Lecture 9.2

Lecture 9.2 - Lecture 9.2 Wednesday, March 05, 2008 3:07 PM...

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Cartilaginous endoskeleton - Streamlined - A degree of cephalization - First bone appearance Ordovician (480 mya) First internal bony skeletons Jaws Silurian (430 mya) Ostracoderm, jawless fish - Burgess Shale (544-515 mya) Chordate Fossil Records + Innovations Stiff Strong Highly cellular Metabolically active CaPO 4 - Calcium Phosphate CaCO 3 - Calcium Carbonate Bone Pharyngeal arches Pharyngeal arches Jaws hyoid (?) Innovation of jaws opened up feeding niches ~25,000 species Bony skeleton - Homologous for arms and legs Paired fins (2) - Protrusible jaws - Actinopterygians - ray finned fish C M PCT Chondricichthyes No Bone - Vertebrae - BOne - Actinorterygians (Fins) (Ray) Sarcopterygians Dominant deuterostome forms (actinopterygians) But also see the first appearance of tetrapods Devonian (Age of Fishes) 350 mya Transitions to Land Devonian - Support body weight Walk instead of swim Locomotor system - Air instead of water Keep respiratory structures
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This note was uploaded on 04/20/2008 for the course BIOL 94 taught by Professor Gaut/summers during the Winter '08 term at UC Irvine.

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