Fun Avisaurus Facts For Kids

Mellisa Nair
Oct 20, 2022 By Mellisa Nair
Originally Published on Oct 19, 2021
Edited by Hannah Bowyer
Interesting Avisaurus facts include details about its history, diet, length, range, and era.
Age: 3-18
Read time: 5.5 Min

The Avisaurus (bird-lizard) is an extinct genus of Cretaceous birds that belonged to the group called enantiornithines. This enantiornithine bird lived during the Late Cretaceous, approximately 70.6 to 66 million years ago in North America.

It was originally described by Michael K. Brett-Surman and Paul in 1985, but was not yet considered as an enantiornithine.

In fact, this idea was strongly opposed until later when the fossils of A. archibaldi and Soroavisaurus were studied together, and it was revealed that they both lived during the Late Cretaceous, however in separate regions (North and South America).

The specific name Avisaurus archibaldi honors J. David Archibald, who discovered it near the Hell Creek Formation in Garfield County, Montana, USA.

For more related content, check out these Caviramus facts and Ludodactylus facts for kids.

Avisaurus Interesting Facts

Was the Avisaurus a dinosaur?

No, it was a bird that co-existed with several dinosaurs during the Cretaceous. It belonged to an ancient group of birds called enantiornithines, that lived in the Upper Cretaceous of North America.

The taxonomic history of these creatures has been rather tumultuous. Earlier, everyone was fixated on the fact that they were not a part of the enantiornithines group. However, later, proper examination of collected fossil material made it possible to classify the genus as a member of enantiornithines.

How do you pronounce 'Avisaurus'?

The word Avisaurus is pronounced as 'avi-sau-rus'. The type species name honors J. David Archibald, who discovered it. It is also known as the largest known enantiornithine (length-wise) of its era.

Avisaurus gloriae was discovered in the late Campanian Upper Two Medicine Formation of Glacier County, Montana, USA. It was named by Varricchio and Chiappe in 1995. But was later renamed by Scott Reid and his team.

What type of prehistoric flying bird was an Avisaurus?

This genus belongs to the enantiornithine family knows as Avisauridae.

This family has other members, such as the Soroavisaurus and Neuquenornis that lived in South America during the Late Cretaceous, approximately 70 million years ago, however they were separated by a branch of the Tethys Ocean.

Remains of Avisaurus archibaldi were recovered at the Hell Creek Formation, near Garfield County, in Montana, North America, in 1975 and it was one of the last enantiornithines.

The holotype or fossil collection at the University of California Museum of Paleontology is represented by a single fossil of a tarsometatarsus, which was used by Brett-Surman and Paul in 1985 for research.

In which geological period did the Avisaurus live?

Research studies conducted on fossils revealed that they lived during the Late Cretaceous age.

When did the Avisaurus become extinct?

The genus went extinct during the Cretaceous–Paleogene (K–Pg) mass extinction.

Where did an Avisaurus live?

Avisaurus fossil remains were discovered in the Hell Creek Formation of North America, indicating that the range of these pre-historic birds was in the North American region.

What was an Avisaurus' habitat?

They inhabited regions with humid climatic conditions. This included places such as forests, brooks, woods, ferns, shrubs, lakes, creeks, ponds, streams, low-lying swamps, river basins of the western shore of the Western Interior Seaway, arid upland areas which formed near the Cordilleran Overthrust Belt and later areas near the Rocky Mountains.

Who did an Avisaurus live with?

Paleontologists believe that they lived in solitude, or in a small-sized group, similar to several modern-day birds.

How long did an Avisaurus live?

The life span of A. gloriae is unknown.

How did they reproduce?

The reproductive manner of these pre-historic birds is considered to have been the same as that common to present-day birds. This means they most likely were oviparous and may have laid clutches of eggs in their nests. However, this theory has not yet been confirmed.

Avisaurus Fun Facts

What did an Avisaurus look like?

