Plesiosaurus
- When: Early Jurassic
(199–175 mya) - Where: Europe
- What: Plesiosaur
- Weight: 450 kg
- Length: 3.5 meters
- Diet: Piscivorous
- Discovered: 1821
Plesiosauroid
Elasmosaurus
- When: Late Cretaceous
(80–65 mya) - Where: North America
- What: Plesiosaur
- Weight: 2–3 metric tons
- Length: 10–14 meters
- Diet: Piscivorous
- Discovered: 1868
Kronosaurus
- When: Early Cretaceous
(125–100 mya) - Where: Australia, South America
- What: Pliosaur
- Weight: 10–11 metric tons
- Length: 10 meters
- Diet: Carnivorous
- Discovered: 1924