Phylum

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Phylum Chordata
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• notochord rod of
• cartilage at some time
• or back bone
• endoskeleton
• gill slits - at sometime
• dorsal hollow nerve cord
• post anal tail

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• somites blocks of mesoderm
• form vertebra and muscle

• prominent cephalization
• (nervous tissue at
• anterior ( brain )

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Gill slits
Vertebrate embryo
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gills
gills
Salamander tadpole
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No gills as adult
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Gill slits
somites
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Endoskeleton - cartilage or
calcified bone Protects brain and nerve cord
as the vertebral column Muscles are attached
to bone Marrow makes blood cells
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pelvic girdle
pectoral girdle
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A vertebral column replaces the notochord in
most vertebrates
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Vertebrate embryo development gives
evidence of evolutionary
ancestry
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Closed circulatory system with 2-4
chambered heart efficiently pumps blood
throughout the body
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• Fish have a 2 chambered heart
• Heart Gills
• Body
• a low pressure system
• slow flow

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From body
to gills
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• most highly evolved
• very complex behaviors
• some warm and fuzzy
• supporting rod or backbone
• dorsal hollow nerve cord
• closed circulatory system
• gills slits at some time
• prominent cephalization