BIO153H5 Chapter 34: Chapter 34 Notes.docx
Document Summary
The deuterostomes include the largest bodied and some of the most morphologically complex of all animals. When humpback whale, sea urchin, or human just beginning to grow, the gut starts developing from posterior to anterior with the anus forming first and the mouth second. A coelom develops from out pocketings of mesoderm. The vertebrates, comprise the hagfish, lampreys, sharks, bony fishes, amphibians, mammals, and reptiles (including birds) The echinoderms named for spikes observed in many species. Echinodermata is a large and diverse phylum that is exclusively marine. They are the 2nd most successful lineage of deuterostomes next to vertebrates. All deuterostomes are considered bilaterians, because they evolved from an ancestor that was bilaterally symmetric. Remarkable event early in the evolution of echinoderms: the origin of five sided radial symmetry, called pentaradial symmetry, in adults. If adult echinoderms are capable of movement, they tend to move equally well in all directions.
