Geologic Time Scale: Eocene Epoch
(56 to 33.9 million years ago)
The Eocene is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name Eocene comes from the Ancient Greek meaning “dawn” and “new/recent” and refers to the “dawn” of modern (“new”) fauna that appeared during the epoch.
The Eocene is known for containing the warmest period during the Cenozoic, as well as the decline into an icehouse climate and rapid expansion of the Antartic ice sheet. The Eocene bears witness to the introduction of the first flying mammals-bats and marine mammals-whales. Many modern plant and bird orders first appear.
Priabonian Age/Stage
37.71 to 33.9 million years ago
The Priabonian Stage was named after the small hamlet of Priabona in the community of Monte di Malo, in the Veneto region of northern Italy by Albert de Lapparent and Ernst Munier-Chalmas in 1893.
North American Priabonian Stage 37.71 to 33.9 million years ago

Genus: Basilosaurus
Name meaning: King lizard
Synonym name: Zeuglodon
Classification: Family: Basilosauridae
Time: Late Eocene (Bartonian and Priabonian)
Range: United States, Egypt, Western Sahara, Morocco, Jordon,Tunisia, and Pakistan
Diet: Carnivore

Genus and species: Hyaenodon horridus
Name meaning: Hyena-tooth
Common name: Hyaenodon
Classification: Order: Hyaenodonta – Family: Hyaenodontidae
Time: Middle Eocene to Middle Miocene
Range: Eurasia, Africa, and North America
Diet: Carnivore

Genus: Megacerops “Large horned face”
Size: 2.5 meters tall at the shoulder
Locations: Canada, Seskatchewan. USA, Colorado, Montana, South Dakota, Wyoming
Time period: Eocene (Priabonian) to Oligocene (Rupelian)
Diet: Herbivore.
African and Middle Eastern Priabonian Stage 37.71 to 33.9 million years ago

Genus: Basilosaurus
Name meaning: King lizard
Synonym name: Zeuglodon
Classification: Family: Basilosauridae
Time: Late Eocene (Bartonian and Priabonian)
Range: United States, Egypt, Western Sahara, Morocco, Jordon,Tunisia, and Pakistan
Diet: Carnivore

Genus and species: Hyaenodon horridus
Name meaning: Hyena-tooth
Common name: Hyaenodon
Classification: Order: Hyaenodonta – Family: Hyaenodontidae
Time: Middle Eocene to Middle Miocene
Range: Eurasia, Africa, and North America
Diet: Carnivore

Genus: Arsinoitherium “Arsinoe’s beast, after Queen Arsinoe I of Ancient Egypt”
Time: Late Eocene to Early Oligocene 36-27 mya
Locations: Egypt - Jebel Qatrani Formation, Ethiopia, Oman - Aydim Formation, Saudi Arabia - Shumaysi Formation.
Size: 1.75m (5.7ft) hieght and 3m (9.8ft) length
Diet: Herbivore
Asian Priabonian Stage 37.71 to 33.9 million years ago

Genus and species: Hyaenodon horridus
Name meaning: Hyena-tooth
Common name: Hyaenodon
Classification: Order: Hyaenodonta – Family: Hyaenodontidae
Time: Middle Eocene to Middle Miocene
Range: Eurasia, Africa, and North America
Diet: Carnivore

Genus: Andrewsarchus (Andrew’s ruler)
Known locations: Mongolia
Time period: Eocene (Lutetian to Priabonian)
Size: Total size uncertain due to lack of remains. Skull is 83 centimeters long
Diet: Carnivore

Genus: Entelodon ”Perfect teeth”
Known locations: Eurasia
Time period: Bartonian of the Eocene through to Rupelian of the Oligocene
Size: Around 3 meters long
Diet: Omnivore?
European Priabonian Stage 37.71 to 33.9 million years ago

Genus and species: Hyaenodon horridus
Name meaning: Hyena-tooth
Common name: Hyaenodon
Classification: Order: Hyaenodonta – Family: Hyaenodontidae
Time: Middle Eocene to Middle Miocene
Range: Eurasia, Africa, and North America
Diet: Carnivore

Genus and species: Eusmilus bidentatus
Common name: False Saber-toothed cat
Classification: Family: Nimravidae – Subfamily: Hoplophoninae
Time: Late Eocene to Early Oligocene
Range: Europe
Diet: Carnivore

Genus: Entelodon ”Perfect teeth”
Known locations: Eurasia
Time period: Bartonian of the Eocene through to Rupelian of the Oligocene
Size: Around 3 meters long
Diet: Omnivore?

