Early Chordates, Craniate and vertebrate origins

Where does it start?Part 1

Phylum Chordata

Animal Kingdom Vertebrates over here

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)

Amniota (tetrapods with embryos havingextraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin in epidermis

Phylum Chordata

Pikaia – a very early (fossil) chordate

Phylum Hemichordata

Phylum Echinodermata

Phylum Chordata - Origins

Carpoids

…..a link between non-chordates and chordates?

Fossil echinoderms

DeuterostomiaAmbulacraria

Chaetognatha Xenoturbellida Echinodermata Hemichordata Chordata

Xenoturbella Enteropneusta Pterobranchia

Hooded circletof spinesaround mouth

Loss of gill slits

Pentaradiality

Endoskeleton ofstereom ossicles

Buccal diverticulumMesocoelomic

ducts

Postanal tail

Notochord

Endostyle orthyroid glandCoelom tripartite

Axial complex

Unique larvalmorphology

Diffuse nervous system

Unusual ciliary structure

Mouth not derived from blastoporeEnterocoelyGill slits in pharynxRadial determinate cleavage

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)

Amniota (tetrapods with embryos havingextraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin in epidermis

5 traits define all chordates

Protochordata Agnatha

Urochordata(tunicates)

Petromyzontida(lampreys)

Cephalochordata(lancelets)

Myxini(hagfishes)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gills

Neural crest

*notochord*dorsal hollow nerve cord*pharyngeal slits*postanal tail*endostyle

5 traits define all chordates

Endostyle

Chordate Traits

Gill archesVertebral ColumnComplex central Nervous

system

Adaptive significance

Pikaia – a very early (fossil) chordate

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)

Amniota (tetrapods with embryos havingextraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin in epidermis

Phylum Chordata

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)

Amniota (tetrapods with embryos havingextraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin in epidermis

“Protochordates”

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)

Amniota (tetrapods with embryos havingextraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin in epidermis

Craniates

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)

Amniota (tetrapods with embryos havingextraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin in epidermis

Vertebrates

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)

Amniota (tetrapods with embryos havingextraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin in epidermis

“Fishes”

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)

Amniota (tetrapods with embryos havingextraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin in epidermis

“Fishes”: 6 distinct lineages

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)Amniota (tetrapods with embryos having

extraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin in epidermis

Tetrapods

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)

Amniota (tetrapods with embryos havingextraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin in epidermis

Amphibians

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)Amniota (tetrapods with embryos having

extraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin in epidermis

Amniotes

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)

Amniota (tetrapods with embryos havingextraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin in epidermis

Mammals (Synapsida)

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)

Amniota (tetrapods with embryos havingextraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin n epidermis

Diapsida (“reptiles” + birds)

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)

Amniota (tetrapods with embryos havingextraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin in epidermis

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Tetrapoda (four-limbed vertebrates)

Amniota (tetrapods with embryos havingextraembryonic membranes)

ReptiliaProtochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Lepidosauria(lizards, snakes)

Testudines(turtles) Crocodilia

Aves(birds)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Egg with extraembryonic membranes

Skull with upper andlower temporal fenestra,Beta-keratin in epidermis

“Protochordates”

Not craniates – but the same phylum

Subphylum Cephalochordatalancetes, amphioxus

perforated pharynx

nerve cord notochord

endostyle post-anal tail

Subphylum Craniata

Subphylum Craniata

Chordata (animals with notochord at some stage in life cycle)

Craniata (euchordates with a cranium) = Vertebrata

Gnathostomata (Craniata with jaws)

Teleostomi (bony fishes + tetrapods)

Protochordata Agnatha Osteichthyes(bony fishes)

Urochordata(tunicates)

Petromyzontida(lampreys)

Actinopterygii(ray-finned fishes) Sarcopterygii

(lungfishes,coelacanths)

AmphibiaMammalia(mammals)

Cephalochordata(lancelets)

Myxini(hagfishes) Chondrichthyes

(sharks, rays,chimaeras)

Slime glands,accessory

hearts

Suckerlike oraldisc, long larvalstage, 7 pairs

of gillsHeterocercalcaudal fin,

placoid scales,cartilaginous

skeleton

Hair,mammary

glands

Notochord, dorsal hollow nerve cord, pharyngeal slits,postanal tail, endostyle

Neural crest

Distinct head and tripartite brain, paired specialized sense organs, 1 pairsemicircular canals, glomerular kidney, ectodermal placodes

2 pairs semicircular canals, vertebrae

Jaws, 3 pairs semicircular canals, paired appendages,gill filaments lateral to gill support

Lung or swimbladder derived from gut, bony endoskeleton

Unique supportive elements in skeleton orgirdles of appendages

Paired limbs used for terrestrial locomotion

Craniata

Vertebrata

Vertebrata

Craniata

CraniumCraniate innovations

Craniate innovations

Tripartite brainForebrainMidbrainHindbrain

Craniate innovations

Complex Cranial Sense organs

OlfactionVisionHearing (otic)

Craniate innovations

Inner ear with at least one semicircular canal

Unique embryonic tissues

Craniate innovations ?

neural crest cells

ectodermal placodes

Craniate

Acraniate Chordate

Very early craniates (probably)

†Myllokunmingia † Haikouichthys †others

†Myllokunmingia † Haikouichthys †others

Very early craniates (probably)

Relationships under debate

†Myllokunmingia † Haikouichthys

Most primitive (living) craniate

Hagfishes

Vertebrata

Craniata

Vertebrata

Vertebrates

Vertebrate innovations

Vertebrae

Inner ear with at least two semicircular canals

Vertebrate innovations

All sorts of new physiology

Vertebrate innovations

Most primitive living vertebrate

Lampreys

Vertebrata

Craniates

Vertebrates

Craniates

Vertebrates