Animal KingdomVertebrates

6th Grade Science

•“Kings play chess on fine gold sets”

–Kingdom Animalia

–Phylum Chordata

–Class Mammalia

–Order Primate

–Family Homidea

–Genus Homo

–Species sapien

Classification

What is a Chordate?

All chordates have 4 basic features that are present at some point during their life cycle

– Hollow Nerve Cord – Nerve cord in which nerves branch out at regular intervals

– Notochord – Long supporting rod that runs throughout body– Pharyngeal Pouches/Gill Slits – Paired structures in throat– Muscular Tail – Extends beyond anus

Only 4-5% of animals are chordates Examples = Fish, Amphibians, Reptiles, Birds, Mammals

Section 30-1

Nonvertebratechordates

FishesAmphibians

ReptilesBirds

Mammals

Invertebrate ancestor

Chordate Cladogram

Section 30-1

Muscle segments

TailAnus

Pharyngeal pouches

Mouth

Hollownerve cord

Notochord

The Generalized Structure of a Chordate

Vertebrates

Vertebrates have an internal system of bones called an endoskeleton

Ectotherms are cold-blooded animals whose body temperatures change as their environmental temperatures change, e.g. fish, amphibians, reptiles

Endotherms are warm-blooded animals whose body temperatures do not change with changes in their surroundings, e.g., birds and mammals

Fish – Basic Facts

Fish are ectotherms living in nearly every single aquatic habitat Fish are aquatic vertebrates characterized by fins, scales, and gills

Fish were the first vertebrates to evolve some 500 million years ago during the Paleozoic era!!

Fish bring in oxygen rich water through gills and remove oxygen poor water through gill slits; GILLS exchange carbon dioxide for oxygen

Closed circulatory system with two chambered heart Fins help fish steer, balance, and move Scales cover and protect skin Swim bladder controls buoyancy Most are egg laying LARGEST GROUP OF VERTEBRATES!

Fish Classification

Phylum: Chordata– Subphyla:

Urochordata -- sea squirtsCephalochordata -- lanceletsVertebrata -- vertebrates

– Classes:Agnatha -- lampreys and hagfishesChondrichthyes -- sharks and raysOsteichthyes -- bony fishes

Lamprey – Jawless Fish

Catfish - Osteichthyes

Sea Ray - Chondrichthyes

Whale Shark - Chondrichthyes

Osteichthyes

Bony fishes ~ majority of fishes Three subclasses: lungfishes, lobe-finned

fishes, and ray-finned fishes – Have a skeleton made of bone; 95% of all fish– Have a swim bladder or air sac to help control

swimming depth– Carp, sea horse, perch, etc – Flexible skeleton allows for fast speeds– Separate sexes, fertilization external in most

Live-bearers include guppies, mollies, swordfish

Osteichthyes

Agnatha

Hagfishes and Lampreys– Jawless fish w/ slit-like, toothed mouth; feed on dead or dying

fish by drilling a hole and sucking the blood and insides from the animal

– Have mouths of soft tissue with no true teeth.– Have no bones; Only vertebrates with no vertebral column as

adults– Breathe using gills– Reproduce sexually (external fertilization)– Two-chambered heart

blood flow through body is slow, as most of pumping action is used to push blood through gills.

Agnatha

Chondrichthyes

Sharks, Skates, and Rays (living fossils)– Cartilaginous fish w/ skeleton of cartilage– Paired fins for balance, swimming, and steering– Evolution of jaws

Sharks -- 6-20 rows of teeth, continually replaced

– Highly developed sensory systems extremely sensitive sense of smell lateral line system -- detects movement and vibrations in

water (line of fluid-filled canals)

– Internal fertilization -- eggs kept inside body when young are released, they behave like mini-adults

Amphibian Classification

Phylum: Chordata Class: Amphibia Order:

– Urodela -- salamanders and newts– Anura -- frogs and toads– Apoda -- legless caecilians

Groups of Amphibians

Salamanders – – Long bodies and tails– Adults are carnivorous– Usually live in moist woods

Frogs and Toads – – Lack tails– Frogs have long legs and are usually tied to water– Toads have shorter legs and not as closely tied to water

Caecilians –– Legless animals that burrow in moist soil– Have fishlike scales

Spotted Salamander

Poison Dart Frog

Fire Bellied Toad Caecilian

Amphibian Characteristics

Spend part of their lives on land and part in water, but nearly all rely on water for breeding