Genus: Palaeotherium ”Ancient beast”
Known locations: Europe, France, Germany, Spain, Switzerland and the United Kingdom.
Time period: Eocene (Lutetian to Priabonian) and Oligocene (Rupelian )
Size: 120 centimeters long, 75 to 140 centimeters high at the shoulder
Diet: Herbivore
Bartonian Age/Stage
41.2 to 37.71 million years ago
The Bartonian Stage was named after the coastal village Barton-on-Sea (part of New Milton) in southern England by Swiss stratigrapher Karl Mayer-Eymar in 1857.
North American Bartonian Stage 41.2 to 37.71 million years ago

Genus: Basilosaurus
Name meaning: King lizard
Synonym name: Zeuglodon
Classification: Family: Basilosauridae
Time: Late Eocene (Bartonian and Priabonian)
Range: United States, Egypt, Western Sahara, Morocco, Jordon,Tunisia, and Pakistan
Diet: Carnivore

Genus and species: Hyaenodon horridus
Name meaning: Hyena-tooth
Common name: Hyaenodon
Classification: Order: Hyaenodonta – Family: Hyaenodontidae
Time: Middle Eocene to Middle Miocene
Range: Eurasia, Africa, and North America
Diet: Carnivore

Genus: Uintatherium “Beast of the Uinta Mountains”
Classification: Family: Uinatatheriidae
Time: Eocene (Ypresian to Bartonian)
Location: China, Henan Province – Lushi Formation. USA – California, Texas, Utah, Wyoming.
Size: 1.70m (5.6 ft) Height
Diet: Herbivore
African and Middle Eastern Bartonian Stage 41.2 to 37.71 million years ago

Genus: Basilosaurus
Name meaning: King lizard
Synonym name: Zeuglodon
Classification: Family: Basilosauridae
Time: Late Eocene (Bartonian and Priabonian)
Range: United States, Egypt, Western Sahara, Morocco, Jordon,Tunisia, and Pakistan
Diet: Carnivore

Genus and species: Hyaenodon horridus
Name meaning: Hyena-tooth
Common name: Hyaenodon
Classification: Order: Hyaenodonta – Family: Hyaenodontidae
Time: Middle Eocene to Middle Miocene
Range: Eurasia, Africa, and North America
Diet: Carnivore
Asian Bartonian Stage 41.2 to 37.71 million years ago

Genus and species: Hyaenodon horridus
Name meaning: Hyena-tooth
Common name: Hyaenodon
Classification: Order: Hyaenodonta – Family: Hyaenodontidae
Time: Middle Eocene to Middle Miocene
Range: Eurasia, Africa, and North America
Diet: Carnivore

Genus: Andrewsarchus (Andrew’s ruler)
Known locations: Mongolia
Time period: Eocene (Lutetian to Priabonian)
Size: Total size uncertain due to lack of remains. Skull is 83 centimeters long
Diet: Carnivore

Genus: Entelodon ”Perfect teeth”
Known locations: Eurasia
Time period: Bartonian of the Eocene through to Rupelian of the Oligocene
Size: Around 3 meters long
Diet: Omnivore?

Genus: Uintatherium “Beast of the Uinta Mountains”
Classification: Family: Uinatatheriidae
Time: Eocene (Ypresian to Bartonian)
Location: China, Henan Province – Lushi Formation. USA – California, Texas, Utah, Wyoming.
Size: 1.70m (5.6 ft) Height
Diet: Herbivore
European Bartonian Stage 41.2 to 37.71 million years ago

Genus and species: Hyaenodon horridus
Name meaning: Hyena-tooth
Common name: Hyaenodon
Classification: Order: Hyaenodonta – Family: Hyaenodontidae
Time: Middle Eocene to Middle Miocene
Range: Eurasia, Africa, and North America
Diet: Carnivore

Genus and species: Eusmilus bidentatus
Common name: False Saber-toothed cat
Classification: Family: Nimravidae – Subfamily: Hoplophoninae
Time: Late Eocene to Early Oligocene
Range: Europe
Diet: Carnivore

Genus: Entelodon ”Perfect teeth”
Known locations: Eurasia
Time period: Bartonian of the Eocene through to Rupelian of the Oligocene
Size: Around 3 meters long
Diet: Omnivore?

