An Anomaly to the Eocene opened up in Ancient Egypt. The Egyptians, believing it to be a piece of the Sun, contained it in a cage made of magnetite, the Sun Cage. A Pristichampsus came through the Anomaly and the Egyptians based the demon Ammut on it.
In the 21st century, when the Sun Cage was kept at the British Museum the Anomaly reopened and the Pristichampsus came through again. The Pristichampsus ultimately returned through the Anomaly before it closed.
An Anomaly to the Eocene opened near a campsite circa 2009, and a herd of Embolotherium came through. Some of the Embolotherium were returned through the Anomaly, while the rest were marooned in the Present when the Anomaly closed. Helen Cutter used the Anomaly Opening Device to send the Embolotherium through another Anomaly to another time period.
The Eocene epoch lasted from 56 to around 34 million years ago. During the Eocene, mammals became dominant, while the giant birds of before went into decline (though they continued to exist in South America). During the early Eocene, most of Earth was covered by forests. The dominant predators were huge carnivorous birds and crocodilians. Mammals were not very big, only about the size of cats. In the later parts of the Eocene the mammals began to take over and grew large enough to overthrow the birds. Creatures of the Eocene include Pristichampsus and Embolotherium.