Pharyngeal slits are repeated openings that appear along the pharynx caudal to the...