deuterostome

[ doo-ter-uh-stohm, dyoo- ]

noun

1. Embryology. a mouth that develops separately from the blastopore.
2. Taxonomy. any member of the phyla (Chordata, Hemichordata, Echinodermata, Chaetognatha) in which the anus appears first, developing at or near the blastopore, cleavage is radial and indeterminate, and the mesoderm and coelom form from outgrowths of the primitive gut.

deuterostome

/ do̅o̅′tə-rō-stōm′ /

1. Any of a major group of animals defined by its embryonic development, in which the first opening in the embryo becomes the anus. At this stage in their development, the later specialized function of any given embryonic cell has not yet been determined. Deuterostomes are one of the two groups of animals that have true body cavities (coeloms), and are believed to share a common ancestor. They include the echinoderms, chaetognaths, hemichordates, and chordates.
2. Compare protostome

Word History and Origins

Origin of deuterostome¹

First recorded in 1945–50; deutero- + -stome

Example Sentences

Gill slits are commonly found in deuterostomes, so their presence seemingly nailed the critter’s spot on the animal family tree.

From Science News