Earth Sciences 2266F/G Lecture Notes - Lecture 1: Gill Slit, Dorsal Nerve Cord, Endostyle
26 Jul 2016
School
Department
Course
Professor
Document Summary
Vertebrates is a subgroup of the phylum chordata. They have a notochord, which will become spinal cord. Plesiomorphic characters are also known as primitive characters characters you can find in ancient vertebrate ancestors. Apomorphic characters new or derived characters characters only present in this particular group and cannot find it in ancestors. When you compare vertebrates to invertebrates, verts have bilateral symmetry (like in worms, but not in jellyfish/coral); allows them to move faster (radial not good for moving) Coelomate: each cavity surrounded by membrane for organ development; some worms don"t have a coelum (corals and sponges don"t have organs so no body cavity) Gill slits: evolved from invertebrates where we can make a link between verts and inverts. In apomorphic characters, these are only in vertebrates and not in invertebrates at all. Endostyle: mucus as defense purposes but originally was for trapping food.
