Phylum Chordata Charactertistics of ChordatesCharactertistics of Chordates All chordates possess a notochord.All chordates possess a notochord. Long felxable.

Phylum ChordataPhylum Chordata•Charactertistics of ChordatesCharactertistics of Chordates•All chordates possess a All chordates possess a notochordnotochord..•Long felxable rod between gut & nerve cordLong felxable rod between gut & nerve cord•Runs most of length of animalRuns most of length of animal•Possess a dorsal, hollow, Possess a dorsal, hollow, nerve cordnerve cord•Possess Possess pharangeal slitspharangeal slits•Muscular post-anal tailMuscular post-anal tail

UrochordatesUrochordates

• Subphylum Subphylum UrochordataUrochordata• Commonly called Commonly called

turnicatesturnicates• Sessile marine animals Sessile marine animals

as adults - Motile as larvaas adults - Motile as larva• Larva possess a clear Larva possess a clear

notochord which is less notochord which is less evident in adultsevident in adults

• Filter feed through use of Filter feed through use of siphon siphon

Subphylum Subphylum CephalochordataCephalochordata

• Commonly known as Commonly known as lancetslancets

• Have all features of Have all features of the ideal chordatethe ideal chordate

• Bury selves in sand, Bury selves in sand, and filter-feed through and filter-feed through mouthmouth

Phylum Chordata: The Phylum Chordata: The VertebratesVertebrates

• Subphylum VertebrataSubphylum Vertebrata

• Seven Seven extantextant classes classes

• First 3 commonly called fishesFirst 3 commonly called fishes

• Remaining 4 called Remaining 4 called tetrapodstetrapods (4 feet) (4 feet)

• All possess some form of segmented All possess some form of segmented vertebravertebra

Class AgnathaClass Agnatha• Commonly known as Commonly known as Jawless FishJawless Fish• Include Include hagfishhagfish & & LampreysLampreys• Lack paired appendagesLack paired appendages• Lack bony skeletonLack bony skeleton• Lack jawsLack jaws

– Usually have circular sucking mouthpartsUsually have circular sucking mouthparts• Lampreys parasitize other fishLampreys parasitize other fish

LampreysLampreys

HagfishHagfish

Class ChondrichthyesClass Chondrichthyes

• Include Include sharkssharks & & skatesskates, & , & raysrays• Very successful classVery successful class• Called Called cartilagenouscartilagenous fishes because skeleton is fishes because skeleton is

cartilage not bonecartilage not bone• Approx. 750 speciesApprox. 750 species• Have paired appendagesHave paired appendages• Many have acute sensesMany have acute senses• Sharks have a Sharks have a lateral-linelateral-line system system• Allows shark to detect water pressure changes Allows shark to detect water pressure changes

SharksSharks

Noteworthy Shark SpeciesNoteworthy Shark Species

Great White SharkGreat White SharkTiger SharkTiger Shark

Whale SharkWhale Shark Bull SharkBull Shark

Rays & SkatesRays & Skates

Manta RayManta Ray Southern StingraySouthern Stingray

SkatesSkates

Class OsteichthesClass Osteichthes• Called Bony fishCalled Bony fish• Most diverse of all fishMost diverse of all fish• Have skeleton made of boneHave skeleton made of bone• Have Have Cycloid ScalesCycloid Scales• Have paired finsHave paired fins• Allowed evolution of 4 limbed amphibians (Allowed evolution of 4 limbed amphibians (tetrapodstetrapods))• Possess scales for protectionPossess scales for protection• Have bony flap called Have bony flap called operculumoperculum

– Allows water to be drawn over gills by finsAllows water to be drawn over gills by fins• Have Have Swim bladderSwim bladder

– Gas content can be manipulated allowing for changes in bouyancyGas content can be manipulated allowing for changes in bouyancy

BluefishBluefish

Class AmphibiaClass Amphibia

• First vertebrates to inhabit landFirst vertebrates to inhabit land

• Most are 4 limbed (Most are 4 limbed (tetrapodstetrapods))

• Include Include frogsfrogs, , salamanderssalamanders & & caecilianscaecilians

• Have 3 chambered heartHave 3 chambered heart

• Have more complicated gas exchange Have more complicated gas exchange organs (often a combination of lungs, gills organs (often a combination of lungs, gills and skin)and skin)

Order UrodelaOrder Urodela(Salamanders & Newts)(Salamanders & Newts)

• UrodelaUrodela ("tailed ones" - Salamanders) ("tailed ones" - Salamanders)• More dependent on waterMore dependent on water• Many species possess gills as adults Many species possess gills as adults

Class Apoda Class Apoda ("tail-less ones" - Frogs & toads)("tail-less ones" - Frogs & toads)

• Have more developed Have more developed lungs than salamanderslungs than salamanders– Lack a Lack a diaphragmdiaphragm & must & must

“swallow” air“swallow” air

• Most diverse and Most diverse and common of amphibians.common of amphibians.

