Megaraptor, Late CretaceousPortezuelo Formation, Argentina · named 1998
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Megaraptor

MEG-ah-RAP-tor

"giant thief"

Lived
94 to 86 million years ago, Late Cretaceous
Diet
Carnivore
Length
about 8 m (26 ft)
Group
Theropods, Megaraptoridae
Found in
Argentina
Named by
Novas 1998

Size comparison

To scale

Where its fossils were found

The evidence

Today

3 finds

90 million years ago

Map: C. R. Scotese, PALEOMAP

Habitat

It lived on river plains in the Portezuelo Formation of Argentina, with channel banks, sandbars and open woodland. Futalognkosaurus, Unenlagia and Patagonykus lived in the same region.

Field notes

About Megaraptor

What it was like

Megaraptor is best known for its huge, strongly curved hand claws, among the largest of any theropod. When it was first described, paleontologists thought the claw came from the foot and pictured Megaraptor as a giant relative of Velociraptor. Later discoveries showed the claw actually belonged to the hand.

Since then, scientists have kept revising where Megaraptor fits on the dinosaur family tree, and where exactly the group it named, the megaraptorans, belongs is still debated. Its long, low skull and small eye sockets in known juvenile remains suggest it grew a deeper, sturdier skull as an adult, and it probably used its powerful arms and claws to grab prey.

Its world

Megaraptor lived from about 94 to 86 million years ago, in the Late Cretaceous, in what is now Argentina. Its fossils come from the Portezuelo Formation.

It shared its river habitat with the giant sauropod Futalognkosaurus, the small hunters Unenlagia, Neuquenraptor, and Patagonykus, and other local dinosaurs such as Pamparaptor, Elemgasem, and Baalsaurus.

How it was found

Novas named Megaraptor in 1998, and only about three fossil finds of the genus are known, most of them fragmentary. Even so, it gave its name to an entire group of similar clawed predators found across South America and beyond, including relatives such as Australovenator and Orkoraptor.

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 Megaraptor.

The evidence

The science behind Megaraptor

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

From its own fossils

  • Arm and hand bones show long, powerful forelimbs with greatly enlarged curved claws.
  • A young specimen preserves parts of the skull and body skeleton.

Borrowed from relatives

  • Missing parts of the adult body are restored by comparison with megaraptorids such as Australovenator and Murusraptor.
  • The adult head is partly inferred from the young specimen and other megaraptorids.

Still unknown

  • Its full adult size and the shape of the mature skull.
  • Its skin covering and color.
  • The exact position of megaraptorans within the theropod family tree.

Often drawn wrong

  • Its huge claws belong on the hands rather than on raised second toes like those of Velociraptor.
  • Its long arms and grasping hands should not be replaced with tiny tyrannosaur arms.

Discovery timeline

  1. 1998Named itNovas
  2. 2014Growing upPorfiri et al.
  3. 2016Family treeNovas, Rolando & Agnolín

Key papers

The research behind what we know of Megaraptor

Close relatives

Other members of Megaraptoridae

Sources: Wikidata