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Orkoraptor, Late CretaceousCerro Fortaleza Formation, Argentina · named 2008
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Orkoraptor

Lived
84 to 72 million years ago, Late Cretaceous
Diet
Carnivore
Group
Theropods, Megaraptoridae
Found in
Argentina
Named by
Novas et al. 2008

Where its fossils were found

The evidence

Today

1 find

80 million years ago

Map: C. R. Scotese, PALEOMAP

Habitat

It lived on river floodplains in southern Argentina. Other dinosaurs from the Cerro Fortaleza Formation include Puertasaurus, Dreadnoughtus and Talenkauen.

Field notes

About Orkoraptor

What it was like

Orkoraptor was a medium-sized meat eater known only from scattered pieces: bits of the skull, some teeth, tail bones and part of a shin bone. Its teeth were unusual, with shapes more like those of much smaller hunters.

Its world

It lived about 84 to 72 million years ago, in the Late Cretaceous, in what is now southern Argentina. Its bones come from the Cerro Fortaleza Formation, where giant titanosaurs such as Dreadnoughtus and Puertasaurus lived. It is one of the most southerly meat-eating dinosaurs known from South America.

How it was found

Novas and colleagues named Orkoraptor in 2008. At first they placed it among the small, bird-like coelurosaurs, but later studies grouped it with the megaraptors, big-clawed hunters such as Megaraptor and Aerosteon.

Field gallery

More views of Orkoraptor

Scenes reconstructed from the available fossil evidence.

Orkoraptor in its habitat, photo 1

1 of 3

Lived alongside

Found in the same rock formations

A rock formation can hold fossils laid down millions of years apart, so not every animal here met Orkoraptor.

The evidence

The science behind Orkoraptor

Which parts of the picture come from its own bones, and which come from its relatives.

From its own fossils

  • The type specimen includes pieces of the skull, a fragment that is probably from the lower jaw, teeth, part of the first neck vertebra, tail vertebrae, ribs and part of a shin bone.
  • Its teeth have narrow grooves on their inner surfaces and lack serrations along the front edge.
  • The bone behind the eye is broad with little surface texture, and the preserved tail vertebrae have small openings in their sides.

Borrowed from relatives

  • The missing arms and hands are restored by comparison with Megaraptor and Australovenator, relatives with large hand claws.
  • Much of the body outline follows better-known megaraptors such as Aerosteon.

Still unknown

  • The complete shape of its skull and hands, and whether one skull fragment comes from the lower jaw or from the top of the snout.
  • Its skin covering and color.
  • How it caught and handled prey.

Discovery timeline

  1. 2008Named itNovas, Ezcurra & Lecuona
  2. 2009Family treeBenson, Carrano & Brusatte
  3. 2013Family treeNovas et al.
  4. 2025Close relativeIbiricu et al.

Key papers

The research behind what we know of Orkoraptor

Close relatives

Other members of Megaraptoridae

Sources: Wikidata