Definition of Eocene in English:

Eocene

adjective

  • Relating to or denoting the second epoch of the Tertiary period, between the Palaeocene and Oligocene epochs.

    ‘similar patterns have been documented in North American mammals across the late Eocene extinction’
    • ‘It includes the Palaeocene, Eocene, and Oligocene epochs, spanning the time from the end of the Mesozoic to the beginning of the Neogene.’
    • ‘An early Cretaceous to late Eocene volcanic arc was located in the present-day Central Depression.’
    • ‘Western Ecuador consists of a complex tectonic melange of oceanic terranes accreted to the continental margin from Late Cretaceous to Eocene time.’
    • ‘This age is notable because it is precisely the age of the boundary between the Paleocene and Eocene epochs.’
    • ‘The La Meseta Formation is the best exposed and most fossiliferous rock unit of Eocene age in Antarctica.’

The Eocene epoch lasted from 56.5 to 35.4 million years ago. It was a time of rising temperatures, and there was an abundance of mammals, including the first horses, bats, and whales

noun

  • the EoceneThe second epoch of the Tertiary period, or the system of rocks deposited during it.

    ‘a very minor extinction occurred at the end of the middle Eocene’

The Eocene epoch lasted from 56.5 to 35.4 million years ago. It was a time of rising temperatures, and there was an abundance of mammals, including the first horses, bats, and whales

Origin

Mid 19th century from Greek ēōs ‘dawn’ + kainos ‘new’.

Pronunciation

Eocene

/ˈiːə(ʊ)siːn/