Adaptations – adjustments for temperature Ectotherms -- body temperature changes with

temperature of the surroundings– Hibernation – inactivity during cold weather– Estivation – inactivity during warm weather

Three-chambered heart ~ skin very important as an organ for gas exchange

Amphibian Characteristics

Endoskeleton made of bones to support body on land

Lungs to breathe on land; also exchange oxygen and carbon dioxide through the skin

Hearing and vision adapted to land life Long tongue captures insects for food Descendants of ancestral organisms that evolved

some, not all, adaptations for life on land First appeared 360 million years ago

Amphibian Metamorphosis

Hatched from eggs fertilized in water; tadpoles live in water and breathe through gills

Land-function structures such as legs and lungs develop for land life

Section 30-3

Adult FrogAdult Frog

Young FrogYoung Frog

Fertilized EggsFertilized Eggs

TadpolesTadpoles

Adults are typically ready tobreed in about one to two years.Adults are typically ready tobreed in about one to two years.

Frog eggs are laid in water andundergo external fertilization.Frog eggs are laid in water andundergo external fertilization.

The eggs hatch into tadpoles a few days to several weeks later.

The eggs hatch into tadpoles a few days to several weeks later.

Tadpoles gradually grow limbs, lose their tails and gills, andbecome meat-eaters as they develop into terrestrial adults.Tadpoles gradually grow limbs, lose their tails and gills, andbecome meat-eaters as they develop into terrestrial adults.

The Life Cycle of a Frog

that allow for

are

that providethat allow

are

and have special adaptations such as

larvae they live in adults they live on

Section 30-3

means

as

Efficientmovement

Breathingair

Support andprotection

Bones Lungs Ribs

Amphibians

Water Land

“Double life”

Reptiles – Basic Facts

Ectothermic animals that generally live whole lives on land Body plans vary, but all reptiles have:

– Dry, scaly skin – helps prevent loss of body water in dry environments

– Terrestrial eggs – first animals to develop amniotic eggs that didn’t need to be deposited in water

Respire using lungs Internal Fertilization; Most are egg-laying Behavior controls body temp. (swimming, burrowing, basking,

etc.) Closed circulatory system; double loop; Heart = two atria/one or two ventricles

Reptiles – Basic Facts

Some reptiles, such as turtles, use a hard shell for protection; turtles eat insects, worms, fish, plants

Some, such as alligators or crocodiles, live in or near water Some, such as lizards and snakes, use their tongues to smell

their environment; no ears – feel vibrations on ground Reptile adaptations:

– Thick, dry skin covered with scales protects and reduces water loss

– Breathe using lungs– Internal fertilization produces amniotic egg that nourishes and

protects the young until they hatch, fully developed

Groups of Reptiles

Lizards and Snakes– Have legs & clawed toes (lizards) external ears, moveable

eyelids– Highly evolved specialized forms (venom)

Crocodiles and Alligators– Long, typically broad snout and squat appearance– All are carnivorous– Protective of young; carry hatchlings in their mouth– Live in tropics and subtropics– Alligators live in freshwater– Crocodiles live in fresh or saltwater

Groups of Reptiles (con.)

Turtles and Tortoises –– All are shelled– Turtles are aquatic; tortoises are terrestrial

Tuatara – – Primitive reptiles found on small, remote islands

Coral Snake Sea Turtle

Galapagos Tortoise

Tuatara

Nile CrocodileNorth American Alligator

Birds – Basic Facts

Endothermic vertebrates that have two wings, two legs, a bill or beak, feathers, and lay eggs

Nearly 10,000 modern bird species Birds are closely related to reptiles (scales on legs) Feathers separate birds from all other animal species Feathers provide insulation for warmth; can generate on body

heat Beak/Bills adapted to type of food they eat Highly efficient respiratory system; lungs only exposed to

Oxygen rich air Internal fertilization; amniotic eggs; many mate for life

Birds – Basic Facts

Adaptations for flight:– Strong, hollow bones– High-energy diet– Large, efficient heart and a specialized respiratory system– Lungs with air sacs for efficiency and light weight– Wing shape and surface area, and air speed and angle

combine with wing movements to provide an upward push for flight

– Wing shape, area, and speed determine amount of lift produced!

