Part 1
Where does it start?
Early Chordates, Craniate and
vertebrate origins
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)
Phylum Chordata
Teleostomi (bony fishes + tetrapods)
Tetrapoda (four-limbed vertebrates)
Amniota (tetrapods with embryos having
extraembryonic membranes)
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Osteichthyes
(bony fishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Crocodilia
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin in epidermis
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Lung or swimbladder derived from gut, bony endoskeleton
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Neural crest
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
Pikaia – a very early (fossil) chordate
Phylum Echinodermata
Phylum Chordata
- Origins
Phylum Hemichordata
Carpoids
Fossil echinoderms
…..a link between nonchordates and chordates?
Deuterostomia
Chaetognatha
Xenoturbellida
Echinodermata
Ambulacraria
Hemichordata
Enteropneusta
Xenoturbella
Chordata
Pterobranchia
Loss of gill slits
Pentaradiality
Hooded circlet
of spines
around mouth
Buccal diverticulum
Mesocoelomic
ducts
Endoskeleton of
stereom ossicles
Coelom tripartite
Postanal tail
Notochord
Endostyle or
thyroid gland
Axial complex
Unique larval
morphology
Diffuse nervous system
Unusual ciliary structure
Mouth not derived from blastopore
Enterocoely
Gill slits in pharynx
Radial 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 having
extraembryonic membranes)
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Osteichthyes
(bony fishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Crocodilia
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin in epidermis
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Lung or swimbladder derived from gut, bony endoskeleton
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Neural crest
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
5 traits define all
chordates
Protochordata
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Agnatha
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Suckerlike oral
disc, long larval
stage, 7 pairs
of gills
Slime glands,
accessory
hearts
Neural crest
5 traits define
all chordates
*notochord
*dorsal hollow nerve cord
*pharyngeal slits
*postanal tail
*endostyle
Chordate Traits
Endostyle
Adaptive significance
Gill arches
Vertebral Column
Complex central Nervous
system
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)
Phylum Chordata
Teleostomi (bony fishes + tetrapods)
Tetrapoda (four-limbed vertebrates)
Amniota (tetrapods with embryos having
extraembryonic membranes)
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Osteichthyes
(bony fishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Crocodilia
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin in epidermis
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Lung or swimbladder derived from gut, bony endoskeleton
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Neural crest
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
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)
“Protochordates”
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Amniota (tetrapods with embryos having
extraembryonic membranes)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Osteichthyes
(bony fishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Crocodilia
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin in epidermis
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Lung or swimbladder derived from gut, bony endoskeleton
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Neural crest
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
Chordata (animals with notochord at some stage in life cycle)
Craniata (euchordates with a cranium)
Gnathostomata (Craniata with jaws)
Teleostomi (bony fishes + tetrapods)
Craniates
Tetrapoda (four-limbed vertebrates)
Amniota (tetrapods with embryos having
extraembryonic membranes)
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Osteichthyes
(bony fishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin in epidermis
Lung or swimbladder derived from gut, bony endoskeleton
Neural crest
Crocodilia
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)
Vertebrates
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Osteichthyes
(bony fishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Mammalia
(mammals)
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin in epidermis
Lung or swimbladder derived from gut, bony endoskeleton
Neural crest
Crocodilia
Chordata (animals with notochord at some stage in life cycle)
Craniata (euchordates with a cranium) = Vertebrata
Gnathostomata (Craniata with jaws)
“Fishes”
Teleostomi (bony fishes + tetrapods)
Tetrapoda (four-limbed vertebrates)
Amniota (tetrapods with embryos having
extraembryonic membranes)
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Osteichthyes
(bony fishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin in epidermis
Lung or swimbladder derived from gut, bony endoskeleton
Neural crest
Crocodilia
Chordata (animals with notochord at some stage in life cycle)
Craniata (euchordates with a cranium) = Vertebrata
Gnathostomata (Craniata with jaws)
Teleostomi (bony fishes + tetrapods)
“Fishes”: 6 distinct lineages
Tetrapoda (four-limbed vertebrates)
Amniota (tetrapods with embryos having
extraembryonic membranes)
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Osteichthyes
(bony fishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin in epidermis
Lung or swimbladder derived from gut, bony endoskeleton
