Vertebrates

The Origin of TetrapodsThe first vertebrates on land were amphibians in the DevonianMay have arose from the rhipidistian (features) or a lungfish (DNA)

Origin of Tetrapods

ClassificationPhylum: ChordataSubphylum: VertebrataSuperclass: GnathostomataClass: AmphibiaOrder: Urodela (Salamanders)Order: Anurans (Frogs and Toads)Order: Apodans (Caecilians)

Class: AmphibiaTwo lives refers to metamorphosis of many frogsSkin smooth and moist (cutaneous respiration)Three chambered heart with a double circulation systemMesolecithal eggs with jelly-like membrane

Order: Urodela400 speciesSalamandersRetain their tail as adultsLimbs are at right angles to the bodyCarnivorous

Order: Anurans3500 speciesFrogs and ToadsLose their tail as adultsHind limbs are adapted for jumpingTongue connected to front of mouthSecrete mucus

Order: Apodans 150 speciesCaeciliansLegless and blind

Evolution of the Amniotic EggAllows animals to complete their entire life cycle on landHas shell that retains water (or is lost when kept inside mammals)Specialized extraembryonic membranes (not part of the animal)

Evolution of the Amniotic EggAmnion - Protects from dehydration and mechanical shockYolk Sac - Nutrient storageAlbumin - Nutrient storageAllantois - stores waste, gas exchangeChorion - gas exchange

Amniotes

How Reptiles differ from AmphibiansTough, dry skinAmniotic eggCrushing or gripping jawsCopulatory organsMore efficient circulatory system with a higher blood pressureMore developed lungs (thoracic breathing)Better water conservationBetter body support and limbsBetter nervous system

ClassificationPhylum: ChordataSubphylum: VertebrataSuperclass: GnathostomataClass: Reptilia (not real)Class: Testudines (Turtles and Tortoises)Class: Spenodontia (Tuataras)Class: Squamata (Lizards and Snakes)Class: Crocodilia (Crocodiles and Alligators)

Reptile RadiationSynapsids (therapsids) - led to mammalsSauropsidsAnapsids (turtles)Diapsids (all others)

Class: Testudines (Chelonia)Evolved on land and returned to water (lay eggs on land)Protective ShellCarapacePlastron

Class: SphenodontiaTuatarasTwo living species(New Zealand)Not a True Lizard (no external ears)Very Primitive (similar to mesozoic reptilesWell developed eye below skin?

Class: SquamataLizardsgeckos, iguanas, skinks, chameleonsterrestrial, burrowing, aquatic, arborealmoveable eyelidsPaired copulatory organsLower jaw not attached to skull

Class: Squamata

Class: SquamataSnakesLack limbsLack moveable eyelidsJacobsons organPit Vipers (heat)Venomneurotoxinshemolytic enzymes

Class: Squamata

Feeding AdaptationsTeeth curved and pointed inwardHinged Quadrate boneBones of jaw are attached by muscles and ligamentsMoveable palateElastic skinNo sternum

Class: CrocodiliaLargest living reptilesMost closely related to dinosaursComplete secondary palateFour chambered heartNest temperature

Dinosaurs and PterosaursDinosaurs OrnithischianSaurischian (closely related to birds)Pterosaursflying reptiles

Class: Aves

Class: AvesFeathersHollow BonesWingsEndothermOrgans reducedBeak without teethNo bladder

Class: AvesWishbone Called a Furcula made up of the fused clavicles.

Class: AvesMuscles Pectoralis muscle pulls wing downSupracoracoideus raises wing

The Origin of BirdsFeathersBeak with teethLong TailWing with claw

The Origin of BirdsSinoauropteryx - protofeathers?Caudipteryx - true feathers

Bird Classification8600 species of bird (28 orders)60% are passeriformes (perching birds)Two major TypesRatitesOstriches, EmusCarinatesSong birds

Class: MammaliaHairEndothermicMammary glandsLive birth (2 exceptions)Teeth differentiationJaw modified to incorporate bones into inner ear

The Evolution of the MammalReptiles lower jaw made up of several bonesReptiles middle ear made up of one boneMammals lower jaw made up of one boneMammals jaw joint has shiftedMammals middle ear made up of three bones

Mammal ClassificationMonotremeslay eggsno nipples

Monotreme

Mammal ClassificationMarsupialsborn earlydevelops in pouch

Marsupials

Mammal ClassificationPlacentalsEutherian mammalsdevelopment in uterus joined by placenta

Proboscidea

Sirenia

Edentata

Rodentia

Lagomorpha

Carnivora

Artiodactyla

Cetacea

Perissodactyla

Chiroptera

Insectivora

Primate EvolutionAncestral primate (arboreal) (65 mya)binocular visionopposable thumbProsimianslemurs, tarsiers pottos

Primate EvolutionAncestral primate (arboreal) (47 mya)binocular visionopposable thumbIda Missing LinkNo clawsLack a tooth combShort limbsShort faceTalus corner of leg/foot

Primate EvolutionAnthropoids (50 mya)MonkeysOld WorldExternal nares close togetherOpposable thumbsCalloused ischial tuberosities

Primate EvolutionAnthropoids (50 mya)MonkeysNew WorldBroad flat nasal septumNonopposable thumbPrehensile tail

Primate EvolutionHominoids (30 mya)apes

Human EvolutionBrain SizeJaw SizeBipedalismReduced Size difference in sexesFamily Structure

Human EvolutionSahelanthropus(6.5 million years ago)

Human EvolutionLaetoli Footprints(3.5 million years ago)

Human EvolutionAustralopithecus (3.24 million years ago)

Primate EvolutionHomo genus (2.4-1.6 mya)Homo sapiens (200,000 years ago)

Primate EvolutionNeanderthals(40,000 years old)

Human EvolutionTurkana Boy (Homo ergaster)(1.7 million years ago)Between H. habilis and H. erectus

Origin of Modern HumansOut of Africa (monogeneus)all races of humans evolved from an ancestor in AfricaMultiregionalEach race evolved from regional populations of Homo erectus

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Vertebrates