Glowing Dinosaursby Firoiu Dan Nicolae Reserve a copy
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Feathered Deinonychus in purple and pink, running, with wing feathers on its arms

N° 031 · II. Raptors and Feathers

Deinonychus

The Game Changer

Say it: dye-NON-ick-us

Species
Deinonychus antirrhopus, Ostrom 1969
Name means
Terrible claw
Lived
Early Cretaceous, about 115 to 108 million years ago
Found
United States
Length
About 3.4 m
Weight
About 100 kg
Diet
Carnivore

Three things to know

The find that changed minds

Found in Montana in 1964 and named in 1969, it helped scientists see dinosaurs as athletic and warm-blooded rather than slow and cold-blooded.

A claw for pinning prey

A 2011 study compared its foot with those of eagles and hawks. The big claw probably gripped prey while the hunter’s weight pinned it down.

Pack hunter? Probably not

In 2020 the chemistry of its teeth showed that young and adults ate different food, which animals hunting as a pack rarely do.

Every fact on this page is traced to a published source, listed at the back of the book.

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When and where Deinonychus lived

Deinonychus lived about 115 to 108 million years ago, in the Early Cretaceous, in what is now the western United States. Its fossils come mostly from the Cloverly Formation of Montana and Wyoming, which records river plains with forests of conifers, ferns and early flowering plants. Its remains are often found alongside those of Tenontosaurus, a large plant-eating dinosaur that may have been among its prey.

How Deinonychus was discovered and named

A team led by John Ostrom and Grant Meyer of Yale University found the first good skeletons in Montana in 1964, and Ostrom named Deinonychus, the terrible claw, in 1969. His description of a fast, agile and bird-like hunter started what became known as the dinosaur renaissance, a new view of dinosaurs as active animals, and revived the idea that birds are living dinosaurs.

How Deinonychus lived

Deinonychus was about three metres long, with a long, stiffened tail, grasping arms that carried feathers, and a large sickle-shaped claw on each foot. Like modern birds of prey, it probably used that claw to pin its victim down while it fed. The raptors of the Jurassic Park films were modelled largely on Deinonychus, even though they were given the name of its smaller Asian cousin.

Deinonychus in Glowing Dinosaurs

Deinonychus is entry N° 031 of the atlas, in the chapter II. Raptors and Feathers. Its spread follows the same layout as every other dinosaur in the book: on the left, its name and how to say it, the epithet The Game Changer, the three facts above, field notes and the six signs that show when it lived, how big it was, how dangerous it would have been, where it was found, what it ate and how it fought. On the right is the full glowing plate: feathered Deinonychus in purple and pink, running, with wing feathers on its arms. Two more plates of Deinonychus appear elsewhere in the book, and each can also be ordered as a signed work for the wall, printed on wood or acrylic under glass. In the same chapter you will also find Velociraptor.

Why Deinonychus glows

No dinosaur is known to have glowed, and the book says so plainly. The light is the artist’s way of seeing inside the animal: in the plate of Deinonychus, bones, muscles and outline shine through a dark ground, so the shape of the skull, the length of the neck and tail and the build of the legs can be read at once, the way a fossil skeleton is read in a museum hall. The colours are chosen to separate bone from muscle and to make each animal recognisable across the whole atlas, while every fact printed beside the picture is checked against published research.

Questions about Deinonychus

How big was Deinonychus?

Deinonychus measured about 3.4 m from nose to tail and weighed about 100 kg. The size panel on its spread in the book draws it beside a person, so its scale can be seen at a glance.

When did Deinonychus live?

It lived in the Early Cretaceous, about 115 to 108 million years ago. On the timeline in the book, its place is marked between the first dinosaurs, about 230 million years ago, and the end of the age of dinosaurs, 66 million years ago.

Where have Deinonychus fossils been found?

Its fossils have been found in United States. The map on its spread in the book marks the places where its bones were dug up.

What did Deinonychus eat?

Its diet: carnivore. The diet sign in the book shows this with a simple symbol, so young readers can sort the plant-eaters from the meat-eaters.

What does the name Deinonychus mean?

The name means “terrible claw”. The full scientific name is Deinonychus antirrhopus, Ostrom 1969: the genus, the species and the scientist who named it, with the year. It is pronounced dye-NON-ick-us.

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