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Kingdom Animalia
Part III - Chordate Animals
(including the
Vertebrates)
Chordate characteristics
*
(somites)
*
SP:
Cephalochordata =
lancelets
tentacles
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SP: Urochordata = tunicates, sea squirts, salps, ascidians
Craniate
features
developmental genes now
make a brain
neural
crest tissue
Early chordate & craniate animals
Haikouella
early chordate
Myllokunmingia
early craniate
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Vertebrates: cyclostomes (jawless)
Cl: Myxini = hagfishes
Vertebrates: cyclostomes (jawless)
Cl: Petromyzontida = lampreys
Early jawless
vertebrates
conodonts
(armored)
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Gnathostomes = jawed
mouths
Hypothesis: jaw evolution
(remaining gill slits become
major sites of gas exchange)
Cl: Chondrichthyes =
cartilaginous fish
Spleen! Kidney!
Stomach! Testis! Gill slits!
Clasper!
Mouth!
(a)!
Pelvic! Cloaca!
fin!
Intestine!Pancreas!
Liver!
Heart! Pericardial!Pharynx!
cavity!
Fig. 30.13a!
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Clade Osteichthyes
Cl: Actinopterygii = ray-fin fishes
Garibaldi (CA state marine fish)
Clade
Osteichthyes
Cl: Actinistia = coelocanths
Cl:
Sarcopterygii
(lobed fin
fishes)
Cl: Dipnoi =
lungfishes
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Early Tetrapods
(many of these
added in the last 20
years)
tetrapod
fish
“fishapod”
Clade
Osteichthyes
Cl: Amphibia
Cl: Apoda = caecilians
Cl: Anura = frogs &
toads
Cl: Urodela =
newts &
salamanders
Clade Osteichthyes
Cl: Amniotes
new invention: amniotic egg with extraembryonic membranes
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Clade Osteichthyes
Cl: Amniotes
(therapsids)
Alternate hypothesis about turtles (closer to other extant reptiles)
Cl: Reptilia
tuatara
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Cl: Reptilia
Birds
Birds: adaptations for flight
Hollow bones
Feathers
Cl: Mammals
Cl: Monotremes
= egg-layers
spiny
echidna
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Cl: Mammals
Marsupials = pouched mammals
Convergent
evolution
Cl: Mammals
Eutherians =
placental mammals
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