Neural crest
Crocodilia
Chordata (animals with notochord at some stage in life cycle)
Craniata (euchordates with a cranium) = Vertebrata
Gnathostomata (Craniata with jaws)
Tetrapods
Teleostomi (bony fishes + tetrapods)
Tetrapoda (four-limbed vertebrates)
Amniota (tetrapods with embryos having
extraembryonic membranes)
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Osteichthyes
(bony fishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin in epidermis
Lung or swimbladder derived from gut, bony endoskeleton
Neural crest
Crocodilia
Chordata (animals with notochord at some stage in life cycle)
Craniata (euchordates with a cranium) = Vertebrata
Gnathostomata (Craniata with jaws)
Teleostomi (bony fishes + tetrapods)
Amphibians
Tetrapoda (four-limbed vertebrates)
Amniota (tetrapods with embryos having
extraembryonic membranes)
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Osteichthyes
(bony fishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin in epidermis
Lung or swimbladder derived from gut, bony endoskeleton
Neural crest
Crocodilia
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)
Protochordata
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Osteichthyes
(bony fishes)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Amniotes
Agnatha
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin in epidermis
Lung or swimbladder derived from gut, bony endoskeleton
Neural crest
Crocodilia
Chordata (animals with notochord at some stage in life cycle)
Craniata (euchordates with a cranium) = Vertebrata
Gnathostomata (Craniata with jaws)
Mammals
Teleostomi (bony fishes + tetrapods)
(Synapsida)
Tetrapoda (four-limbed vertebrates)
Amniota (tetrapods with embryos having
extraembryonic membranes)
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Osteichthyes
(bony fishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin in epidermis
Lung or swimbladder derived from gut, bony endoskeleton
Neural crest
Crocodilia
Chordata (animals with notochord at some stage in life cycle)
Craniata (euchordates with a cranium) = Vertebrata
Gnathostomata (Craniata with jaws)
Diapsida
Teleostomi (bony fishes + tetrapods)
Tetrapoda (four-limbed vertebrates)
(“reptiles” + birds)
Amniota (tetrapods with embryos having
extraembryonic membranes)
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Osteichthyes
(bony fishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin n epidermis
Lung or swimbladder derived from gut, bony endoskeleton
Neural crest
Crocodilia
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)
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Osteichthyes
(bony fishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin in epidermis
Lung or swimbladder derived from gut, bony endoskeleton
Neural crest
Crocodilia
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)
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Reptilia
Osteichthyes
(bony fishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Lepidosauria Testudines
(lizards, snakes) (turtles)
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Crocodilia
Aves
(birds)
Skull with upper and
lower temporal fenestra,
Beta-keratin in epidermis
Egg with extraembryonic membranes
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Lung or swimbladder derived from gut, bony endoskeleton
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Neural crest
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
“Protochordates”
Not craniates – but the
same phylum
Subphylum Cephalochordata
lancetes,
amphioxus
nerve cord
perforated
pharynx
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)
Vertebrata
Teleostomi (bony fishes + tetrapods)
Protochordata
Agnatha
Urochordata
(tunicates)
Cephalochordata
(lancelets)
Osteichthyes
(bony fishes)
Petromyzontida
(lampreys)
Myxini
(hagfishes)
Actinopterygii
(ray-finned fishes)
Sarcopterygii
(lungfishes,
coelacanths)
Amphibia
Mammalia
(mammals)
Craniata
Hair,
mammary
glands
Chondrichthyes
(sharks, rays,
chimaeras)
Suckerlike oral
disc, long larval
stage, 7 pairs Heterocercal
of gills
caudal fin,
placoid scales,
Slime glands,
cartilaginous
accessory
skeleton
hearts
Paired limbs used for terrestrial locomotion
Unique supportive elements in skeleton or
girdles of appendages
Lung or swimbladder derived from gut, bony endoskeleton
Jaws, 3 pairs semicircular canals, paired appendages,
gill filaments lateral to gill support
2 pairs semicircular canals, vertebrae
Neural crest
Distinct head and tripartite brain, paired specialized sense organs, 1 pair
semicircular canals, glomerular kidney, ectodermal placodes
Notochord, dorsal hollow nerve cord, pharyngeal slits,
postanal tail, endostyle
Vertebrata
Craniata
Craniate innovations
Cranium
Craniate innovations
Tripartite brain
Forebrain
Midbrain
Hindbrain
Craniate innovations
Complex Cranial Sense organs
Olfaction
Vision
Hearing (otic)
Craniate innovations
Inner ear with at least one
semicircular canal
Craniate innovations ?
Unique embryonic tissues
neural crest cells
ectodermal placodes
Acraniate Chordate
Craniate
Very early
craniates
(probably)
†Myllokunmingia
† Haikouichthys
†others
Very early
craniates (probably)
†Myllokunmingia
† Haikouichthys
†others
Relationships under debate
†Myllokunmingia
† Haikouichthys
Most primitive (living) craniate
Hagfishes
Vertebrata
Craniata
Vertebrata
Vertebrates
Vertebrate innovations
Vertebrae
Vertebrate innovations
Inner ear with at least
two semicircular canals
Vertebrate innovations
All sorts of new
physiology
Most primitive
living vertebrate
Lampreys
Vertebrata
Vertebrates
Craniates
Craniates
Vertebrates