Archelon
- When: Late Cretaceous
(80–66 mya) - Where: North America
- What: Turtle
- Weight: 2.2 metric tons
- Length: 4.5 meters
- Diet: Omnivorous
- Discovered: 1896
Argentinosaurus
- When: Late Cretaceous
(93–89 mya) - Where: South America
- What: Sauropod
- Weight: 70–100 tons
- Length: 30–35 meters
- Diet: Herbivorous
- Discovered: 1993
Barosaurus
- When: Late Jurassic
(155–150 mya) - Where: North America
- What: Sauropod
- Weight: 20 metric tons
- Length: 26 meters
- Diet: Herbivorous
- Discovered: 1890
Baryonyx
- When: Early Cretaceous
(130–125 mya) - Where: Europe
- What: Theropod
- Weight: 1.2–1.7 tons
- Length: 7.5–10 meters
- Diet: Carnivorous
- Discovered: 1986
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
Brachiosaurus
- When: Late Jurassic
(154–150 mya) - Where: North America
- What: Sauropod
- Weight: 28–58 tons
- Length: 20–25 meters
- Diet: Herbivorous
- Discovered: 1903
Brontosaurus
- When: Late Jurassic
(156–145 mya) - Where: North America
- What: Sauropod
- Weight: 15 metric tons
- Length: 22 meters
- Diet: Herbivorous
- Discovered: 1879