Irritator

Say it like this: “IHR-i-TAY-tor”

Irritator challengeri

Irritator ate meat and walked on two legs. It lived in the Early Cretaceous. Bones have been found in Brazil.

Quiz me on Irritator

When: Early Cretaceous (Aptian · Albian) · roughly 121.4 to 100.5 million years ago
Named in: 1996 · Martill, D. M.; Cruickshank, A. R. I.; Frey, E.; Small, P. G.; Clarke, M.
Hip height: 2 m · 7 ft
Length: 8 m · 26 ft
Weight: 0.9–3.6 tonnes
Found in: Brazil · Romualdo
Food and walking: Carnivore · Two legs
Kind: sharp-clawed runner · Theropod
Family branch: Spinosaurinae

The story in short

Irritator was formally named in 1996 by D. M. Martill and colleagues.

Fossils referred to Irritator date to the Early Cretaceous (Aptian · Albian), roughly 121.4 to 100.5 million years ago. Finds come from Brazil, including the Romualdo Formation. It was a carnivore and walked on two legs.

Published estimates put Irritator at a length near 8 m, hips about 2 m high, and a body mass around 0.9–3.6 tonnes.

On the family tree it sits in Spinosaurinae, among the theropod dinosaurs.

Close relatives

Ichthyovenator

Ichthyovenator laosensis

Early Cretaceous (Aptian) · roughly 121.4 to 113.2 million years ago

Oxalaia

Oxalaia quilombensis

Late Cretaceous (Cenomanian) · roughly 100.5 to 93.9 million years ago

Sigilmassasaurus

Sigilmassasaurus brevicollis

Late Cretaceous (Cenomanian) · roughly 100.5 to 93.9 million years ago