Taxonomy of Vertebrates

PHYLUM

CHORDATATAXONOMY

From Kent and Carr

and Hyman

Phylum Chordata

• Characteristics of Phylum Chordata:

• The wall of the pharynx of an embryo or adult is pierced with openings (gill slits);

endostyle (a glandular groove in the floor of the pharynx)

• Presence of notochord in embryo or adult

• Central Nervous System is hollow

• Postanal Tail

Phylum Chordata• SUBPHYLUM:

• Subphylum Urochordata- tunicates

• Subphylum Cephalochordata- Amphioxus, lancelets

• Subphylum Craniata- all chordates with endoskeleton of cartilage or bone or both

Pandocia sp.

Branchiostoma lanceolata

Phylum Chordata

Subphylum Urochordata

• Tunicates

• notochord in tail region

• notochord and nerve cord present in

larvae

• e.g. Pandocia sp.

Subphylum Cephalochordata

• lancelets; marine animals that are

segmented, elongated, fish like

body

• e.g. Branchiostoma lanceolata

Subphylum Urochordata

• Class Ascidiacea

• Class Larvacea (Appendicularia)

• Class Thaliacea

Class LarvaceaPegea confederate

Salp

Class Thaliacea

Polycarpa aurata

Ox Heart Ascidian

Class Ascidiacea

Subphylum Cephalochordata

• Branchiostoma

• Asymmetron

Branchiostoma lanceolata

Epigonichthys maldivensis

Subphylum Craniata

• Superclass Agnatha- without jaws

• Superclass Gnathostomata- with jaws

FISHES AND FISH-LIKE

ANIMALS• Cold-blooded aquatic vertebrates

• Fins for locomotory organs

• Gills as respiratory organs

• Vertebral axis ends with a vertical fin

• Heart with 1 atrium and ventricle

• Embryo with no membranes (except yolk sak)

Superclass Agnatha

• Class Myxini- hagfishes

• Suborder Myxnoidea- hagfishes

• nasohypophyseal aperture terminal

• canal opening into pharynx

• branchial basket vestigial

• e.g. Bdellostoma, Myxine

• Class Pteraspidomorphi (Diplorhina)

• Order Pteraspidiformes (Hetrostraci)

• Order Thelodontiformes (Coelolepida)

• Order Galeaspidiformes

• ** EXTINCT! Characteristic: Heavy armored fishes!

• Fish-like animals

• Without jaws

• No or poorly developed fins

Cyclostomata

• round mouthed fishes

• naked/slimy skin

• round jawless mouth

• suckers

• w/o paired fins

• a row of gill slits

• single median nasal sac

• nasohypophyseal aperture and canal

* Often confused as a class or order

Superclass Agnatha

• Class Cephalaspidomorphi (Monorhina)

• Order Petromyzontiformes- lampreys

• Suborder Petromyzontia

• nasohypophyseal aperture dorsal

• presence of branchial basket

• e.g. Petromyzon, Lampreta

• Order Cephalaspidiformes (Osteotraci)

• Order Anaspidiformes

** EXTINCT! Characteristic: Heavy armored fishes!

**also known as ostracoderms

• Fish-like animals

• Without jaws

• No or poorly developed fins

Cyclostomata

• round mouthed fishes

• naked/slimy skin

• round jawless mouth

• suckers

• w/o paired fins

• a row of gill slits

• single median nasal sac

• nasohypophyseal aperture and canal

* Often confused as a class or order

Order Galeaspidiformes

Order Cephalaspidiformes (Osteotraci) Order Pteraspidiformes (Hetrostraci)

Order Thelodontiformes (Coelolepida)

Order Anaspidiformes

Bdellostoma polyrema – Chilean Hagfish

Myxine glutinosa – Atlantic Hagfish

Lampreta fluviatilis Linn.

