BIOL 1200 Lecture Notes - Lecture 11: Agnatha, Cambrian Explosion, Ecdysozoa
Document Summary
Most bilaterians possess a body cavity (coelom), a fluid- or air-filled space between the digestive tract and the outer body wall. Body cavity may cushion suspended organ: diversification of animals. Zoologists recognize about 3 dozen animal phyla - combine molecular data from multiple sources to determine relationships amongst them: bilaterian radiation 1: diverse invertebrates. 3 major clades: lophotrochozoa, ecdysozoa, deutrostomia: overview of invertebrate diversity. Account for 95% of animal species, morphologically diverse. Sunlight restricted the location of plants(many areas in the ocean that had prevented plants from growing due sunlight not being able to reach) Bulk of animals on planet are ecdysozoa. Lophotrochozoa are the most morphologically diverse (in terms of body sizes and body plans: ecdysozoa. Grow in spurts (they molt) -> during period they are extremely vulnerable to predators since they can not move. Body of an arthropod is covered by cuticle (exoskeleton; protein and chitin)
