Vertebrates

Vertebrates

Characteristics:EndoskeletonSegmentationBilateral symmetryTwo pairs of jointed appendagesCephalizationBrains and sense organsVERTEBRAE

First Vertebrates

Fishes that first appeared about 500 million years ago

Called Agnathans- had no jaws or paired fins Lead to the development of jawless fishes

Characteristics of All Fishes

GillsChambered heart (closed system 3 main

chambers)Single loop circulatory systemKidneys Either Male or Female

Jawless Fishes

Mouth but no jawsCartilaginous skeletonsEel like Unpaired finsSuction cup like mouthIncludes:1.Lampreys2.Hagfish

Hagfish

lamprey

Cartilaginous Fishes

Have jawsHave teeth (which are modified scales set in

rows)Cartilaginous skeleton (light weight but very

strong; made of calcium carbonate)Internal fertilization Most give live birthIncludes:1.Sharks 2.Skates3.Rays

Skates

Rays

Bony Fishes

Skeletons are made boneDeveloped lateral line system: sensory systems

that extends along the each side of their bodies;1.allows them to know where their body is in

relation to the water; depth, and place;2.allows the to sense objects not moving in the

waterSwim bladder: allows them to move deeper or

shallower by adjusting the amount of gas in the bladder

Operculum: gill covers

Amphibians

Characteristics:LegsLungsDouble loop circulationCutaneous respiration (ability to breathe

through the skin)3 chambered heart (oxygenated and

deoxygenated blood mix in the heart, that’s what makes them cold blooded)

IncludesFrogsToadsSalamandersCaecilians

Salamanders

Caecilians

Reptiles

Class ReptiliaIncludes lizards, snakes, turtles, tortoises,

crocodiles and alligatorsFound through out the world except in the coldest

regions. Why?Have bone skeleton with the legs more directly

under their body. Allows reptiles to move on land easier than amphibians

Ectothermic metabolismDry scaly skin- almost water tightAmniotic eggs

Reptiles

LungsVentricle of heart partly divided by septum.

Oxygen poor and oxygen rich blood mix. Crocodiles have a completely separated heartInternal fertilzation Oviparous – young hatch from eggs. Some species are ovoviviparous – female

retains eggs inside her body until shortly before hatching. Offspring are more able to fend for themselves and less vulnerable to predators

Snakes Reptiles Lizards

Turtles Reptiles Tortoises

Alligators Reptiles Crocodiles

Birds

Class AvesForelimbs modified into wingsBody covered in feathers (modified reptilian

scales, used for flight and insulation)Lightweight bones (thin and hollow, many are

fused to make more rigid)Endothermic metabolism (4 chambered

heart) (body temperature range from 40-42 degrees C)

Birds

Super efficient respiratory systemYoung are hatched from eggsInternal fertilization Body sizes and shapes are adapted to

environment the bird lives in, main source of food, and main means of escaping predators

Mammals

Class Mammalia HairEndothermic metabolism (4 chambered heart)Mammary glands (produce milk to nurse young)Live birth Teeth size and shape are determined by food.

(herbivore’s teeth are flat for grinding, carnivore’s teeth are sharp for ripping and tearing food)

Mammals

Very diverse groupYou have the Monotreme (platypus)MarsupialsPlacental mammals (young develop within the

females uterus where the placenta allows for diffusion of nutrients from the mothers blood to the young)

Order Rodentia (mice, rats, beavers)

Order Chiroptera (flying mammals, bats)

Order Insectivora (insect eaters, shrews)

Order Carnivora (cats, canines, bears, raccoons)

Order Pinnipedia (marine carnivores, seals, sea lions, walrus)

Order Primates

Order Artiodactyla(ungulates, mammals with even toed

hoofs, pigs, sheep, goats, camels, deer, giraffes)

Order Perissodactylaungulates with odd number toes

horses, zebras, rhinoceroses

Order Cetacea

2 groupsPredatory toothed whales, dolphins,

porpoisesFilter feed baleen whales

Order Cetacea

Order Lagomorpharabbits and hares

Order Sireniadugongs, manatees

Order ProboscideaElephants