Initially, A. archibaldi was classified as a member of a new clade that represented non-avian theropod dinosaurs known as Avisauridae.

Even a study (conducted by Walker in 1981) of an isolated leg bone called tarsometatarsus (which is a fusion of tarsal and metatarsal structures) from a collection, indicated that it was a new clade. It is not known how many teeth they had.

The physical characteristics of this pre-historic creature can be compared to present-day birds as they had feathers, claws, beaks, and several other features seen in falcons and hawks today.

Varricchio and Chiappe described the physical characteristics, similar species, and history of the A. gloriae
*We've been unable to source an image of Avisaurus and have used an image of Mirarce eatoni instead. If you are able to provide us with a royalty-free image of Avisaurus, we would be happy to credit you. Please contact us at

How many bones did an Avisaurus have?

The exact number of bones present in this creature is unknown. This is because almost every fossil collection consists of only the remains of an individual's leg bones and a partial skeleton.

How did they communicate?

Communication between these animals that roamed the Earth 66 to 70.6 million years ago is still a mystery. Many scientists over the past decades have come up with several theories suggesting possible ways these animals communicated.

Some scientists put forth the theory of vocalizations and that they engaged in dialogue by producing calls, cracking sounds, body movements, and symbolic love calls during the mating season.

How big was an Avisaurus?

Curious about an Avisaurus size? Well, it grew up to 17.7-21.6 in (45-55 cm) in length and was the largest bird that lived during the Cretaceous era.

How fast could an Avisaurus move?

The speed rate of this 'bird-lizard' is unknown. However, some believe that they were excellent fliers and had swift movements.

How much did an Avisaurus weigh?

Adults weighed around 7-20.8 oz (200-590 g).

What were the male and female names of the species?

This species does not have gender-specific names for its male and female members, they are simply denoted as males and females.

What would you call a baby Avisaurus?

Since they laid eggs, a young baby Avisaurus can be referred to as a hatchling.

What did they eat?

Several research studies conducted on an Avisaurus' teeth and the diet of the Avisaurus revealed that it was primarily a carnivore and probably hunted mid-flight for small reptiles, mammals, and birds. Its hunting or foraging habits are similar to a falcon or hawk. However, some believe that it preyed more on small invertebrates and occasionally fed on plant material.

How aggressive were they?

They were territorial and aggressive towards any invaders or competition. Their behavior can be compared to any present-day large predatory bird. They avoided contact with any large carnivore dinosaur.

Did you know...

Titanis, a pre-historic bird that lived in South America grew up to 9.8 ft (3 m) in height and theories suggest that it would prey on animals as big as a horse.

How high could the Avisaurus fly?

Researchers speculate they had excellent flight skills and soared quite high.

What is the wingspan of the Avisaurus?

The wingspan of this pre-historic bird was 3.9 ft (1.2 m).

Here at Kidadl, we have carefully created lots of interesting family-friendly prehistoric animal facts for everyone to discover! Learn more about some other dinosaurs from our Peteinosaurus surprising facts and Thalassomedon fun facts for kids pages.

You can even occupy yourself at home by coloring in one of our free printable Avisaurus coloring pages.

Main image by Tomozsaurus.

Second image by Scott Hartman.

We Want Your Photos!
We Want Your Photos!

We Want Your Photos!

Do you have a photo you are happy to share that would improve this article?
Email your photos

More for You

See All

Written by Mellisa Nair

Bachelor of Arts specializing in Economics and English Literature

Mellisa Nair picture

Mellisa NairBachelor of Arts specializing in Economics and English Literature

Specializing in the creation of SEO-friendly content, Mellisa brings enthusiasm and expertise to our team. Her work in digital marketing and social media is complemented by her academic background in economics and English literature, as she holds a Bachelor's degree in these subjects from Wilson College Chowpatty, Mumbai. Mellisa's experience working with clients from various industries, including retail, education, and technology, reflects her ability to adapt her skills to different contexts and audiences.

Read full bio >