Petromyzon marinus – Sea Lamprey

Superclass Gnathostomata

• Class Acanthodii

• extinct; spiny Paleozoic fishes

• Class Placodermi

• extinct fishes with jaws and a full-sized hyoid gill slits;

armored

• e.g. Antiarchs, Arthrodires

• Class Chrondrichthyes- cartilaginous fishes

• sharklike fishes with jaws and paired fins

• skeleton wholly cartilaginous

• no membrane bones

• hyoid slits reduced

• exoskeleton of small scales; homologous to teeth

• no lungs or air bladder

-jawed vertebrate

Class Chrondrichthyes• Subclass Elasmobranchii

• Order Cladoselachiformes- Cladoselache

• Order Squaliformes- squalouslike sharks

• Order Rajiformes- skates, sawfishes, and rays

• Order Carcharhiniformes- Requiem Shark

• Order Heterodontiformes- Port Jackson Shark

• Order Hexanchiformes- Sixgill Shark

• Order Lamniformes- Great White Shark

• Order Orectolobiformes- Nurse Shark

• Order Pristiophoriformes- Sawshark

• Order Squantiniformes- Angel Shark

• cartilaginous fishes

• sharklike

Subclass Elasmobranchii

• naked gill slits

• hyostylic type of upper-jaw

suspension

• with spiracles

• Pelvic fins of males have claspers

Squalus acanthias- Spiny Dogfish Order SqualiformesOrder Cladoselachiformes

Order Rajiformes

Leucoraja erinacea –Little Skate

Order Carcharhiniformes

Galeocerdo cuvier – Tiger Shark

Order Heterodontiformes

Heterodontus portusjacksoni- Port Jackson

Shark

Hexanchus griseus – Bluntnose Sixgill

Shark

Order Hexachiformes

Order Lanmiformes

Carcharodon carcharias –Great White Shark

Ginglymostoma cirratum – Nurse Shark

Order Orectolobiformes

Squatina squatina- Angelshark

Order Squatiniformes

Pristis pectinate- Smalltooth Sawshark

Order Pristiformes

Triakis scyllium- Banded Houndshark

Raja sp.

Rhinobatos punctifer – Spotted Guitarfish

Torpedo sp.Raja sp.

Class Chrondrichthyes

• Subclass Holocephali

• gill slits concealed under operculum (non-bony skin flap)

• naked skin

• absent spiracle

• immovable holostylic jaw suspension

• flat bony plates in place of teeth

• claspers

• e.g. Chimaera

• cartilaginous fishes

• sharklike

Chimaera monstrosa

Rabbit Fish

Chimaera cubana- Cuban chimaera.


