BIOL-3030 Lecture Notes - Lecture 11: Amniote, New Idea, Paleozoic
Document Summary
Sarcopterygians are osteichthyans that have a robust, skinny skeleton in appendages (fins/limbs) Tetrapodomorpha are united together by sharing a choanae (internal nostril) They have a choana but generally retain fish like traits/features. Fore fin is closer to tetrapod limb than hindlimb. Has dactylus limbs limbs with digits. As evolution and time went on the animals began to look more like what we know as tetrapods. Their limbs used to be all fused together with large bones. As evolution continued the shapes of toes and fingers became more distinct and less connected. Hand and foot polydactylous (7 hind and 8 fore digits) Are able to be seen in fossil records that have been found. The first tetrapods were aquatic - tetrapod features are not necessarily for living on land (possible for walking in shallow water or living sometimes on land/sometimes in water) Polydactyly in fossil taxa - they contain 5 digits not ancestral for tetrapods.