Genus: Palaeotherium ”Ancient beast”
Known locations: Europe, France, Germany, Spain, Switzerland and the United Kingdom.
Time period: Eocene (Lutetian to Priabonian) and Oligocene (Rupelian )
Size: 120 centimeters long, 75 to 140 centimeters high at the shoulder
Diet: Herbivore
Lutetian Age/Stage
47.8 to 41.2 million years ago
The Lutetian Stage was named after the Latin name for the city of Paris by French geologist Albert de Lapparent in 1883.
North American Lutetian Stage 47.8 to 41.2 million years ago

Genus: Pristichampsus “saw crocodile“
Classification: Order: Crocodylia, Family: Pristichampidae
Time: Eocene (Lutetian)
Locality: Eurasia and North America
Size: 3 meters long
Diet: Carnivore

Genus and species: Hyaenodon horridus
Name meaning: Hyena-tooth
Common name: Hyaenodon
Classification: Order: Hyaenodonta – Family: Hyaenodontidae
Time: Middle Eocene to Middle Miocene
Range: Eurasia, Africa, and North America
Diet: Carnivore

Genus: Uintatherium “Beast of the Uinta Mountains”
Classification: Family: Uinatatheriidae
Time: Eocene (Ypresian to Bartonian)
Location: China, Henan Province – Lushi Formation. USA – California, Texas, Utah, Wyoming.
Size: 1.70m (5.6 ft) Height
Diet: Herbivore

Genus: Eobasileus “Dawn Emperor”
Classification: Family: Uinatatheriidae
Time: Eocene (Lutetian)
Location: United States of America
Size: 2.1m (6.9 ft) Height
Diet: Herbivore

Genus: Diatryma now Gastornis “Gaston’s bird”.
Named by: Edward Drinker Cope 1874 (Diatryma). Hébert - 1855 (Gastornis).
Classification: Order: Gastornithiformes- Family: Gastornithidae.
Time: Paleocene (Selandian) to Eocene (Lutetian)
Locality: USA.
Size: 2 meters tall.
Diet: Herbivore?

Genus: Gastornis “Gaston’s bird”.
Classification: Order: Gastornithiformes – Family: Gastornithidae.
Time: Paleocene (Selandian) to Eocene (Lutetian)
Locality: Belgium. China. England. France. Germany. USA.
Size: 2 meters tall.
Diet: Herbivore?
European Lutetian Stage 47.8 to 41.2 million years ago

Genus: Pristichampsus “saw crocodile“
Classification: Order: Crocodylia, Family: Pristichampidae
Time: Eocene (Lutetian)
Locality: Eurasia and North America
Size: 3 meters long
Diet: Carnivore

Genus and species: Hyaenodon horridus
Name meaning: Hyena-tooth
Common name: Hyaenodon
Classification: Order: Hyaenodonta – Family: Hyaenodontidae
Time: Middle Eocene to Middle Miocene
Range: Eurasia, Africa, and North America
Diet: Carnivore

Genus: Palaeotherium ”Ancient beast”
Known locations: Europe, France, Germany, Spain, Switzerland and the United Kingdom.
Time period: Eocene (Lutetian to Priabonian) and Oligocene (Rupelian )
Size: 120 centimeters long, 75 to 140 centimeters high at the shoulder
Diet: Herbivore

Genus: Gastornis “Gaston’s bird”.
Classification: Order: Gastornithiformes – Family: Gastornithidae.
Time: Paleocene (Selandian) to Eocene (Lutetian)
Locality: Belgium. China. England. France. Germany. USA.
Size: 2 meters tall.
Diet: Herbivore?
Asian Lutetian Stage 47.8 to 41.2 million years ago

Genus: Pristichampsus “saw crocodile“
Classification: Order: Crocodylia, Family: Pristichampidae
Time: Eocene (Lutetian)
Locality: Eurasia and North America
Size: 3 meters long
Diet: Carnivore

