ZOO 2090 Lecture Notes - Lecture 9: Terrestrial Locomotion, Seymouriamorpha, Sarcopterygii

• School: University of Guelph
• Department: Zoology
• Course: ZOO 2090
• Professor: Fred Laberge

Document Summary

Discuss the different hypotheses about the origin of tetrapods. Describe the anatomical trends from lobe-finned fishes to early tetrapods. Explain how modifications to the appendicular skeleton enabled locomotion on land. Describe early modes of locomotion in tetrapods. Crossoterygii which is a sister group of tetrapods with lungfish as an outgroup. Left lungfishes and coelacanths as a sister group of tetrapods. Right osteolepiformes as sister group of tetrapods. Crossopterygii has no meaning here included more recent discoveries, but they maintained crossopterygii. However, molecular data suggests that lungfishes are more closely related to tetrapods than the coelacanth (if you take only the living form) tetropodomorpha tetrapods + some advanced sarcopterygians. What is a tetrapod? vertebrate that possess a chiridium (muscular limb with well- defined joints and digits) some authors use the term stegocephalians, which comprises the tetrapods (amphibians + amniotes) and other digit-bearing vertebrates (i. e. , the early tetrapods )