• Toads are the first Toads are the first amphibians to evolve amphibians to evolve keratinizedkeratinized skin. skin.– This waterproofs the skin This waterproofs the skin

preventing water losspreventing water loss

• Toads must still return to Toads must still return to water to lay eggs.water to lay eggs.

Common North American FrogsCommon North American Frogs

North American ToadNorth American Toad Green FrogGreen Frog BullfrogBullfrog

Leopard FrogLeopard Frog PeepersPeepers

Poison Arrow FrogPoison Arrow Frog

Caecilia ("legless ones")Caecilia ("legless ones")

ReproductionReproduction

• Lack Lack internal internal fertilizationfertilization & & amniotic amniotic eggseggs

• Reproduction must occur Reproduction must occur in H2Oin H2O

• Most species undergo Most species undergo metamorphosismetamorphosis– Larval stage (tadpole) is Larval stage (tadpole) is

usually an aquatic usually an aquatic herbavoreherbavore

– Lacks legs, respiration is Lacks legs, respiration is through gillsthrough gills

– Develops into Develops into tetrapodtetrapod adult (usually carnivorous)adult (usually carnivorous)

Class ReptiliaClass Reptilia• Includes Includes lizards, snakes, turtles, and crocodilianslizards, snakes, turtles, and crocodilians• Over 7000 speciesOver 7000 species• Possess several advanced features over amphibiansPossess several advanced features over amphibians• Most adaptations towards independence from HMost adaptations towards independence from H22OO• Possess scales containing Possess scales containing keratinkeratin• KeratinKeratin is a waterproofing protein which prevents water is a waterproofing protein which prevents water

loss in an organismloss in an organism• Possess an Possess an amniotic eggamniotic egg..

– Prevents water loss of embryo. Allows for eggs to be laid on dry Prevents water loss of embryo. Allows for eggs to be laid on dry landland

• Combined with Combined with internal fertilizationinternal fertilization, allows reptiles to , allows reptiles to reproduce independently of waterreproduce independently of water

• Reptiles are "cold blooded" or Reptiles are "cold blooded" or ectothermsectotherms– Cannot internally regulate body temperaturesCannot internally regulate body temperatures– Reptiles can regulate body temperatures behaviorally (eg. Reptiles can regulate body temperatures behaviorally (eg.

Basking or swimming)Basking or swimming)– Nutritional requirements are lower than warm blooded animalsNutritional requirements are lower than warm blooded animals

The Amniotic EggThe Amniotic Egg

Modern ReptilesModern Reptiles

• Order Order CheloniaChelonia (Turtles (Turtles & Tortoises)& Tortoises)– Inhabit aquatic and Inhabit aquatic and

terrestrial environment.terrestrial environment.– Are herbavores, Are herbavores,

carnivores, and omnivorescarnivores, and omnivores– Characterized by Characterized by

possessing a hard possessing a hard dorsal dorsal shellshell

– Made from bone, Made from bone, extensions of backbone extensions of backbone and rib cage and rib cage

Common North American TurtlesCommon North American Turtles

Order SquamataOrder Squamata

• Order Order SquamataSquamata (Lizards & Snakes) (Lizards & Snakes)

• Most numerous & diverse of the reptilesMost numerous & diverse of the reptiles

• Most relatively small Although monitors Most relatively small Although monitors and their relatives can grow to 6' in lengthand their relatives can grow to 6' in length

• Herbivores, carnivores & omnivoresHerbivores, carnivores & omnivores

• Most able to exhibit some form of Most able to exhibit some form of hibernation hibernation

Noteworthy LizardsNoteworthy Lizards

Eastern Fence LizardEastern Fence Lizard

Leopard GeckoLeopard Gecko

Komodo DragonKomodo Dragon

AnoleAnole

North American SnakesNorth American Snakes

Order Order CrocodiliaCrocodilia (Crocodiles, Alligators, & Caimans)(Crocodiles, Alligators, & Caimans)

• Largest extant reptiles can grow to over 15’ and weigh over a Largest extant reptiles can grow to over 15’ and weigh over a tonton

• Primarily aquatic they are true reptilesPrimarily aquatic they are true reptiles• Inhabit warm, tropical climatesInhabit warm, tropical climates• Order most closely related to the dinosaursOrder most closely related to the dinosaurs

CrocodiliansCrocodilians

CrocodileCrocodile AlligatorAlligator

CaimanCaiman GavailGavail

Class AvesClass Aves(The Birds)(The Birds)

• Evolved from dinosaurs during Mezozoic era.

• Aminotic eggs and scales on legs reminants of reptilian origins

• Almost all adaptations of these animals are made for flight.

