Definition of therian in English:

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Pronunciation: /ˈθɪərɪən/


A mammal of the major group Theria, which comprises the marsupials and placentals.
Example sentences
  • The reproductive system of the therians (marsupial and placental mammals) is a complex variation on the egg-layer's basic tubular structure.
  • First, we point out that the loss of tooth replacement in marsupials is neither unusual among therian mammals nor highly correlated with the extended period of nipple attachment in any obvious manner.
  • Fossils of therian mammals, which include the marsupials as well as the eutherians, may be recognized and distinguished by the number, morphology, and replacement pattern of their teeth.


Relating to or denoting therians.
Example sentences
  • Thus, relative to the primitive therian condition, marsupials have a distinctive, derived pattern of reduced dental replacement.
  • The physiological site of the defect in these mice, the chorionic placenta, is found only in therian mammals.
  • Unfortunately, molar nomenclature was developed for therian mammals, and some of the terminology turns out not to work very well at this fundamental level.

For editors and proofreaders

Line breaks: ther|ian

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