Dino card No. 0073 of 2,027

Alexornis

Say it: al-EX-OR-nis

Name means: “Alex's ancestral bird”1

Ate: MeatEarly birdsLate Cretaceous

Alexornis was a tiny bird that lived during the Late Cretaceous in what is now Mexico. It was about the size of a sparrow and probably ate insects or other small animals. This bird is special because it belongs to a group called enantiornithines, which had a backwards shoulder joint compared to modern birds.1 3

Lived

86 to 84 million years ago3

Late Cretaceous

Fossils found in

Southwest of El Rosario, Baja California, Mexico (La Bocana Roja Formation)3 1

Food

Meat3

Weight

0.0356 kg1

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

How heavy was it?

as heavy as 0.5 bananas

lighter than a house cat

How big was Alexornis compared to YOU?

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

cool stuff

Fun facts

Alexornis is known from only one partial skeleton, which includes shoulder, wing, and leg bones, but no skull.1

It weighed only about 35.6 grams, which is roughly the same as a modern sparrow.1

When first discovered, scientists thought Alexornis was an ancestor of kingfishers and woodpeckers, but later studies showed it was an enantiornithine bird.1

Enantiornithines like Alexornis had a reversed joint between the shoulder blade and the collarbone, which confused early researchers.1

The fossil was discovered in 1971 and formally described in 1976 by paleontologist Pierce Brodkorb.1

Alexornis lived during the Santonian age of the Late Cretaceous, about 85 to 83 million years ago.3

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

?How big was Alexornis?

About the size of a sparrow, weighing roughly 35.6 grams.1

?What did Alexornis eat?

Scientists think it probably ate insects or other small animals, based on its small size and bird-like features.1

?Was Alexornis a dinosaur?

Alexornis was a bird, and birds are a type of dinosaur called avialan dinosaurs. So yes, it was a dinosaur.1

?When did Alexornis live?

It lived during the Late Cretaceous, about 85 to 83 million years ago.1

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Myth buster

Myth: Some people thought Alexornis was a modern bird ancestor.

Truth: Actually, Alexornis is an enantiornithine, a group of ancient birds that went extinct with the dinosaurs.1

For dino experts

Scientific name: Alexornis
Named by: Brodkorb 19763
Group: Early birds
Family / clade: Alexornithidae3
Classification: Theropoda > Avialae3
Age of the rocks: 86 to 84 million years (Santonian)3
Rock formations: La Bocana Roja3
Countries: Mexico3
Fossil records: 1 in the Paleobiology Database3
Discovery: The only known fossil of Alexornis was found in 1971 near El Rosario, Baja California, Mexico. It was named and described in 1976 by Pierce Brodkorb, who thought it was an ancestor of modern kingfishers and woodpeckers.1 2
Still debated: Scientists are still unsure exactly how Alexornis is related to other enantiornithine birds, especially those from South America and Central Asia.1

Where the facts come from

Alexornis (en.wikipedia.org)
repository.si.edu (repository.si.edu)
Alexornis 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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