Grzimek's Animal Life Encyclopedia: Vol. 2 Protostomes by Michael Hutchins
English | Nov 21, 2003 | ISBN: 0787657786 | 569 Pages | PDF | 47.7 MB
English | Nov 21, 2003 | ISBN: 0787657786 | 569 Pages | PDF | 47.7 MB
The term Protostomia (from the Greek “proto,” meaning first, and “stoma,” meaning mouth) was coined by the biologist Karl Grobben in 1908. It distinguishes a group of invertebrate animals based upon the fate of the blastopore (the first opening of the early digestive tract) during embryonic development. Animals in which the blastopore becomes the mouth are called protostomes; those in which the mouth develops after the anus are called deuterostomes (from the Greek “deutero,” meaning second, and “stoma,” meaning mouth).