• WordNet 3.6
    • n Prototheria echidnas; platypus
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Webster's Revised Unabridged Dictionary
    • n. pl Prototheria (Zoöl) Same as Monotremata.
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Century Dictionary and Cyclopedia
    • Prototheria A name proposed by Gill in 1872 for one of the major groups of the Mammalia, consisting of the Monotremata alone, as distinguished from the Eutheria: coextensive with Ornithodelphia.
    • Prototheria Those unknown primitive mammals which are the hypothetical ancestors of the monotremes: synonymous with Promammalia.
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Chambers's Twentieth Century Dictionary
    • Prototheria prō-tō-thē′ri-a the hypothetical primitive mammals, ancestors of the monotremes.
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Webster's Revised Unabridged Dictionary
NL., from Gr. prw^tos first + qhri`on, dim. of qh`r beast
Chambers's Twentieth Century Dictionary
Gr. prōtos, first, thēr, wild beast.


In literature:

These two divisions are (1) Prototheria and (2) Eutheria.
"The Cambridge Natural History, Vol X., Mammalia" by Frank Evers Beddard
These two genera are grouped under the name of Prototheria or Primitive Mammals.
"Stories of the Universe: Animal Life" by B. Lindsay