Feature Allosaurus fragilis Tyrannosaurus rex Period Late Jurassic, approximately 155–145 Ma Late Cretaceous, approximately 68–66 Ma Length Approximately 8.5–10 m (28–33 ft) Approximately 12–13 m (39–43 ft) Mass Approximately 1,500–3,500+ kg (3,300–7,700+ lb), depending on specimen and reconstruction Approximately 8,000–14,000 kg (17,600–30,900 lb), depending on specimen and reconstruction Bite force (estimated) Significantly lower than T. … Read more
Field Information Species Allosaurus (best-documented species: Allosaurus fragilis) — Saurischia, Allosauridae Period Late Jurassic, approximately 155–145 million years ago (Ma) Stage range Primarily Kimmeridgian to Tithonian Extinction Extinct by the end of the Jurassic fossil record; no confirmed survival into the Cretaceous Quick Answer:Allosaurus lived during the Late Jurassic, approximately 155 to 145 million years … Read more
Field Information Species Allosaurus fragilis — Saurischia, Allosauridae Period Late Jurassic, 155–145 Ma First described Marsh, 1877 Type locality Morrison Formation, Colorado, USA Named species A. fragilis (1877); A. jimmadseni (2020) Quick Answer:Allosaurus was formally named in 1877 when paleontologist Othniel Charles Marsh described the genus from fragmentary fossil material recovered in Colorado’s Morrison Formation. … Read more
Field Information Species Allosaurus fragilis — Saurischia, Allosauridae Period Late Jurassic, 155–145 Ma Formation Morrison Formation, western North America Climate Semi-arid with seasonal wet periods Quick Answer:Allosaurus inhabited the Morrison Formation of western North America — a vast Late Jurassic ecosystem spanning much of what is now the western United States. Paleoenvironmental evidence indicates a … Read more
Field Information Species Allosaurus fragilis — Saurischia, Allosauridae Period Late Jurassic, 155–145 Ma Estimated bite force 1,500–8,000 N (337–1,799 lbf) — model dependent Estimated top speed 19–34 km/h (12–21 mph) Quick Answer:Allosaurus bite force estimates vary significantly depending on the biomechanical model applied, with published figures ranging from approximately 1,500 to 8,000 newtons (337–1,799 lbf). … Read more
Field Information Species Allosaurus fragilis — Saurischia, Allosauridae Period Late Jurassic, 155–145 Ma Diet Carnivorous — large herbivorous dinosaurs Key prey evidence Tooth marks on sauropod and ornithopod bones Quick Answer:Allosaurus was a carnivorous theropod that fed primarily on herbivorous dinosaurs within the Morrison Formation ecosystem. Fossil evidence directly links it to feeding on sauropods … Read more
Field Information Species Allosaurus fragilis — Saurischia, Allosauridae Pronunciation AL-oh-SORE-us Name meaning “Different lizard” — from Greek allos (different) and sauros (lizard) Named by Othniel Charles Marsh, 1877 Quick Answer: Allosaurus pronunciation is AL-oh-SORE-us, with the stress falling on the first and third syllables. The name combines the Greek words allos, meaning “different,” and sauros, … Read more
Field Information Species Allosaurus fragilis — Saurischia, Allosauridae Period Late Jurassic, 155–145 Ma Integument evidence No direct skin impression evidence for Allosaurus Cranial ornamentation Low lacrimal crests; rugose nasal ridge — fossil evidence confirmed Quick Answer: Did Allosaurus have feathers? No direct fossil evidence confirms feathers on Allosaurus. Its phylogenetic position within Carnosauria, combined with … Read more
Field Information Species Allosaurus fragilis — Saurischia, Allosauridae Period Late Jurassic, 155–145 Ma Average adult length 8.5–9 m (28–30 ft) Estimated adult mass 1,500–2,500 kg (3,300–5,500 lb) Hip height approximately 2.5 m (8.2 ft) Quick Answer: Allosaurus size in typical adults reached around 8.5–9 metres (28–30 ft) in length, with a mass estimated at 1,500–2,500 … Read more
At a Glance Field Q. northropi Q. lawsoni Clade / Family Pterosauria / Azhdarchidae Pterosauria / Azhdarchidae Geological age Late Cretaceous (Maastrichtian), approximately 68–66 million years ago Late Cretaceous (Maastrichtian), approximately 68–66 million years ago Estimated wingspan Approximately 10–11 m (33–36 ft) Approximately 4.5–5.5 m (15–18 ft) Estimated mass Commonly modeled at approximately 180–250 kg … Read more