Deuterostome
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| Deuterostomia Fossil range: late Ediacaran – Recent |
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| A Sea cucumber | |||||||||
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Deuterostomes are a superphylum of animals, a taxon above the level of phylum. It is not part of the usual system of classification.
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.
[change] Classification
There are four living phyla of deuterostomes:
- Phylum Chordata (vertebrates and their kin)
- Phylum Echinodermata (starfishes, sea urchins, sea cucumbers, etc.)
- Phylum Hemichordata (acorn worms and possibly graptolites)
- Phylum Xenoturbellida (2 species of worm-like animals)
