Mesozoic
/ˌmɛz.əˈzoʊ.ɪk/noun
The geological era from about 252 to 66 million years ago, including the Triassic, Jurassic, and Cretaceous periods.
Did you know?Mesozoic was coined in the 19th century from Greek roots meaning “middle” and “life,” because geologists saw it as the middle chapter of Earth’s living history.
Etymological Timeline
Ancient Greek
Greek
mésos
“middle”
Ancient Greek
Greek
zōḗ
“life”
19th Century
English
Mesozoic
“a geological era between older and younger rock layers, later formalized as the age of reptiles/dinosaurs”
Modern English
English
Mesozoic
“the era of Earth’s history spanning the Triassic, Jurassic, and Cretaceous periods”
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