Earth Sciences 2266F/G Lecture Notes - Lecture 12: Lissamphibia, Eusthenopteron, Tiktaalik
26 Jul 2016
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Document Summary
Basal tetrapods is the term used for amphibians. If you look at living amphibians, including frog, toad, salamander, they lost their limbs in evolution looking like an earthworm, but they still have vertebrae; they just went through degenerative evolution. None of the modern amphibians are in the direct lineage to evolving to reptiles (only ancestors) Modern amphibians and reptiles come from a common ancestor near the triassic-permian boundary not direct lineage. In one group, reptiliomorph, look like half amphibian half reptile, and these are the beginning of reptiles, will eventually lay eggs (amniota) But we are going to look at the first part, where fish evolves into amphibians. Good fossils in early cretaceous, so ancestors must be earlier. Salamander with long tail, and long, broad head. Transition was much earlier from fish to amphibian. Good fossils found in devonian, mostly in greenland. During the transition, these are the problems we have to solve from going from water to land.
