Chordata
Aubrey Irwin
Agnatha
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Oldest Class of Vertebrates*
Jaw-less animals
Cylinder, eel-shaped body
The notochord persists in the adult
The skeleton is composed of cartilage
Example: Lampreys
Chondrichthyes
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Cartilaginous fish
Skeletons made of cartilage
Internal jaws are present
Paired appendages
Three semicircular canals
Example: Sharks
Osteichthyes
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Bony fish
Skeletons made of bone
Operculum (a flap on each side of the head that covers the gills). The movements of
these flaps allow the fish to breathe without moving.
Most bony fish are carnivorous, few are herbivores that feed on algae and aquatic plants,
and some are filter feeders
Example: Ray-finned fish
Amphibia
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1st vertebrates adapted to live both on land and water
Reproduce in water or moist land
Glandular skin that lacks the keratinized scales
Most have complex life cycles
Surrounded by several gelatinous layers
Example: Salamanders
Reptilia
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Able to retain moisture
Live on land
Produce eggs that do not have to develop in water
Improved Skelenton
Shelled eggs
Scaly skin
Examples: Turtles
Aves
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Birds
Presence of feathers
Appendages modified as wings
High metabolic rate
Bones that are lightened by numerous air
spaces
Mammalia
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Have hair/fur
Mammary glands
Three middle ear bones
Warm Blooded
Lungs are present
Example: Tigers
Three Groups
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Vertebrates
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Tunicates
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Lancelets
Overview/Characteristics
• All have tails, hollow nerve cord, notochord,
and pharyngeal slits at some point of life or
development.
Vertebrates
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Large
Active
Well developed brains in hard skull
Segmented backbone
Example: Humans
Tunicates
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Urochordates
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Free swimming/sessile
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Example: Sea squirts
Lancelets
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Cephalochordates
Small
Eel-like
Found in shallow tropical oceans
Example:Lancelet