Basilosaurus
- When: Eocene
(41–34 mya) - Where: North America, Africa
- What: Cetacean Mammal
- Weight: 15–20 metric tons
- Length: 15–20 meters
- Diet: Carnivorous
- Discovered: 1834
Cetacean
Livyatan
- When: Miocene
(9–8 mya) - Where: South America
- What: Cetacean Mammal
- Weight: 50 metric tons
- Length: 13–18 meters
- Diet: Carnivorous
- Discovered: 2010
Perucetus
- When: Eocene
(37–34 mya) - Where: South America
- What: Cetacean Mammal
- Weight: 200 metric tons
- Length: 17–20 meters
- Diet: Carnivorous
- Discovered: 2023