-jawed vertebrate

Superclass Osteichthyes

• bony fishes

• skeleton ossified

• chrondocranium, jaws, and pectoral girdle incased in dermal bones

• scales/rhomboid plates

• gills covered by a bony operculum

• air bladder= lungs

• no claspers

• Class Sacropterygii (Choanichthyes)- lobed-

finned fishes

• Superorder Crossopterygii

• paired fins with a rounded basal lobe

• two dorsal fins

• hyostylic jaw suspension

• e.g. Latimeria, Osteolepis

• Superorder Dipnoi- Lungfish

• paired fins with elongated jointed axis bearing side

branches

• autostylic jaw suspension; spiracle absent

• with tooth plates

• e.g. Neoceratodus, Protopterus, Lepidosiren

Latimeria chalumnae - West Indian Ocean

coelacanth

Osteolepis

Superorder Crossopterygii

Neoceratodus forsteri – Queensland Lungfish

Protopterus annectens

African Lungfish

Lepidosiren paradoxa

South American Lungfish

Superorder Dipnoi


-jawed vertebrate

Superclass Osteichthyes

• bony fishes

• skeleton ossified

• chrondocranium, jaws, and pectoral girdle incased in dermal bones

• scales/rhomboid plates

• gills covered by a bony operculum

• air bladder= lungs

• no claspers

• Class Actinopterygii- ray-finned fishes

• paired without axis or basal lobes

• one dorsal fin

• w/o cloaca


• Subclass Chrondrostei

• Subclass Neopterygii

• Subclass Teleostei

Superclass Osteichtyes

-bony fishes

Class Actinopterygii

• ray-finned fishes

• paired without axis or basal

lobes

• one dorsal fin

• w/o cloaca


• Subclass Chrondrostei- cartilaginous endoskeleton

• Order Palaeonisciformes

• Order Polypteriformes- pectoral fins w/ basal lobes

• e.g. Polypterus, Calamoichthys

• Order Acipenseriformes- fins are not lobed

• e.g. Acipenser, Polyodon

• Subclass Neopterygii- ganoids

• Order Lepisosteiformes

• thick ganoid scales of rhombic shape

• e.g. Lepidosteus

• Order Amiiformes

• thin and round cycloid scales

• e.g. Amia

Polypterus endlicheri endlicheri –Saddled Bichir

Calamoichthys calabaricus

Order Polypteriformes

Acipenser oxyrinchus oxyrinchus- Atlantic Sturgeon

Polyodon spathula – American Paddlefish

Order Acipenseriformes

Amia calva – Bowfish

Lepisosteus osseus – Longnose Gar

Order Lepisosteiformes

Order Amiiformes

Superclass Osteichtyes

-bony fishes

Class Actinopterygii

• ray-finned fishes

• paired without axis or basal

lobes

• one dorsal fin

• w/o cloaca


• Subclass Teleostei- modern ray fishes; typical

bony fishes

• Order Clupeiformes

• e.g. herring, sardines

• Order Cypriniformes

• e.g. minnows, carps, goldfish

• Order Anguilliformes

• e.g. eels

• Order Gadiformes

• e.g. codfishes

• Order Perciformes

• e.g. perchlike teleosts

Clupea harengus – Atlantic Herring Sardina pilchardus

European Pilchard

Cyprinus carpio – Common Carp

Pimephales promelas - Bluntnose Minnow

Carassius auratus- Goldfish

Anguilla anguilla- European Eel

Gadus morhua- Atlantic Cod

Order Clupeiformes

Order Cypriniformes

Order Anguilliformes

Order Gadiformes

Caesioperca lepidoptera- Butterfly Perch

Order Perciformes

TETRAPODS• terrestrial or aquatic vertebrates

• limbs as locomotory appendages

• lungs as respiratory organs

• vertebral column terminating in a tail (sometimes absent)

• heart with 2 atria and

Class Amphibia

• cold-blooded aquatic or

terrestrial vertebrates

• naked or with bony dermal

scales


• anamniote tetrapods

• Subclass Labyrinthodontia- earliest tetrapods

• with an armor of small, mostly, ventral scales,

and primitive vertebrae

• e.g. Eryops

• Order Ichthyostegalia

• e.g. Ichthyostega

• Order Temnospondyli

• e.g. Archegosaurus

• Order Anthracosauria

• e.g. Seymouria

Eryops megacephalus

Ichthyostega sp..

Archegosaurus decheni

Seymouria sanjuanensis

Class Amphibia

• cold-blooded aquatic or terrestrial

vertebrates


scales



• Subclass Lissamphibia- modern amphibians

• Order Proanura

• Order Anura- frogs and toads

• naked tailess amphibians

• without external gills

• two pairs of limbs; two occipital condyles

• e.g. Discoglossus, Pipa, Rana, Hyla, Xenopus, Bufo

• Order Urodela- newts and salamanders

• naked, tailed amphibians

• with or without external gills

• two pairs of limbs

• two occipital condyles

• e.g. Siren, Triton, Necturus, Salamandra, Ambystoma,

Plethodon, Cryptobranchus, Amphiuma

Order Proanura

Bufo bufo- Common Toad

Rana pipiens- Northern Leopard Frog

Hyla arborea

European Tree Frog

Xenopus laevis

African Clawed Frog

Discoglossus galganoi

Iberian Painted Frog

Pipa pipa- Star-fingered Toad

Siren sp.Triturus sp.

