BIOL 1902 Lecture Notes - Lecture 12: Swim Bladder, Pharyngeal Slit, Lancelet
19 Apr 2016
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The diversity and history of life (part 2) Pentadactyly is a condition shared by all tetrapod"s. Pentadactyly is a four limbed 5 fingered species. Any tetrapod that does not have this has undergone a regression in their evolution. Under the tetrapods in the classes (amphibians and mammals are examples of classes) They (amphibians) are separated from amniotes because of their eggs, they do not have the embryos and their eggs are covered in some sort of slime thing. The distinctive features are that they fertilize externally, they have no scales and claws and they do not drink; they absorb water through the skin. Lobe fennec fish (most closely related fish to tetrapods, then ray finned fish and then the cartilaginous fish). Hagfish and the lampreys are the tetrapods with the slime glands; they secrete the slime onto potential predators and then the predators can"t close their mouth so they swim away because they can"t eat the lamprey.
