BIOL 1002 Chapter : Ch 24 Animal Diversity II
Document Summary
Chapter 24 animal diversity ii - the chordata. The last group of animals features four new characteristics: nerve chord lies above the digestive tract on the upper- dorsal- portion of body, unlike other animals (fig 23-11) In others, only present in early embryonic development. Tails: posterior extension that continues past the anus. 5-week old fetus: during embryonic development we lose 3 of the 4 chordate characteristics, we keep nerve chord, notochord changes to our spine, and we had gill slits and tail. The organisms with these (and other features) are the: 3 clades: tunicates, lancelets, craniates (almost all are vertebrates) Tunicates (aka sea squirts and salps) figure 24-3: adult tunicates are sessile and lose their larval stage tails and notochords. Lancelets retain all four chordate features as adults (fig. They filter water through their gill slits while they are half-buried in the sandy sea bottom. Invertebrate like tunicate: get name because lance-shape-long, other features of the chordates:
