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Unformatted text preview: - Modification of gill arches (bars of cartilage; support gills).
What Did It Do?
enabled ﬁsh to bite! Allowed capture and processing of wide array of food. - Spectacular radiation of jawed fishes followed. Transitional fossils have been found that show the evolution of an early, but completely nonfunctional form of the jaw is
NOT par of the evidence scientists have collected for the idea that the jaw evolved from gill arches. The Tetrapod Limb
- First land vertebrates (amphibians) arose from group of
bony fish with sturdy fins and lungs: “lobe-finned fishes”
- Related to modern-day lungfish and coelocanths.
* Fins (supported by bone) limbs
- All tetrapod limbs are homologous.
What Did It Do? Allowed efﬁcient movement on land. - Basic limb evolved into diverse forms for running,
swimming, digging, flying etc. Feathers and Flight
- Flight evolved independently in 3
pterosaurs, bats, and birds.
- Birds evolved from lineage of feathered,
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