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Lecture 6 ANIMAL EVOLUTION: THE VERTEBRATES. Features of vertebrates. Bones (vertebrae) Have fins Gills Jaws . Early craniates. Craniates are animals with cranium E.g. fishes, amphibians, reptiles, birds and mammals. Jawless fishes & ostracoderms evolved. Then jawed craniates evolved.
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Features of vertebrates • Bones (vertebrae) • Have fins • Gills • Jaws
Early craniates • Craniates are animals with cranium • E.g. fishes, amphibians, reptiles, birds and mammals. • Jawless fishes & ostracoderms evolved. • Then jawed craniates evolved. • Jaws – hinged, bony feeding structures. • Hagfishes & lampreys – the only surviving jawless fishes. • Placoderms - earliest jawed fishes.