Necturus maculosus

Common Mudpuppy

Salamandra corsica

Corsican fire salamander

Ambystoma maculatum

Spotted Salamander

Plethodon cinereus- Redback Salamander

Cryptobranchus alleganiensis

Hellbender

Amphiuma means- two-toed amphiuma

Class Amphibia

• cold-blooded aquatic or terrestrial

vertebrates


scales



• Order Apoda- coecilians or blind worms

• vermiform amphibians

• without limbs or limb girdles

• vertebrae amphicoelous

• persistent notochord

Dermophis mexicanus- Mexican burrowing

caecilian

Class Reptilia

• Subclass Anapsida- no temporal fossae

• Order Captorhinida- Stem Reptiles

• Order Chelonia- turtles

• trunk short and broad

• inclosed in an armor (outer: horny; inner: bony

plates)

• limb girdles in horny shields

• e.g. Chelydra, Testudo, Emys, Chrysemys, Trionyx,

Thalassochelys, Chelone

• cold-blooded

• aquatic or terrestrial tetrapods

• naked, scaly or bony plates

• lungs as respiratory organ

• skeleton ossified with vertebrae

• one occipital condyle

• heart with sinus venosus; ventricle with

partition

Chelydra serpentine

Common Snapping Turtle

Testudo marginata

Marginated Tortoise

Emys orbicularis

European Pond Turtle

Chrysemys picta

Painted Turtle

Trionyx triunguis

African Softshell Turtle

Caretta caretta

Longgerhead Sea Turtle

Chelonia mydas

Green Sea Turtle

Class Reptilia

• Subclass Lepidosauria- two temporal fossae

• Order Rhynchocephalia

• long tailed lizardlike reptiles

• weak limbs

• teeth fused to jaw

• e.g. Sphenodon

• Order Squamata- lizards and snakes

• long tailed reptiles with horny scales

• teeth set in sockets

• Suborder Lacertilia- limbs present

• Suborder Ophidia- limbs absent

• cold-blooded







partition

Sphenodon punctatus

Northern Tuatara

Lampropeltis triangulum syspila

Milksnake

Pogona vitticeps

Central Bearded Dragon

Class Reptilia

• Subclass Euryapsida- one temporal fossa

• Order Sauropterygia

• e.g. Plesiosaurus

• Order Ichthyopterygia- aquatic fishlike reptiles

• cold-blooded







partition

Plesiosaurus

Ichthyosaurus communis

Class Reptilia

• Subclass Archosauria

• skull diapsid with two temporal openings

• birds stem from this subclass

• Order Thecodontia- stem archosaurs

• Order Pterosauria- winged reptiles

• e.g. Pterodactyl

• Order Saurischia- dinosaurs w/ reptile-like pelvis

• Order Ornithischia- dinosaurs w/ birdlike pelvis

• Order Crocodilia- crocodiles

• amphibious reptiles w/ bony plates underneath horny skin

• heart with two ventricles

• e.g. Alligator, Caiman, Crocodilus

• cold-blooded







partition

Pterodactylus sp.

Pterodactyl

Order Thecodontia

Karamuru vorax

Order Saurischia

Eoraptor lunensis- Raptor

Order Ornithischia

Stegosaurus

Alligator mississippiensis

American AlligatorCaiman yacare

Yacare Caiman

Crocodylus johnsoni

Freshwater Crocodile

Class Reptilia

• Subclass Synapsida- independently evolved one temporal fossa

• Order Pelycosauria

• Order Therapsida- lead to mammals

• cold-blooded







partition

Class Aves

• Subclass Archaeornithes- earliest known birds

• e.g. Protoavis, Archaeopteryx

• Subclass Neornithes- all the other birds

• Superorder Odontognathae- toothed Cretaceous

marine birds

• e.g. Hesperornis, Ichthyornis

• Superorder Palaeognathae- ratites

• e.g. ostrich, emu, rhea, cassowary

• Superorder Neognathae- Carinates

• warm-blooded

• oviparous (egg laying)

