EEB384H1 Lecture Notes - Lecture 5: Scleroglossa, Acrodont, Rhynchocephalia
16 Feb 2016
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Document Summary
Molecular phylogenetics and fossils dates to middle triassic origin. Growth occurs between the end of the bone (epiphysis) and the shaft (diaphysis) shed skin all at once (lizards referred to as snakes because lizards are a paraphyletic group) --snakes shed all in one piece. In epidermal layer there is inner generating layer and outer generating layer , the stratum corneum makes the upper layer in both and it is unique because it has beta keratin protein . Amphibians do not have beta keratin but reptiles do in the upper half of each of the generating layers in the epidermis . Eyes look milky before skin is shed and the skin looks dull then body starts to peel back. Ability to shed the tail and regenerate it. Ancestor trait but some have lost this ability. Rhyncociphalians can shed tail and widely in squamata. After tail is gone they regenerate a cartilage rod at the cleavage plane.
