Genus: Irritator MARTILL, CRUICKSHANK, FREY, SMALL & CLARKE, 1996
Etymology: From irritation, the feeling the authors felt (understated here) when discovering that the snout hand been artificially elongated.

Species: challengeri MARTILL, CRUICKSHANK, FREY, SMALL & CLARKE, 1996
Etymology: From Professor Challenger, the fictitious hero and dinosaur discoverer of Sir Arthur Conan-Doyle’s Lost World.

Holotype: SMNS 58022

Locality: Chapade do Araripe, Ceara, Northeastern Brazil.

Horizon: Romualdo Member, Santana Formation, Araripe Group.

Biostratigraphy:

Age: Late Aptian or Early Albian Stage, Middle Gallic Subepoch, Upper Early Cretaceous Epoch, Early Cretaceous.

Material: Fragmentary skull and fragmentary dentary.