They lived in the early Eocene, around 53 million years ago.

This species lived around 49 million years ago during the Early Eocene.

Anthrasimias is believed to have lived about 55 million years ago, during the early Eocene.

The site is late Palaeocene and early Eocene 50 to 60 million years ago.

The first members of the superfamily appeared during the Early Eocene 55 million years ago.

Ambulocetus natans lived from the early Eocene (50 to 48 million years ago).

Fossils have been found from England that date back to the early Eocene.

During the early Eocene, methane was another greenhouse gas that had a drastic effect on the climate.

Fossils of constellationfishes are known since the Early Eocene, more than 40 million years ago.

The age of Murgon fossils was determined as the early Eocene.