Dino card No. 1463 of 2,027

Potamornis

Say it: poh-tuh-MOR-niss

Name means: “river bird”3

Ate: MeatEarly birdsLate Cretaceous

Potamornis was a small, toothed bird that lived near the end of the Age of Dinosaurs. It hunted along the shores of a river in what is now Wyoming, USA. It was a fast, meat-eating bird that could probably run and maybe fly a little.3

Lived

72 to 66 million years ago3

Late Cretaceous

Fossils found in

Wyoming, USA, in the Lance Formation3 1

Food

Meat3

Length

0.1 to 0.5 m1

estimated from the single partial skull, about 10 to 50 cm long

Weight

1.5 kg to 2 kg2

estimate

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 17 bananas

as long as 3 bananas end to endabout as heavy as a house catas heavy as 17 bananas

How big was Potamornis compared to YOU?

Just maths in your browser. Nothing is saved or sent anywhere.

cool stuff

Fun facts

Potamornis is known from just one partial skull bone, called a quadrate, which was found in Wyoming.3

It lived about 72 to 66 million years ago, right before the big extinction that killed the non-bird dinosaurs.1

Potamornis belonged to a group of ancient birds called Hesperornithiformes, which were mostly diving birds with teeth.3

The name Potamornis means 'river bird', because it was found in rocks that were once a riverbed.3

Scientists think Potamornis was a ground-dwelling bird that could run fast on land.3

It laid eggs, like all birds do, and probably built nests on the ground.1

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

?How big was Potamornis?

It was a small bird, weighing perhaps 1.5 or 2 kilograms (3.3 to 4.4 pounds).2

?Did Potamornis have teeth?

Yes, it was a toothed bird. It belonged to a group of ancient birds called Hesperornithiformes, which had teeth.2

?Could Potamornis fly?

Probably not. It was a flightless diving bird, like other members of its group, though some scientists think it might have been able to fly a little.2

?What did Potamornis eat?

It was a meat-eater (carnivore). It likely hunted for fish and other small animals in the water.3

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Myth buster

Myth: Some people think Potamornis was a dinosaur like T. rex.

Truth: Potamornis was a bird, and while birds are dinosaurs, it was a small, feathered, flying or running bird, not a big predator.3

For dino experts

Scientific name: Potamornis
Named by: Elzanowski et al. 20013
Group: Early birds
Family / clade: Hesperornithiformes3
Classification: Theropoda > Avialae3
Age of the rocks: 72 to 66 million years (Maastrichtian)3
Rock formations: Lance3
Countries: USA3
Fossil records: 1 in the Paleobiology Database3
Discovery: Potamornis was named by Elzanowski, Paul, and Stidham in 2001, based on a skull bone found in the Lance Formation of Wyoming.3
Still debated: Scientists are still not sure exactly how Potamornis is related to other ancient birds, because only a single skull bone has been found.3

Where the facts come from

PBDB Taxon (paleobiodb.org)
Potamornis (en.wikipedia.org)
Potamornis 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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