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Prototheria

plural noun
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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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History and Etymology for Prototheria

New Latin, from prot- + -theria

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“Prototheria.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/dictionary/Prototheria. Accessed 10 December 2019.

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