BIO 200 Lecture Notes - Lecture 21: Osteichthyes, Gnathostomata, Lissamphibia
7 Nov 2016
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Document Summary
What makes a vertebrate: vertebrate traits, hagfish: sister taxa or the first vertebrates, lempreys. Fish: fish traits and classes, the evolution of jaws, teeth and the sharks, bony fish dominate the fish world. The invasion of land: lobed fish led the invasion of land, amphibian traits, terrestrial challenges led to ichthyostega, three modern classes of amphibians, the age of amphibians. Vertebrates all have: heads, endoskeletons supported by vertebrate, internal organs suspended in a coelem, circulatory system with a muscular heat. One of those internal organs is a muscular heart that powers and advanced circulatory system. Jawed fishes: anterior gill arches became jaws and greatly improved feeding efficiency. Shark species numbers have changed over time. Oceanic manta rays can reach at least 7 meters in width! Ray finned fish have parallel bony rays. Increasing oxygen intake and delivery to larger muscles required for walking. Modern amphibians do live in two worlds: aquatic, terrestrial. Frogs: long legs, smooth, moist skin.