• feathers


• forelimbs modified to wings

• heart with two ventricles

• embryo with membranes

Archaeopteryx lithographica

Protoavis

Subclass Archaeornithes

Ichthyornis dispar

Hesperornis regalis

Superorder Odontognathae

Struthio camelus

Common OstrichDromaius novaehollandiae

Emu

Casuarius casuarius

Southern Cassowary

Rhea Americana

Greater Rhea

Superorder Neognathae

• Order Columbiformes

• e.g. doves, pigeons

• Order Pelecaniformes

• e.g. pelicans, cormorants

• Order Anseriformes

• e.g. ducks, geese, other waterfowl

• Order Galliformes

• e.g. quail, peacock, domestic fowl

• Order Falconiformes

• e.g. hawks, eagles, vultures

• Order Psittaciformes

• e.g. parrots, paroquets

• Order Passeriformes

• e.g. perching birds, song birds

• Carinates

Columba livia domestica

Feral Pigeon

Microcarbo melanoleucos

Little Pied Cormorant

Aix galericulata

Mandarin Duck

Pavo cristatusIndian Peafowl

Gyps fulvus

Griffon Vulture

Ara ararauna

Blue-and-yellow Macaw

Eopsaltria australis

Eastern Yellow Robin

Class Mammalia

• Subclass Prototheria- oviparous mammals

• Order Monotremata

• e.g. platypuses and echidna

• warm-blooded

• viviparous aquatic or terrestrial tetrapods

• hair as covering

• heart with 2 atria and 2 ventricles

• young nourished by milk

• embryo with membrane

Ornithorhynchus anatinus

Platypus

Zaglossus bruijni

Western Long-beaked

Echidna

Class Mammalia

• Subclass Theria

• Infraclass Metatheria- viviparous mammals with

abdominal skin pouch

• Order Marsupialia- Marsupials

• e.g. kangaroo, wallaby, wombats, opossums

• warm-blooded

• viviparous aquatic or terrestrial tetrapods

• hair as covering

• heart with 2 atria and 2 ventricles

• young nourished by milk

• embryo with membrane

Macropus giganteus

Eastern Grey Kangaroo

Vombatus ursinus

Common Wombat

Subclass Theria

• Infraclass Eutheria- true (chorioallantoic) placenta

• Order Insectivora- insectivores

• plantigrade clawed feet; elongated snout

• e.g. shrew, mole, hedgehog

• Order Xenarthra- edentates

• arboreal; teeth w/o enamel

• e.g. armadillo, sloths, South American anteaters

• Order Tubulidentata- long snout and tongue; ant-eating

• e.g. aardvark, African anteater

• Order Pholidota- ant-eating mammals

• head, body, and tail covered w/ imbricated horny scales

• e.g. pangolins (scaly anteaters)