Birds – Basic Facts

Functions of Feathers– Strong, lightweight contour feathers give adult birds their

stream-lined shape and coloring Barbs: parallel strands off the main shaft Help bird steer in air or swim Attract mates or protect bird from predators

– Down feathers – insulating layer of fluffy feathers under contour feathers

– Feather care – preening adds oil for water-repellency; also closes breaks or gaps in feathers (oil gland found at base of tail)

Section 31-2

which are that also that power that provide that ensure

have the followingadaptations to flight

Birds

Homologous tofront limbs in other

vertebrates

Providewarmth

Upward anddownward wing

strokes

One-way flowof O2-rich air

O2 distributionto body tissues

Wings FeathersStrong chest

muscles

Efficientrespiratory

system

Efficientcirculatory

system

Groups of Birds

More than thirty orders of birds Some of the most common

– Perching Birds – largest order; many are songbirds (sparrows, crows, cardinals, etc.)

– Birds of Prey – fierce predators with hooked bills; large talons (condors, hawks, owls, eagles, etc.)

– Herons & Relatives – Wade in aquatic habitats (storks, herons, cranes)

– Ostriches & Relatives – flightless birds move by running or swimming (ostriches, emus, etc.)

Purple Finch

Red-Tailed Hawk

Stork

Emu

Mammals – Basic Facts

Endothermic vertebrates with mammary glands and hair First true mammals appeared 220 million years ago Mammals flourished after dinosaurs became extinct – 65 million years ago Basic characteristics

– Hair– Mammary glands – produce milk to nourish young– Breathe air– Four chambered heart– Endotherms – can generate own body heat– Internal fertilization; care for young– Specialized teeth

Herbivores: plant-eating animals with incisors for cutting and molars for grinding Carnivores: meat eaters with sharp canines for tearing flesh Omnivores: eat both plants and animals using a variety of teeth

Mammals – Basic Facts

Body Systems– Well developed lungs made of millions of microscopic sacs called alveoli,

which enable the exchange of carbon dioxide and oxygen during breathing

– Large brain and complex nervous system– Internal fertilization to form embryo

Monotremes (platypus – lay eggs) Marsupials Placentals

Mammal Types

Monotremes: lay eggs and lack nipples on mammary glands Marsupials: give birth to immature young that finish developing in a

pouch, e.g., opossums, kangaroos, koalas, Tasmanian devils, and wallabies

Placentals: develop from embryos connected to a placenta by an umbilical cord

– Placenta provides food and oxygen to embryo and removes its waste– Time of development in uterus is called gestation period

Humans: 280 days Mice and rats: 21 days Elephant: 616 days

Mammals Today

More than 4,000 species of mammals exist on Earth today Found on every continent and in every climate Have a role in maintaining environmental balance Many mammals are endangered due to destruction of their habitat

Orders of Placental MammalsOrders of Placental Mammals

Order

Insectivores

Sirenians

Cetaceans

Chiropterans

Rodents

Order

Insectivores

Sirenians

Cetaceans

Chiropterans

Rodents

Section 32-2

Characteristics Examples

Long, narrow snouts, sharp claws

Water-dwelling, slow-moving

Live and breed in ocean, come to surface to breathe

Winged, capable of true flight

Single pair of long, curved incisor teeth in upper and lower jaws

Shrews, hedgehogs, moles

Manatees, dugongs

Whales, dolphins

Bats

Mice, rats, voles, squirrels, beavers, porcupines, chinchillas

Orders of Placental MammalsOrders of Placental Mammals

Order

Perissodactyls

Carnivores

Artiodactyls

Proboscideans

Order

Perissodactyls

Carnivores

Artiodactyls

Proboscideans

CharacteristicsCharacteristics ExamplesExamples

Section 32-2

Hoofed, with an odd number of toes on each foot

Sharp teeth and claws

Hoofed, with an even number of toes on each foot

Trunks

Horses, tapirs, rhinoceroses, zebras

Tigers, hyenas, dogs, foxes, bears, raccoons, walruses

Cattle, sheep, goats, pigs, ibex, giraffes, hippopotami, camels

Asian and African elephants, mastodons and mammoths

Orders of Placental MammalsOrders of Placental Mammals

Order

Lagomorphs

Xenarthrans

Primates

Order

Lagomorphs

Xenarthrans

Primates

CharacteristicsCharacteristics ExamplesExamples

Section 32-2

Two pairs of incisors in upper jaw, hind legs allow leaping

No teeth (or very small teeth in the back of the jaw)

Highly developed cerebrum and complex behaviors

Snowshoe hares, rabbits

Sloths, anteaters, armadillos

Lemurs, tarsiers, apes, gibbons, macaques, humans