View source for Protostome

{{Automatic taxobox
| fossil_range={{Fossil range|570|0|Ediacaran - Recent}}
| name=Protostomes
| image = <imagemap>
File:Protostomia.jpg|220px
rect 0 0 660 660 [[Arthropod]]
rect 0 660 660 1320 [[Mollusca]]
rect 0 1320 660 1980 [[Annelid]]
rect 660 0 1320 660 [[Nematode]]
rect 660 660 1320 1320 [[Flatworm]]
rect 660 1320 1320 1980 [[Rotifer]]
</imagemap>
| display_parents=4
| taxon=Protostomia
| authority=[[Karl Grobben|Grobben]], 1908 
| subdivision_ranks=Superphyla
| subdivision=
*[[Ecdysozoa]]
*[[Spiralia]]
}}

'''Protostomes''' are a [[nephrozoa]]n [[taxon]] of [[animal]]s above the level of [[phylum]]. It is not part of the normal system of [[classification]]. 

They are a subtaxon of the [[Bilateria]], and are contrasted with the [[deuterostome]]s. Protosomes are distingued by their [[embryo]]: in deuterostomes, the first opening (the blastopore) becomes the [[anus]], while in protostomes it becomes the mouth.

[[DNA]] [[sequence analysis]] suggests that protostome animals can be divided into three major groups:
*[[Ecdysozoa]], e.g. [[arthropod]]s,  [[nematode]]s
*[[Platyzoa]], e.g. [[platyhelminthes]], [[rotifer]]s
*[[Lophotrochozoa]], e.g. [[mollusc]]s, [[annelid]]s
as well as a number of minor taxa, like the [[Chaetognatha]].

[[Category:Invertebrates]]
[[Category:Groups of phyla]]