Stegosaurus
- When: Late Jurassic
(155–150 mya) - Where: North America
- What: Stegosaur
- Weight: 4.5–7 tons
- Length: 7–9 meters
- Diet: Herbivorous
- Discovered: 1877
Styracosaurus
- When: Late Cretaceous
(75–74 mya) - Where: North America
- What: Ceratopsian
- Weight: 3 tons
- Length: 5–5.5 meters
- Diet: Herbivorous
- Discovered: 1913
Suchomimus
- When: Early Cretaceous
(125–112 mya) - Where: Africa
- What: Theropod
- Weight: 3.6–5.2 metric tons
- Length: 11 meters
- Diet: Piscivorous
- Discovered: 1998
Supersaurus
- When: Late Jurassic
(153–150 mya) - Where: North America
- What: Sauropod
- Weight: 35–40 metric tons
- Length: 33–34 meters
- Diet: Herbivorous
- Discovered: 1985
Tanystropheus
- When: Middle to Late Triassic
(242–227 mya) - Where: Europe
- What: Archosaur marine reptile
- Weight: 60–100 kg
- Length: 6 meters
- Diet: Carnivorous or piscivorous
- Discovered: 1906
Tarbosaurus
- When: Late Cretaceous
(70–65 mya) - Where: Asia
- What: Tyrannosaurid theropod
- Weight: 4–6 tons
- Length: 10–12 meters
- Diet: Carnivorous
- Discovered: 1955
Thecodontosaurus
- When: Late Triassic
(205–201 mya) - Where: Europe
- What: Sauropodomorph
- Weight: 10–20 kg
- Length: 2 meters
- Diet: Herbivorous
- Discovered: 1836
Therizinosaurus
- When: Late Cretaceous
(70–66 mya) - Where: Asia
- What: Theropod
- Weight: 3–5 metric tons
- Length: 10–12 meters
- Diet: Likely herbivorous or omnivorous
- Discovered: 1954
Titanis
- When: Pliocene to Pleistocene
(5–2 mya) - Where: North America
- What: Bird
- Weight: 150 kg
- Length: 2.5 meters
- Diet: Carnivorous
- Discovered: 1963