Vertebrate Animals

DOMAIN- Eukarya KINGDOM- Animalia

–PHYLUM- Chordata • SUBPHYLUM- Vertebrata

–CLASS- 7 different »ORDERS- 10 Placental mammals

Characteristics of ALL vertebrates

• Backbone • Endoskeleton • Distinct Skull • Bilateral Symmetry • Closed circulatory system,

chambered heart

Types of fertilization

Ovoviviparous: internal fertilization of egg, embryo hatches inside the parent, offspring are born live

Oviparous: internal fertilization, eggs are laid externally, offspring hatches externally

Viviparous: internal fertilization with live born young (as soon as the egg is fertilized, it becomes an embryo and develops as a fetus)

Class: Agnatha Hagfish and lampreys

- Jawless & finless - Skeleton of cartilage - Reproduce sexually - Gills - 2 Chambered Heart - Oviparous Hagfish – a detritivore

Lamprey – an ectoparasite

Class: Chondrichthyes Sharks and rays - Endoskeleton made of cartilage - 2 chambered heart - Paired fins - Jaws - Lateral line system (for sensing

vibrations in water—like an “ear”) - Scales - Oviparous, Ovoviviparous, or

Viviparous—depends on species

Class: Osteichthyes

Fish, eels, seahorses, etc…. * One of the most successful groups on Earth – ever!

- Endoskeleton made of bones - Swim bladder - Usually, external fertilization & oviparous (think

caviar) - Lateral line system - Scales different from those in sharks - 2 chambered heart (all fish!)

Class: Amphibia Frogs, toads, salamanders, and newts

- Ectotherms - Need H2O for breeding - Metamorphosis (tadpole frog) - Gas exchange through moist skin & mouth; primitive

balloon-like lungs - External fertilization - Oviparous - 3-chambered heart - Many have chromatophores in the skin for

coloration, as well as poison glands for defense

Class: Reptilia

Turtles, snakes & lizards, crocodiles – Ectotherms – bask and hide to regulate temperature* – Scaly, waterproof skin – Respire through lungs only** – Internal fertilization – Oviparous, ovoviviparous, viviparous (depending on

species) – 3 or 4 chambered heart – Nitrogenous waste is a paste rather than a liquid for

water conservation; uric acid – Extinct reptiles include dinosaurs and pterosaurs, which

dominated the Earth during the Triassic period

Class: Aves Birds

- Endothermic - 4 chambered heart - Internal fertilization - Oviparous - Beaks and claws modified for specific niche - Classified as reptiles by many taxonomists - Digestive system modified for diet, including

crop & gizzard

Modifications for flight: – Feathers are modified scales for flight and insulation – Hollow bones weigh less – Front limbs modified into wings – Air sacs to aid in breathing at high altitudes – Unique muscle tissue for sustained, intense use – Keel : modified breastbone for muscle attachment – Migration: move long distances on a seasonal cycle to reach mating and/or feeding grounds

Class: Mammalia Humans, bears, pigs, horses, dogs, cats, whales, elephants, mice, koalas, platypus

- Endothermic – hair and layer of fat aid in conserving heat

- Hair – keratinous protein that aids in insulation - Mammary glands – produce milk to feed offspring - Internal fertilization

- 2 species of monotreme; oviparous - Marsupials and placentals are viviparous

- 4-chambered heart

Three Categories of Mammals • Monotreme: egg laying mammal

–platypus

• Marsupials: young develops outside the body in a pouch –kangaroo, opossum

• Placental: young develops in uterus –human

Class: Mammalia - Monotreme

• Mammals that lay eggs • Hair • Mammary glands: produce milk to feed young • Platapus, echidna

Class: Mammalia - Marsupial

• Embryo develops in uterus with placenta • Immature fetus is born and finishes

developing inside an external pouch on mother’s body

• Marsupials are found in Australia – Opossum found in Americas

• Offspring develops fully in uterus • Found in every major biome: marine,

terrestrial, arctic • Many orders of placental mammals

– 10 will be discussed…

Class: Mammalia - Placental

Domain : Kingdom : Phylum : Class : Order: Placental Mamalia

Rodentia- razor sharp teeth (rats, squirrels) Lagomorpha- fused hind leg bones (rabbits) Chiroptera- flying mammals (bats) Carnivora- eat meat (lions, tigers, wolves) Cetacea- Blow holes to breathe (dolphins, whales) Insectivora- eat insects (moles, shrews, hedgehog) Artiodactyla- even # of toes (cows, sheep, goat, pigs, hippos, camels) Perissodactyla- odd number of toes (horse, zebra, rhino) Proboscidea- trunks (elephants) Primates- opposable thumbs (apes, monkeys, humans)