Vertebrates

What is a vertebrate? Vertebrates have... A skull A backbone of vertebrae an endoskeleton of cartilage or bone.

Fish Paired fins Scales Gills

Fish Three groups: a.jawless fish b.cartilaginous c.bony fishes.

Jawless fishes = no teeth or jaw skeletons made of cartilage Include: lamphreys, and hagfish

Cartilaginous fishes. Jaws skeletons of cartilage, scales include sharks, skates and rays.

Bony fishes skeletons of bone Lateral Line system= sensory organ gills to get oxygen. swim bladder to regulate buoyancyswim bladder

Amphibians

(Frogs, toads, salamanders and caecilians) All cold blooded Webbed feet, no claws Non- amniote egg – must be laid near water

Amphibian Characteristics Amphibian means “Double Life”. They are Ectothermic =cold blooded. Hibernate – inactivity in winter

Estivation - inactivity during hot, dry months. mostly breathe through skin= Cutaneous

Must lay their eggs in water, or they’ll dry out.

Metamorphosis- change from a tadpole to frog. Tadpoles – live in water, frogs live near water. Tadpole- tail, gills, no legs Frog- lungs, no tail, legs

Frogs -smooth, slick skin Toads have rough, bumpy skin.

Classification of Amphibians No tail = frogs & toads No feet = Caecilians visible tail = salamanders

© 2001 California Academy of Sciences Reptiles

(Snakes, lizards, turtles and crocodilians) Reptiles have... Toes with claws. Cold blooded. dry, scaly skin, amniotic eggs = eggs with shellsamniotic eggs

Reptiles, continued Reptiles have... Lungs for breathing. internal fertilization.

Reptiles, continued Lizards and Snakes –No eyelids, ears –Swallow prey whole

Turtles 2 shells –Top = Carapace –Bottom = Plastron –No teeth –3 eyelids

Birds

Wings. Feathers. hollow bones. Warm blooded Air sacs

Birds Toothless beak Clawed toes Amniote egg

Mammals hair. Teeth. endothermic = warm blooded. Mostly live birth

Mammals mammary glands that produce milk. internal fertilization

Monotremes Lay eggs 3 species— duckbill platypus, two species of spiny anteaters.

Monotremes Young lap up milk from glands on mom’s belly.

Marsupials give birth to young only days after fertilization.

Placentals most all mammal species. Food provided from inside mom during development

Elephants... long muscular trunk, thick, loose skin and upper incisors that are elongated as tusks.

Sea cows... Manatees and dugongs aquatic herbivores that possess finlike forelimbs,no hindlimbs.

Sloths, Anteaters and Armadillos - Toothless -found only in the Western Hemisphere.

Rodents = Squirrels, beavers, rats, porcupines and mice - chisel-like teeth and continuously growing incisor teeth.

Rabbits, hares and pikas -chisel-like incisors - hind legs longer than forelegs - adapted for running and jumping.

Primates... - opposable thumb, forward-facing eyes, well- developed cerebral cortex, omnivorous.