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