Genus and species: Hyaenodon horridus
Name meaning: Hyena-tooth
Common name: Hyaenodon
Classification: Order: Hyaenodonta – Family: Hyaenodontidae
Time: Middle Eocene to Middle Miocene
Range: Eurasia, Africa, and North America
Diet: Carnivore

Genus: Andrewsarchus (Andrew’s ruler)
Known locations: Mongolia
Time period: Eocene (Lutetian to Priabonian)
Size: Total size uncertain due to lack of remains. Skull is 83 centimeters long
Diet: Carnivore

Genus: Uintatherium “Beast of the Uinta Mountains”
Classification: Family: Uinatatheriidae
Time: Eocene (Ypresian to Bartonian)
Location: China, Henan Province – Lushi Formation. USA – California, Texas, Utah, Wyoming.
Size: 1.70m (5.6 ft) Height
Diet: Herbivore

Genus: Gastornis “Gaston’s bird”.
Classification: Order: Gastornithiformes – Family: Gastornithidae.
Time: Paleocene (Selandian) to Eocene (Lutetian)
Locality: Belgium. China. England. France. Germany. USA.
Size: 2 meters tall.
Diet: Herbivore?
African Stage 47.8 to 41.2 million years ago

Genus and species: Hyaenodon horridus
Name meaning: Hyena-tooth
Common name: Hyaenodon
Classification: Order: Hyaenodonta – Family: Hyaenodontidae
Time: Middle Eocene to Middle Miocene
Range: Eurasia, Africa, and North America
Diet: Carnivore
Ypresian Age/Stage
56.0 to 47.8 million years ago
The Ypresian Stage was named after the Flemish city of Ypres in Belgium by Belgian geologist Andre Hubert Dumont in 1850. The Ypresian is is the earilest stage in the Eocene Epoch.
North American Ypresian Stage 56.0 to 47.8 million years ago

Genus: Pristichampsus “saw crocodile“
Classification: Order: Crocodylia, Family: Pristichampidae
Time: Eocene (Lutetian)
Locality: Eurasia and North America
Size: 3 meters long
Diet: Carnivore

Genus: Uintatherium “Beast of the Uinta Mountains”
Classification: Family: Uinatatheriidae
Time: Eocene (Ypresian to Bartonian)
Location: China, Henan Province – Lushi Formation. USA – California, Texas, Utah, Wyoming.
Size: 1.70m (5.6 ft) Height
Diet: Herbivore

Genus: Gastornis “Gaston’s bird”.
Classification: Order: Gastornithiformes – Family: Gastornithidae.
Time: Paleocene (Selandian) to Eocene (Lutetian)
Locality: Belgium. China. England. France. Germany. USA.
Size: 2 meters tall.
Diet: Herbivore?

Genus: Diatryma now Gastornis “Gaston’s bird”.
Named by: Edward Drinker Cope 1874 (Diatryma). Hébert - 1855 (Gastornis).
Classification: Order: Gastornithiformes- Family: Gastornithidae.
Time: Paleocene (Selandian) to Eocene (Lutetian)
Locality: USA.
Size: 2 meters tall.
Diet: Herbivore?
European Ypresian Stage 56.0 to 47.8 million years ago

Genus: Pristichampsus “saw crocodile“
Classification: Order: Crocodylia, Family: Pristichampidae
Time: Eocene (Lutetian)
Locality: Eurasia and North America
Size: 3 meters long
Diet: Carnivore

Genus: Gastornis “Gaston’s bird”.
Classification: Order: Gastornithiformes – Family: Gastornithidae.
Time: Paleocene (Selandian) to Eocene (Lutetian)
Locality: Belgium. China. England. France. Germany. USA.
Size: 2 meters tall.
Diet: Herbivore?
Asian Ypresian Stage 56.0 to 47.8 million years ago

Genus: Pristichampsus “saw crocodile“
Classification: Order: Crocodylia, Family: Pristichampidae
Time: Eocene (Lutetian)
Locality: Eurasia and North America
Size: 3 meters long
Diet: Carnivore

Genus: Uintatherium “Beast of the Uinta Mountains”
Classification: Family: Uinatatheriidae
Time: Eocene (Ypresian to Bartonian)
Location: China, Henan Province – Lushi Formation. USA – California, Texas, Utah, Wyoming.
Size: 1.70m (5.6 ft) Height
Diet: Herbivore
