Dinosaurs · Large theropod

Irritator

Say it irr-it-ate-or. The name means ‘irritator’.

Irritator beside a person 1.75 m tall. Ticks mark every metre.Body shape drawn for this site, showing the general build of large theropods

Length: 6.5 m
Diet: Meat-eater
When: Early Cretaceous112 to 99 million years ago
Fossils found in: Brazil
Named by: Martill, Cruickshank, Frey, Small and Clarke (1996)
Family tree: Dinosauria › Saurischia › Theropoda › Spinosauridae › Spinosaurini

Where Irritator sits in the age of dinosaurs.Periods from the ICS chart; dinosaur dates from the Natural History Museum

Large theropods. Big two-legged meat-eaters, such as Tyrannosaurus. See all 63

Lived at the same time

Other large theropods

Acrocanthosaurus Early Cretaceous
Fukuiraptor Early Cretaceous
Suchomimus Early Cretaceous
Tyrannotitan Early Cretaceous
Giganotosaurus Late Cretaceous
Achillobator Late Cretaceous
Baryonyx Early Cretaceous
Carcharodontosaurus Late Cretaceous

Source: Irritator in the Natural History Museum Dino Directory, read 12 November 2026. Sizes are the museum's estimates for a typical adult. "Lived at the same time" lists dinosaurs whose dates overlap, which does not always mean they met.