The Early Miocene (also known as Lower Miocene) is a sub-epoch of the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

Epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided b ...

made up of two stages: the Aquitanian and

Burdigalian The Burdigalian is, in the geologic timescale, an age (geology), age or stage (stratigraphy), stage in the early Miocene. It spans the time between 20.43 ± 0.05 annum, Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian (sta ...

stages. The sub-epoch lasted from 23.03 ± 0.05 Ma to 15.97 ± 0.05 Ma (million years ago). It was preceded by the

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

epoch. As the climate started to get cooler, the landscape started to change. New mammals evolved to replace the extinct animals of the Oligocene epoch. The first members of the

hyena Hyenas or hyaenas ( ; from Ancient Greek , ) are feliform carnivoran mammals belonging to the family Hyaenidae (). With just four extant species (each in its own genus), it is the fifth-smallest family in the order Carnivora and one of the sma ...

and

weasel Weasels are mammals of the genus ''Mustela'' of the family Mustelidae. The genus ''Mustela'' includes the least weasels, polecats, stoats, ferrets, and European mink. Members of this genus are small, active predators, with long and slend ...

family started to evolve to replace the extinct ''

Hyaenodon ''Hyaenodon'' ("hyena-tooth") is an Extinction (biology), extinct genus of Carnivore, carnivorous Placentalia, placental mammals from extinct tribe Hyaenodontini within extinct subfamily Hyaenodontinae (in extinct Family (biology), family Hyaenod ...

'', entelodonts and

bear-dogs Amphicyonidae is an extinct Family (biology), family of Terrestrial animal, terrestrial carnivorans belonging to the suborder Caniformia. They first appeared in North America in the middle Eocene (around 45 mya), spread to Europe by the late Eoce ...

. The chalicotheres survived the Oligocene epoch. A new genus of entelodont called '' Daeodon'' evolved in order to adapt to the new habitats and hunt the new prey animals of the Early Miocene epoch; it quickly became the top predator of

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. But it became extinct due to

competition Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indi ...

from '' Amphicyon'', a newcomer from

Eurasia Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...

. ''Amphicyon'' bested ''Daeodon'' because the bear-dog's larger brain, sharper teeth and longer legs built for longer chases helped it to overcome its prey.

References

External links

GeoWhen Database - Early Miocene
.01 Aquitanian (stage) Burdigalian 01 {{geochronology-stub