Chordate Characteristics

UrochordatesTunicates & Sea Squirts

Cephalochordates

Lancelets (Amphioxus)

- True vertebrae

- Gills

http://upload.wikimedia.org/wikipedia/commons/e/e5/Lamprey_illustration_side.png

• Bone in their skeleton • An operculum covering the gill openings

• A swimbladder or lungs• True scales• Paired fins• Ammonia excretion

http://www.ucmp.berkeley.edu/vertebrates/sarco/lungfish1.jpg

Amphibia

• Tetrapod• Ectothermic• 3-chambered heart (Double circulation)• Smooth skin, lacks scales (Desiccation if

dry)• Cutaneous respiration• Lungs• Excretes urea

Tadpoles Frogs

Herbivorous Carnivorous

Aquatic Aquatic & Terrestrial

Single loop circulation Double loop circulation

Gills Lungs

http://libarynth.org/_detail/imagescleaned_washed_fiji_tree_frog_eggs_close-up.jpg?id=when_nature_inflates

Reptile Characteristics

• Ectothermic

• Dry skin covered in scales

• Most have 2 pairs of short legs & clawed feet

• Oviparous reproduction

• Internal fertilization – to avoid desiccation of gametes

Eggs amniotic

Lungs to breathe

3 or 4 chambered heart

No metamorphosis

Hibernate & aestivate

Excretory Waste

• The excretory waste of the reptiles is uric acid

Endothermic

Feathers = modified scales

Wings

Hollow bones

4 chambered heart

Amniotic egg

Parental care

Crop & gizzard

Air sacs & lungs

Counter-current circulation

Uric Acid excretion

Mammals• Endothermic

• Mammary glands

• Fur

• 4 chambered heart

• Diaphragm