The marsupials
A distinct group of mammals
Keep their young in pouch.
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They all give birth to
Underdeveloped offspring
Complete growth in pouch.
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The marsupium
Protects the developing
Young. Australian..
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North America
Not only Australian
Metatherians.
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History began
In the Northern Hemisphere
One hundred mil years.
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Share basic traits like
The hair and milk production
Metatherians.
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Have unique features
Unlike placental mammals
Have short gestation.
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Their reproduction
'Joey' born, embryonic
State. Must crawl to pouch.
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Embryonic state
Must crawl and attach to teat
Drinking milk for months.
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Different brain form
Lack a corpus collosum
Connecting fibers.
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Two brain hemispheres
Separate. No nerve fibers
As in placentals.
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Their anatomy
Females have two uteri
And two vaginas.
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To match vaginas
Males often have forked penis
It's bifurcated.
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Onefifty mil years
Metatherians diverged
From the placentals.
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Diverged Jurassic
Or Early Cretaceous
From the placentals.
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Earliest fossils
As i a / America
Not Australia.
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Sixtysix mil years
North to South America
There: diversity.
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South America
Major place: diversity
Marsupials , thrived.
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Then Antarctica
Warm, joined to Australia
Formed with Gondwana.
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In Australia
Filled all ecological
Niches--tree to hole.
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