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promammal

noun pro·mammal \ (ˈ)prō+ \

Definition of promammal

1 :an extinct reptile exhibiting definite mammalian characteristics; especially :a synapsid reptile
2 a :a primitive mammal (as a platypus) not exhibiting all the characteristics of the group
b :one of the Protomammalia

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Origin and Etymology of promammal

1pro- + mammal

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