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Plants & CreaturesGreekEnglish

Eutherian

/juːˈθɪəriən/adjective

Belonging to the group of mammals whose young develop in the uterus nourished by a placenta.

The Greek roots

εὖ
well, true
+
θηρίον
thēríon
wild beast

Literally: true beast

The story of the word

Coined by Thomas Huxley in 1880 to separate placental mammals from marsupials and the egg-laying monotremes. The eu- is doing quiet nineteenth-century work, implying that placental mammals are the proper kind. Thērion also lies under theriac, the ancient antidote against animal venom, which slowly became treacle.

How it travelled
Ancient Greek → scientific coinage → English
First recorded
19th century

Same family

metatheriantherapsidtreacleeuphoria

In a sentence

Every eutherian from a shrew to a blue whale shares the same placental plan.

Australia's isolation left marsupials in niches eutherians fill elsewhere.

Built on the same root

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