ZOO 2090 Lecture Notes - Lecture 7: Gastralium, Articular Processes, Humerus

• School: University of Guelph
• Department: Zoology
• Course: ZOO 2090
• Professor: Jinzhong Fu

Document Summary

Transition of early tetrapods from living in water to living on land is major event in vertebrate evolution. Emergent vertebrates experience extraordinary challenges to their ability of: movement, respiration. The earliest tetrapods (late devonian) were aquatic, and many changes that were later useful for terrestrial life were evolved primarily in water. Sarcopterygians: relationships within that group is highly controversial, transition to tetrapods is most important evolutionary change, competing hypotheses. The (cid:862)classic(cid:863) (cid:448)ie(cid:449) (cid:894)ro(cid:373)er, 19(cid:1010)(cid:1010)(cid:895: rhipidistia, actinistia + tetrapoda together form crossopterygii, with lungfishes at the base. Left(cid:198)lungfishes and coelacanths as a sister group of tetrapods (forey et al. , 1991: right(cid:198)osteolepiformes as a sister group of tetrapods (panchen and smithson, crossopterygii has no meaning here. Zhu and schultze (2001) included more recent discoveries, but they maintained. Tetrapodmorpha(cid:198)tetrapods + some advanced sarcopterygians (i. e. eusthenopteron, pandericthys, tiktaalik : however, molecular data suggests that lungfishes are more closely related to, a possible scenario (clack, 2002) tetrapods than to coelacanths.