Prototherian

//ˌpɹoʊtɵˈθɪəɹi.ən// adj, noun

adj, noun ·Rare ·Advanced level

Definitions

Noun
  1. 1
    Any of the egg-laying mammals of the subclass Prototheria; a monotreme.

    "Monotremes (prototherians), which include the duck-billed platypus, and short- and long-beaked echidnas, have a cloaca—a single opening for the fecal, urinary, and reproductive tracts."

  2. 2
    primitive oviparous mammals found only in Australia and Tasmania and New Guinea wordnet
Adjective
  1. 1
    Belonging or pertaining to the subclass Prototheria.

    "It is evident that the Edentates are widely separated from all other existing Eutherians; and Professor W. K. Parker, in view of the tendency to a variation in the number of cervical vertebræ and other features, has suggested a separate origin from a Prototherian stock."

Example

More examples

"It is evident that the Edentates are widely separated from all other existing Eutherians; and Professor W. K. Parker, in view of the tendency to a variation in the number of cervical vertebræ and other features, has suggested a separate origin from a Prototherian stock."

Etymology

From translingual Prototheria + -an, from Ancient Greek πρωτο- (prōto-, “proto-, first”) + θηρίον (thēríon, “beast”).

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.