Amniotes

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Amniotes
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Amniotes

• Named for amniotic membrane that surrounds
  development embryo
• Egg enclosed in shell and membranes
• for development of embryos on land

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Amniote animals

• Conventional classification
• Chordate classes
• reptiles
• birds
• mammals

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Amniote egg

• Embryo
• amnion- surrounds embryo- physical protection
• chorion- gas exchange under shell
• yolk sac- yolk phospho- lipoproteins
• allantois nitrogenous waste- ammonia

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Amnionic egg
chorion
embryo
amnion
Yolk sac
allantois
shell
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Temporal fenestra

• Orbit of eye
• Anapsida- no post-otic arches
• Synapsida a temporal fenestra
• zygomatic arch
• Diapsida ventral temporal fenestra
• dorsal temporal fenestra

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Amniotes -phylogeny
Synapsida
Mammals
Amniotes
Archosaurs
Diapsida
Squamata
Anapsida
Turtles