Dino card No. 1854 of 2,027

Ugrunaaluk

Say it: oo-GREW-nah-luk

Name means: “ancient grazer”1

Ate: PlantsDuck-billsLate Cretaceous

Ugrunaaluk was a duck-billed dinosaur that lived in the ancient Arctic, where it was cold and dark for part of the year. It had a long, flat beak and hundreds of teeth for chewing tough plants. This dinosaur is special because it shows that some dinosaurs could survive in polar regions.5 1

Lived

72 to 66 million years ago5

Late Cretaceous

Fossils found in

Liscomb Quarry, Prince Creek Formation, northern Alaska, USA5 1

Food

Plants5 1

Length

9 to 12 m2 3

adult length range for Edmontosaurus regalis; larger specimens up to 13 m reported

Weight

4 tonnes to 5.6 tonnes2 3

average asymptotic body mass for E. annectens; E. regalis around 4.0 metric tons

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 4 cars

as long as 2.5 cars parked in a rowas long as 67 bananas end to endabout as heavy as an elephantas heavy as 1100 watermelons

How big was Ugrunaaluk compared to YOU?

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cool stuff

Fun facts

Ugrunaaluk lived in the Arctic about 69 million years ago, when the climate was much cooler than today, with average temperatures around 5 to 6°C.1

Most of the Ugrunaaluk fossils found are from young animals, not fully grown adults. Scientists think a whole herd of juveniles may have died together in a flood.1

Its name comes from the Iñupiaq language of Alaska. Ugruŋnaq means a grazing animal with grinding teeth, and -aluk means old, so Ugrunaaluk is 'ancient grazer'.1

Ugrunaaluk was a close relative of Edmontosaurus, but scientists found enough differences in its skull bones to give it its own name.1

The Liscomb bonebed where Ugrunaaluk was found has thousands of bones, mostly from this dinosaur, along with a few teeth from tyrannosaurs and other small dinosaurs.1

During the time of Ugrunaaluk, the Arctic had polar woodlands with flowering plants in the understory, and the days were dark for months in winter.1

AI-made picture of Ugrunaaluk — An AI-made picture of how Ugrunaaluk 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 Ugrunaaluk

?How big was Ugrunaaluk?

Ugrunaaluk was about 7.6 to 9.1 meters (25 to 30 feet) long and stood about 1.8 to 2.1 meters (6 to 7 feet) tall at the hip.4

?What did Ugrunaaluk eat?

It was a plant-eater, with a flat beak and hundreds of teeth for chewing tough plants. Its jaw had at least 1,000 teeth with coarse surfaces perfect for pulverizing plants.4

?Did Ugrunaaluk live in the Arctic?

Yes, Ugrunaaluk lived in the ancient Arctic, above the Arctic Circle, about 69 million years ago. It endured cold and dark winters, with average temperatures around 5 to 6°C.4 1

?Was Ugrunaaluk a duck-billed dinosaur?

Yes, Ugrunaaluk belonged to the hadrosaur group of duck-billed dinosaurs. It had a long, flat beak and hundreds of teeth for chewing plants.4

?Why is Ugrunaaluk special?

Ugrunaaluk is special because it shows that some dinosaurs could survive in polar regions. It lived above the Arctic Circle, enduring months of darkness and cold.4

?How many teeth did Ugrunaaluk have?

Ugrunaaluk had at least 1,000 teeth in its jaw, with coarse surfaces perfect for pulverizing plants.4

?When did Ugrunaaluk live?

Ugrunaaluk lived about 69 million years ago, during the Late Cretaceous period, in the ancient Arctic.4

?Is Ugrunaaluk related to Edmontosaurus?

Yes, Ugrunaaluk is closely related to Edmontosaurus, but scientists found enough differences in its skull bones to give it its own name.1

?Where was Ugrunaaluk found?

Ugrunaaluk fossils were found in the Liscomb bonebed in the Prince Creek Formation of northern Alaska, along the Colville River.1

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Myth buster

Myth: Ugrunaaluk is just a young Edmontosaurus and not a real separate dinosaur.

Truth: Scientists showed that Ugrunaaluk has unique skull features that make it a distinct species, even when accounting for age differences.1

For dino experts

Scientific name: Ugrunaaluk
Named by: Mori et al. 20165
Group: Duck-bills
Family / clade: Hadrosauridae5
Classification: Ornithischia > Ornithopoda > Iguanodontia > Hadrosauridae5
Age of the rocks: 72 to 66 million years (Maastrichtian)5
Rock formations: Prince Creek5
Countries: USA5
Fossil records: 1 in the Paleobiology Database5
Discovery: Ugrunaaluk was named in 2016 by Hirotsugu Mori, Patrick Druckenmiller, and Gregory Erickson. The fossils were found in the Liscomb bonebed along the Colville River in northern Alaska.5 1
Still debated: Scientists are not sure exactly how big adult Ugrunaaluk grew, because almost all the fossils are from juveniles.1

Where the facts come from

Formation (lower Maastrichtian) of northern Alaska (app.pan.pl)
Edmontosaurus (en.wikipedia.org)
Edmontosaurus regalis (en.wikipedia.org)
New Dinosaur Species Probably Endured Snow and Darkness for Months on End | NOVA | PBS (pbs.org)
Ugrunaaluk 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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