MidDevonian

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Mid-Devonian
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A Living Fossil the coelacanth
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Crossopterygian fin
Early tetrapod limb
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Actinopterygian fin
Primitive tetrapod limb
Crossopterygian fin
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Eusthenopteron
(osteolepiform)
Shallow-water predator
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Panderichthyes (osteolepiform)
Lost anal dorsal fins Eyes on top of head
dorsoventral flattening (shallower
water) Pectoral girdle still attached to
skull Fish-like fins could not walk on them
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Tiktaalik
Scales on the back Broad, flat head with dorsal
eyes Pectoral girdle free from head (neck) Fins
could orient downward to support weight could
walk
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Ichthyostega
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Ichthyostega
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Acanthostega skeleton
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Acanthostega reconstruction
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Acanthostega habitat
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Ichthyostega foot bones
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Ichthyostega hindlimb
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labyrinthodont tooth present in rhipidistian
crossopterygians, labyrinthodont amphibians
and stem reptiles
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stereospondyl
rhachitome
Order Temnospondyli
Order Anthracosauria
Seymouriamorpha
Embolomeri
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Suborder Seymouriamorpha - gephyrostega
Suborder Diadectomorpha
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Fam. Proteidae
Fam. Cryptobranchidae
Fam. Salamandridae
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Fam. Ambystomatidae
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Fam. Plethodontidae
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Order Gymnophiona - caecilians
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short trunk
elongated ilium
femur
urostyle (fused caudal vertebrae)
tibiofibula (fused tibia fibula
elongated proximal tarsals
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Desert frog emerging from estivation