• Order Chiroptera- flying mammals

• e.g. bats

• Order Primata

Blarina brevicauda

Northern Short-tailed ShrewManis javanica

Sunda PangolinDasypus novemcinctus

Nine-banded Armadillo

Bradypus variegatus

Brown-throated Sloth

Orycteropus afer

Aardvark

Corynorhinus townsendii

Townsend’s Big-eared Bat

Order Primata

• Suborder Prosimii

• e.g. lemur, lori, tarsier

• Suborder Anthropoidea

• Infraorder Platyrrhini- nostrils open to the sides

• e.g. new world monkeys and marmosets

• Infraorder Catarrhini- nostrils open downwards

• Superfamily Cercopithecoidea

• e.g. old world monkeys

• Superfamily Hominoidea

• terrestrial or arboreal hairy mammals

• five digits in each foot

• forefeet

• brain highly convoluted with very large

cerebral hemispheres

• e.g. lemurs, apes, humans

Carlito syrichta

Philippine Tarsier

Papio anubis

Olive Baboon

Old World Monkey

Mico melanurus

Black-tailed Marmoset

Ateles hybridus

Brown Spider Monkey

New World Monkey

Order Primata• Superfamily Hominoidea

• Family Hylobatidae

• e.g. gibbon

• Family Pongidae

• e.g. apes, orangutans, chimps, gorilla

• Family Hominidae

• e.g. Australopithecus, Homo erectus, Homo sapiens

• terrestrial or arboreal hairy mammals

• five digits in each foot

• forefeet

• brain highly convoluted with very

large cerebral hemispheres

• e.g. lemurs, apes, humans

Gorilla gorilla

Western Gorilla

Hylobates lar

Lar GibbonPongo pygmaeus

Bornean Orangutan

Australopithecus afarensis

Homo erectus

Subclass Theria

• Order Lagomorpha

• large external ears; four upper incisors

• e.g. rabbit, pika, hare

• Order Rodentia

• one pair of upper incisors; lacks canines; diastema

• Suborder Sciuromorpha

• Infraorder Sciuromorpha

• e.g. squirrel, marmot, prairie dog

• Infraorder Castorimorpha

• e.g. beavers

• Infraorder Myomorpha

• e.g. gophers, rats

• Suborder Hystricognathi

• Infraorder Caviomorpha

• e.g. porcupines, cavies, nutria

Infraclass Eutheria

Ochotona princeps

American Pika

Marmota flaviventris

Yellow-bellied Marmot

Castor canadensis

North American Beaver

Dolichotis sp.

Mara

Thomomys bottae

Botta's pocket gopher

Subclass Theria

• Order Carnivora- terrestrial carnivores

• canine teeth prominent

• e.g. canines, hyena, bear

• Order Pinnipedia- aquatic carnivores

• webbed feet modified to flippers

• Family Phocidae- earless (wriggling) seals

• Family Otariidae- eared (fur) seals and sea lions

• Family Odobenidae- walrus

• Order Perissodactyla- ungulates with mesaxonicfoot (Odd number of toes)

• herbivarous

• e.g. horse, rhinoceros, tapir

Infraclass Eutheria

Crocuta crocuta

Spotted Hyena

Tapirus indicus

Malayan Tapir

Diceros bicornis

Black Rhinoceros

Odobenus rosmarus

Walrus

Phoca vitulina

Harbor Seal

Neophoca cinerea

Austrailian Sea LionUrsus arctos

Brown Bear

Subclass Theria

• Order Artiodactyla- ungulates with paraxonic foot (even numbered toes)

• Suborder Suiformes

• simple stomach; dentition complete

• e.g. pig, hippo, peccaries

• Suborder Tylopoda

• upper incisor retained; semi-complex stomach

• e.g. camel, llama

• Suborder Ruminantia- cud chewers w/ complex stomach

• Family Cervidae- deer, caribou

• Family Giraffidae- giraffe

• Family Antilocapridae- pronghorn antelope

• Family Bovidae- ox, sheep, goat, true antelope

• Family Tragulidae- chevrotains (mouse deer)

Infraclass Eutheria

Tragulus nigricans

Philippine Mouse Deer

Giraffa Camelopardalis

Giraffe

Ovis aries

Domesticated Sheep

Pecari tajacu

Collared Peccary

Rangifer tarandus granti

Porcupine CaribouAntilocapra americana

Pronghorn

Lama glama

Domesticated Llama

Subclass Theria

• Order Hyracoidea- coneys

• short-tailed herbivorous mammals; no clavicles

• e.g. Hyraxes

• Order Proboscidea- tusked animals

• e.g. elephant, mastodon

• Order Sirenia- sea cows

• e.g. manatee, dugong

• Order Cetacea- fish-like aquatic mammals

• e.g. whales, dolphin, porpoise

Infraclass Eutheria

Heterohyrax brucei

Yellow-spotted Hyrax

Mammut sp.

Phocoena phocoena

Harbor Porpoise

Tursiops aduncus

Indo-pacific Bottlenose

Dolphin

Loxodonta Africana

African Bush Elephant

Dugong dugon

Dugong

Trichechus manatus

West Indian Manatee

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Taxonomy of Vertebrates