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*extant members that diverged in the ‘early cretaceous’ – or perhaps the ‘late jurassic’ – and which includes all ‘mammals’ more closely related to ‘marsupials’ than to ‘placentals’*
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(first proposed by Thomas Henry Huxley in 1880, it is a slightly more inclusive group than the marsupials; it contains all of the living mammals with abdominal pouches (most female marsupials) as well as their more primitive ancestors and relatives)
(‘metatherians’ are one of three main classes of extant mammals:
monotremes (egg laying mammals like the platypus and the echidna),
metatheria (or marsupials,
which includes the three American orders (
Didelphimorphia,
Paucituberculata
and Microbiotheria)
and the four Australasian orders (
Notoryctemorphia,
Dasyuromorphia,
Peramelemorphia
and Diprotodontia)),
and the eutherians (or placental mammals) consisting of twenty one orders, divided into 4 ‘superorders’)
Metatherians belong to a subgroup of the northern tribosphenic mammal clade or Boreosphenida.
They differ from all other mammals in certain morphologies like their dental formula, which includes about five upper and four lower incisors, a canine, three premolars, and four molars.
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(other morphologies include skeletal and anterior dentition, such as wrist and ankle apomorphies)
(all metatherians share derived pedal characters and calcaneal features)
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*👨🔬🕵️♀️🙇♀️*SKETCHES*🙇♂️👩🔬🕵️♂️*
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💕💝💖💓🖤💙🖤💙🖤💙🖤❤️💚💛🧡❣️💞💔💘❣️🧡💛💚❤️🖤💜🖤💙🖤💙🖤💗💖💝💘
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*🌈✨ *TABLE OF CONTENTS* ✨🌷*
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🔥🔥🔥🔥🔥🔥🔥*we won the war* 🔥🔥🔥🔥🔥🔥🔥