• Presence of feathers– Made of keratin– Can be used for insulation and

flight• Forelimbs developed into

wings• Honeycombed, light bone

structure

FeathersFeathers

Beak TypesBeak Types• Absence of some organsAbsence of some organs

– Females usually have 1 ovaryFemales usually have 1 ovary– Absence of teeth lighten headAbsence of teeth lighten head– Replaced by Replaced by gizzardgizzard in abdomen & in abdomen & beakbeak

• Beak made of keratinBeak made of keratin– Proven very adaptable structure, having a variety of shapes for differing dietsProven very adaptable structure, having a variety of shapes for differing diets

ReproductionReproduction

•Reproduction is through hardened amniotic eggsReproduction is through hardened amniotic eggs•Since birds are endothermic, these must be kept warm by Since birds are endothermic, these must be kept warm by parentsparents•This behavior called This behavior called broodingbrooding

Birds FeetBirds Feet

Modern BirdsModern Birds

• Over 8600 species & 20 Over 8600 species & 20 orders of birdsorders of birds

• Classified into 2 general Classified into 2 general groupsgroups

• Flightless species Flightless species including ostrich, emus, & including ostrich, emus, & kiwis are known as kiwis are known as ratitesratites

• Lack Lack sternal keelsternal keel on on breastbonebreastbone

• Lack strong breast Lack strong breast muscles needed for flightmuscles needed for flight Ostrich: A ratiteOstrich: A ratite

Modern birds contd.Modern birds contd.

• Other species capable of Other species capable of supporting flight called supporting flight called carinatescarinates

• 60% are "perching birds" 60% are "perching birds" called called passeriformspasseriforms

• Possess a Possess a sternal keelsternal keel on breastboneon breastbone

• Support strong breast Support strong breast muscles required for flightmuscles required for flight

The sparrow: A passeriform carinateThe sparrow: A passeriform carinate

Class mammaliaClass mammalia• Approx. 4500 species of mammalsApprox. 4500 species of mammals• Evolved from mammal-like reptiles called Evolved from mammal-like reptiles called therapsidstherapsids in the in the triassictriassic

periodperiod• Diversified greatly following the extinction of dinosaursDiversified greatly following the extinction of dinosaurs• Mammilian CharacteristicsMammilian Characteristics

– Have HairHave Hair• Made of keratinMade of keratin• Aids in maintaining body temperatureAids in maintaining body temperature

• EndothermicEndothermic– Maintain body temperature internallyMaintain body temperature internally

• Have efficient respiratory system including a Have efficient respiratory system including a diaphragmdiaphragm• Efficient circulatory system with a 4-chambered heartEfficient circulatory system with a 4-chambered heart• Most possess Most possess placentasplacentas and give birth to live young and give birth to live young• Have Have mammary glandsmammary glands to produce to produce milkmilk for offspring for offspring• All show parental care of offspringAll show parental care of offspring• Have largest brains of all vertebratesHave largest brains of all vertebrates• Have Have differentiated teethdifferentiated teeth

– Unlike earlier vertebrates, several different teeth can exist in mammal jawsUnlike earlier vertebrates, several different teeth can exist in mammal jaws– Eg. The molars & incisors in the human jawEg. The molars & incisors in the human jaw

General Types of MammalsGeneral Types of Mammals

• MonotremesMonotremes– Early branch from Early branch from

reptilian linereptilian line– Include Include platypusesplatypuses & &

echidnasechidnas (spiny (spiny anteaters)anteaters)

– Only group to lay eggs Only group to lay eggs (reptilian in structure)(reptilian in structure)

– Have mammary Have mammary glands to feed youngglands to feed young

Duck Billed PlatypusDuck Billed Platypus

EchidnaEchidna

MarsupialsMarsupials

• Include opossums, kangaroos & koalasInclude opossums, kangaroos & koalas• Mostly found in Australia & New ZealandMostly found in Australia & New Zealand

– Were isolated in these landmasses when the Were isolated in these landmasses when the continents separated and did not evolve li the same continents separated and did not evolve li the same way placental mammals didway placental mammals did

• Do not develop placentasDo not develop placentas• Give birth to young very earlyGive birth to young very early• Fetuses complete development in pouch called Fetuses complete development in pouch called

marsupiummarsupium• Mammary glands found in pouch nourish young Mammary glands found in pouch nourish young

until development is completeuntil development is complete

Examples of marsupialsExamples of marsupials

OpossumOpossum

KoalaKoala

KangarooKangaroo

Placental MammalsPlacental Mammals

• Complete embryonic development in uterusComplete embryonic development in uterus• Joined to parent by organ called Joined to parent by organ called placentaplacenta

– Only "disposable" mammal organOnly "disposable" mammal organ– Discarded following birthDiscarded following birth– Exchanges gasses, nutrients & waste between mother and fetusExchanges gasses, nutrients & waste between mother and fetus

Common North American Mammals 1Common North American Mammals 1

Common North American Mammals 2Common North American Mammals 2