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Prototheria
plural noun
Pro·to·the·ria
Definition of Prototheria
: a subclass of Mammalia that is coextensive with Monotremata or in some classifications includes both Monotremata and Allotheria and that is represented in the recent fauna solely by the egg-laying platypus and echidnas
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Origin and Etymology of prototheria
New Latin, from prot- + -theria
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