THE PREHISTORIC A–Z

Explore the letter O

A research index of dinosaur genus names, including names whose status has changed.

ARTISTIC RECONSTRUCTION

1,888 names catalogued from Wikipedia’s genus list on 11 October 2026. Inclusion does not establish that a name is a valid dinosaur genus. Historical or disputed names are marked for review. Names without a field note link go to the source overview.

Obelignathus ↗Source index entry
Oblitosaurus ↗Source index entry
Oceanotitan ↗Source index entry
Ohmdenosaurus ↗Source index entry
Ojoceratops ↗Historical / disputed: review source
Ojoraptorsaurus ↗Source index entry
Oksoko ↗Source index entry
Oligosaurus ↗Historical / disputed: review source
Olorotitandinosaur · Cretaceous
Omeisaurusdinosaur · Jurassic
Omosaurus ↗Historical / disputed: review source
Ondogurvel ↗Source index entry
Onychosaurus ↗Historical / disputed: review source
Oohkotokia ↗Source index entry
Opisthocoelicaudiadinosaur · Cretaceous
Oplosaurus ↗Source index entry
Orcomimus ↗Historical / disputed: review source
Orinosaurus ↗Historical / disputed: review source
Orkoraptor ↗Source index entry
Ornatops ↗Source index entry
Ornatotholus ↗Historical / disputed: review source
Ornithodesmus ↗Source index entry
Ornithoides ↗Historical / disputed: review source
Ornitholestes ↗Source index entry
Ornithomerus ↗Historical / disputed: review source
Ornithomimoides ↗Source index entry
Ornithomimusdinosaur · Cretaceous
Ornithopsis ↗Source index entry
Ornithosuchus ↗Historical / disputed: review source
Ornithotarsus ↗Historical / disputed: review source
Orodromeus ↗Source index entry
Orosaurus ↗Source index entry
Orthogoniosaurus ↗Source index entry
Orthomerus ↗Source index entry
Oryctodromeus ↗Source index entry
Oshanosaurus ↗Historical / disputed: review source
Osmakasaurus ↗Source index entry
Ostafrikasaurus ↗Source index entry
Ostromia ↗Source index entry
Othnielia ↗Historical / disputed: review source
Othnielosaurus ↗Historical / disputed: review source
Otogosaurus ↗Historical / disputed: review source
Ouranosaurusdinosaur · Cretaceous
Overoraptor ↗Source index entry
Overosaurus ↗Source index entry
Oviraptordinosaur · Cretaceous
Ovoraptor ↗Historical / disputed: review source
Owenodon ↗Source index entry
Oxalaiadinosaur · Cretaceous
Ozraptor ↗Source index entry