Ch. 34

CharacteristicsNotochordDorsal, hollow nerve cordMuscular post-anal tailGill slits

Gills

Simple ChordatesUrochordata – tunicatesCephalochordata – lancelets

Challenges FacedChasing foodGrabbing food when closeGetting oxygen from environmentGetting oxygen through bodyPreventing dehydrationMaintaining body temperatureKeeping embryos from drying out

FishAgnathans

FishEvolution of jaws

Fish - ChondrichthyesLateral line

Fish - OsteichthyesOperculumSwim bladder

Class Amphibia

Class AmphibiaGills as

juvenileLousy lungsMoist skin

Class AmphibiaImproved circulation

Class Reptilia

Class ReptiliaParaphyletic

Class ReptiliaDry skinAmniotic eggsInternal fertilization

Class ReptiliaBranching in lungs

Class ReptiliaPartial septum in heart

Class Aves

Class AvesLightweight, hollow bonesLarge breastbone

Class AvesFeathers

Class Aves

Endothermy

Class AvesFour-chambered heart

Class AvesBest lungs – one-way respiration

Class Aves

Class Mammalia

Class MammaliaMammary glandsHairSpecialized teeth

Class MammaliaMonotremes

Class MammaliaMarsupials

Class MammaliaEutherians