What does cenozoic mean?
Cenozoic is a geological term designating the most recent of Earth's major eras, the one we are still living in today. It began about 66 million years ago, immediately after the mass extinction that ended the dinosaurs, and is defined by the diversification and dominance of mammals, birds, and flowering plants. Scientists subdivide the Cenozoic into periods such as the Paleogene, Neogene, and Quaternary, and informally call it the Age of Mammals. The word functions chiefly as an adjective, as in 'Cenozoic fossils,' but it can also serve as a noun referring to the era itself, as in 'the Cenozoic began.' Because it carries the Greek roots for 'new' and 'life,' the name literally signals a fresh chapter in life's history. It appears mainly in scientific, educational, and documentary contexts rather than everyday conversation.
Of or relating to the most recent geological era, beginning about 66 million years ago and extending to the present, characterized by the ascendancy of mammals, birds, and flowering plants.
"Cenozoic sediment layers contain abundant mammalian fossils."
Usually capitalized when denoting the specific geological era.
The Cenozoic era itself; the span of geological time from roughly 66 million years ago to the present day.
"The Cenozoic saw the rise of whales, primates, and grasses."
Typically used with 'the,' as in 'the Cenozoic.'
We are living in the Cenozoic right now — the 'age of new life' that began the moment an asteroid wiped out the dinosaurs.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cenozoic
The word Cenozoic derives from Greek roots: kainos, meaning 'new' or 'recent,' and zōē, meaning 'life.' Coined in the 19th century by geologists classifying Earth's history, it was intended to mark the era of newly evolved forms of life that followed the age of reptiles. It belongs to a family of parallel terms built on the same '-zoic' element, including Paleozoic ('ancient life') and Mesozoic ('middle life'), which together structure the standard division of the Phanerozoic eon.
Related word forms
How cenozoic is actually used
A technical term used chiefly in geology, paleontology, and earth-science writing. It is normally capitalized when referring to the specific era. The informal phrase 'Age of Mammals' is often used as a popular gloss for the era.
Easily confused with cenozoic
The Mesozoic is the preceding era (roughly 252–66 million years ago), the age of the dinosaurs, whereas the Cenozoic is the current era that followed it.
The Paleozoic is the oldest of the three Phanerozoic eras (roughly 541–252 million years ago), long before the Cenozoic began.