superphylum of bilateral animals
Deuterostomes are a nephrozoan superphylum of bilaterian animals, a taxon above the level of phylum. It is not part of the usual system of classification.
Temporal range: late Ediacaran – Recent
|A sea cucumber|
|Phyla and clades|
They are bilateral animals, and are contrasted with the protostomes. Deuterostomes are distingued by their embryo: in deuterostomes, the first opening (the blastopore) becomes the anus, while in protostomes it becomes the mouth.
These are the living phyla of deuterostomes:
- Chordata (vertebrates and their kin)
- Echinodermata (starfishes, sea urchins, sea cucumbers, etc.)
- Hemichordata (acorn worms and possibly graptolites)
This is an extinct deuterostome clade: