Dino card No. 0799 of 2,027

Hesperonychus

Say it: HES-per-oh-NYE-kus

Name means: “western claw”1

Ate: MeatRaptorsLate Cretaceous

Hesperonychus was a tiny, feathered dinosaur that lived in what is now Canada. It was one of the smallest meat-eating dinosaurs ever found in North America, about the size of a chicken.1

Lived

84 to 72 million years ago4

Late Cretaceous

Fossils found in

Alberta, Canada, in the Dinosaur Park Formation and Oldman Formation1 2

Food

Meat4

Length

1 m3

estimate

Weight

1.9 kg1

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

How long was it?

How heavy was it?

as heavy as 16 bananas

as long as 2 house cats nose to tailas long as 6 bananas end to endlighter than a house catas heavy as 16 bananas

How big was Hesperonychus compared to YOU?

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cool stuff

Fun facts

Hesperonychus weighed only about 1.9 kilograms, which is less than a house cat.1

It is the smallest carnivorous non-avian dinosaur known from North America.1

Hesperonychus belongs to a group called Microraptorinae, which includes the four-winged Microraptor from China.1

Its fossils were first collected in 1982 but were not studied until 25 years later.1

Hesperonychus lived about 75 million years ago during the Late Cretaceous.1

Even though it was fully grown, its hip bones were fused together, showing it was an adult.1

AI-made picture of Hesperonychus — An AI-made picture of how Hesperonychus might have looked, made by a computer from what scientists know. It is a guess: the real animal may have looked different, and nobody knows its true colours.

you asked

Most asked questions about Hesperonychus

?How big was Hesperonychus?

About 1 metre long and weighed between 1.5 and 2 kilograms, roughly the size of a large cat.3 1

?What did Hesperonychus eat?

It was a meat-eater. It ate small animals like lizards, mammals, and insects.3 1

?Did Hesperonychus have feathers?

Yes, it almost certainly had feathers. It belonged to a group of feathered dinosaurs called Microraptorinae, which includes the four-winged Microraptor.3 1

?Could Hesperonychus fly?

Probably not. Scientists think it was more like a ground-running predator, not a glider like its relative Microraptor.3

?When did Hesperonychus live?

It lived about 75 million years ago, during the Late Cretaceous period.3 1

?Is Hesperonychus a dinosaur?

Yes, it is a small, meat-eating dinosaur called a dromaeosaurid. It is not a bird, even though it had feathers.3 1

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For dino experts

Scientific name: Hesperonychus
Named by: Longrich and Currie 20094
Group: Raptors
Family / clade: Dromaeosauridae4
Classification: Theropoda > Dromaeosauridae4
Age of the rocks: 84 to 72 million years (Campanian)4
Rock formations: Dinosaur Park, Oldman4
Countries: Canada4
Fossil records: 4 in the Paleobiology Database4
Discovery: The holotype was collected in 1982 by Dr. Elizabeth Nicholls, but it was not described until 2009 by Nicholas Longrich and Philip Currie. The species name honors Elizabeth Nicholls.1 3
Still debated: Scientists are not sure exactly how many small dromaeosaurids lived in North America, because only isolated bones have been found so far.1

Where the facts come from

A microraptorine (Dinosauria, Dromaeosauridae) from the Late Cretaceous of North America (pmc.ncbi.nlm.nih.gov)
A microraptorine (Dinosauria, Dromaeosauridae) from the Late Cretaceous of North America (pnas.org)
Hesperonychus (en.wikipedia.org)
Hesperonychus in The Paleobiology Database (CC BY 4.0): age, places, rock formations, classification.

Every fact on this page has a number that points to its source. If we got something wrong, sorry, we are dino fans, not a science journal. Tell us at [email protected] and we will fix it.

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