Comanchean en · PROPN
Etymology
From Comanche (“a city in Texas”) + -ean.
Meanings
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A period of the Mesozoic era, between the Jurassic and the Upper Cretaceous periods, lasting from 145–100.5 millions of years ago.
There is a very general unconformity and break between the Lower and Upper Cretaceous; this has led Chamberlin and Salisbury to suggest that the Lower Cretaceous should be regarded as a separate period with the title "Comanchean."
[1911, “Cretaceous System”, in Encyclopædia Britannica, 11th edition, volume 7, New York, N.Y.: Encyclopædia Britannica, Inc., page 415: