Fun Achillesaurus Facts For Kids

Martha Martins
Jan 31, 2023 By Martha Martins
Originally Published on Oct 04, 2021
Edited by Luca Demetriou
Learn some interesting Achillesaurus facts!
Age: 3-18
Read time: 6.9 Min

Achillesaurus is a very interesting theropod dinosaur genus, whose fossil remains were found in 1995 by a team of the Museo Argentino de Ciencias Naturales Bernardino Rivadavia of Argentina, in the Bajo de la Carpa Formation, which is found in the Rio Negro Province of Argentina.

The team recovered a partial postcranial skeleton, that is, parts of its skeleton, like some of its tail vertebrae, were found but the skull was missing.

They were also discovered in partial articulation, which means that the bones of the specimen were placed almost in their proper positions.

It was found that this dinosaur would have been alive during the Santonian age of the Late Cretaceous.

These bones were only named and described as a new genus of dinosaurs in 2007 by Agustín G. Martinelli and Ezequiel I. Vera. The genus consists of a single species, which is also its type species and is named Achillesaurus manazzonei.

In their research, Agustín G. Martinelli and Ezequiel I. Vera found this new genus to be a basal member of the family Alvarezsauridae because it was found to have similar features as the type genus of that family, Alvarezsaurus, which was also found in Argentina from the same locality, that is, the Bajo de la Carpa Formation.

However, Apesteguía, along with others, recently proposed that the new alvarezsaurid Achillesaurus and Alvarezsaurus might be the same dinosaurs, as they only have minor differences between them.

Keep reading to find out more amazing facts about this fascinating member of Dinosauria!

If you want to know more about other cool dinosaurs, check out our Yandusaurus interesting facts for kids and Valdoraptor interesting facts for kids pages.

Achillesaurus Interesting Facts

How do you pronounce 'Achillesaurus'?

The name of this new alvarezsaurid was given by Agustín G. Martinelli and Ezequiel I. Vera and is phonetically pronounced as 'Ah-kil-le-sore-us'.

What type of dinosaur was an Achillesaurus?

Achillesaurus manazzonei was a member of the large clade Theropoda and was classified by Martinelli and Vera as a new alvarezsaurid based on the fact that much of the structure of its bones resembled that of Alvarezsaurids.

Members of Alvarezsauridae had an insectivorous or carnivorous diet, short forelimbs, and strong breast and arm muscles.

These muscles, complete with their bird-like hands, were thought to have facilitated easier digging for insect nests. Alvarezsauridae is considered to be a basal group in Maniraptora, and are thought to have been related to the members of Ornithomimosauria.

Achillesaurus was also found to share many features with Alvarezsaurus, which was also found not far away in the same locality, that is, in the Bajo de la Carpa Formation in Argentina, and would have also lived during the Santonian age of the Late Cretaceous.

Alvarezsaurus is the most basal member of Alvarezsauridae, as the family was formed to contain this dinosaur, and it is also the type genus for it.

The relationship between Achillesaurus and Alvarezsaurus is not clear but recently, Apesteguía suggested that they could have been the same dinosaur.

In which geological period did the Achillesaurus roam the earth?

The holotype specimen of this alvarezsaurid was found in the rock strata in the Bajo de la Carpa Formation that corresponded to the Upper Cretaceous, which means that it would have been alive during the Santonian age of the Late Cretaceous period in modern-day Argentina. Thus, they would have walked on Earth about 85 million years ago.

When did the Ahillesaurus become extinct?

Since they lived during one of the last ages, that is, the Santonian age, of the Late Cretaceous period, they would have died off in the Cretaceous-Paleogene extinction event that occurred almost 66 million years ago.

Where did an Achillesaurus live?

This alvarezsaurid dinosaur had lived in what is now known as Argentina as fossil remains of its holotype specimen were recovered from the Bajo de la Carpa Formation, which is situated in the Rio Negro Province of Argentina.

What was an Achillesaurus' habitat?

Research into the deposits of the Bajo de la Carpa Formation of Argentina determined that it would have been a terrestrial environment, and there would have been many rivers and water bodies in the region.

Who did an Achillesaurus live with?

Achillesaurus manazzonei is thought to have been a solitary animal and would have lived independent of other Alvarezsaurids.

It would have coexisted with other members of Dinosauria that would have been found in the same location, such as Alvarezsaurus, another alvarezsaurid that lived during the Santonian age of the Late Cretaceous, and whose specimen was found in the Bajo de la Carpa Formation in Argentina.

How long did an Achillesaurus live?

The lifespan of this new alvarezsaurid is not currently known due to a lack of research.

How did they reproduce?

These dinosaurs, like all other members of Dinosauria, were oviparous and laid eggs instead of giving birth to live young like mammals. 

Achillesaurus Fun Facts

What did an Achillesaurus look like?

The Achillesaurus skeleton recovered from Bajo de la Carpa Formation consisted of postcranial remains of a single specimen, which included some tail vertebrae, a sacral vertebra, many bones from its leg, which are thought to have made up diagnostic features for this new alvarezsaurid genus.

This dinosaur could have been covered with feathers and would have been similar to Alvarezsaurus in appearance as it had long legs and a long tail.

Achillesaurus was, at first, thought to have been twice the size of Alvarezsaurus, but more research concluded that the bones of the latter were of a juvenile specimen.

Achillesaurus was a large alvarezsaurid dinosaur with long legs.
*We've been unable to source an image of Achillesaurus and have used an image of Alvarezsaurus instead. If you are able to provide us with a royalty-free image of Achillesaurus, we would be happy to credit you. Please contact us at

How many bones did an Achillesaurus have?

The total number of bones this new alvarezsaurid would have had is currently unknown based on the fact that only a partial skeleton of this dinosaur has been found from the Bajo de la Carpa Formation, and an Achillesaurus skull has still not been discovered.

How did they communicate?

All members of Dinosauria are thought to have communicated using vocalizations or body language, but the specific way this theropod communicated is not currently known.

How big was an Achillesaurus?

Although the exact size of this theropod is not known, all Alvarezsaurids have been estimated to have had a body length in the range of 20-98 in (0.5-2.5 m). Alvarezsaurus, which also lived during the Late Cretaceous and with whom Achillesaurus manazzonei had an unspecified relationship, was 4.6 ft (1.4 m) in length.

How fast could an Achillesaurus move?

Since Alvarezsaurids are thought to have been fast bipedal animals due to their long hind limbs, Achillesmanazzonei would have also been an agile runner.

How much did an Achillesaurus weigh?

The weight of this genus of dinosaurs is not currently known due to a lack of research and evidence.

What were the male and female names of the species?

There were no specific names for the males and females of this species and genus.

What would you call a baby Achillesaurus?

A baby dinosaur of this kind would have been called a hatchling.

What did they eat?

The diet of Alvarezsaurids has been an issue of debate since not much is known about their teeth. While it was first thought that they would have had a diet that consisted exclusively of insects, evidence was found that suggested that these dinosaurs fed on dinosaur eggs as well.

How aggressive were they?

Although fairly small in size, they could have been aggressive towards any animal that would have invaded their territory.

Did you know...

Members of Alvarezsauridae were once thought to have been flightless birds of the Mesozoic Era based on the many features it shared with birds and were also thought to have been a part of Avialae, which is a clade that consists of all birds.

However, new research has shown that those traits in Alvarezsaurids were evolved independently, and they were not related to birds or flying dinosaurs.

Was the Achillesaurus a theropod?

Yes, Achillesaurus manazzonei belonged to Theropoda. Theropoda consists of a wide variety of dinosaurs, including the ancestors of birds, as we see them today.

How was the Achillesaurus named?

Achillesaurus was named by Agustín G. Martinelli and Ezequiel I. Vera, for the Achilles' heel, which was the weakest point of Achilles from the book 'Iliad' by Homer, as diagnostic features were found in that part of the holotype specimen. Thus, the name translates to 'Achilles lizard'.

The specific name is a reference to Prof. Rafael Manazzone, who helped in the research and discovery of this theropod.

Here at Kidadl, we have carefully created lots of interesting family-friendly dinosaur facts for everyone to discover! For more relatable content, check out these Camarillasaurus facts and Suuwassea facts for kids.

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

Image one by Levi bernardo.

Image two by Karkemish.

Achillesaurus Facts

What Did They Prey On?

Ants, termites, dinosaur eggs

what Type of Animal were they?


Average Litter Size?


What Did They Look Like?

Large-sized with long limbs

How Much Did They Weigh?


Skin Type

Scales or feathers

How Long Were They?

20-98 in (0.5-2.5 m)

How Tall Were They?





Dinosauria, Saurischia, Theropoda





Scientific Name

Achillesaurus manazzonei

What Were Their Main Threats?

Natural disasters

What Habitat Did They Live In?

Terrestrial environment

Where Did They Live?

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Written by Martha Martins

Bachelor of Arts specializing in Linguistics

Martha Martins picture

Martha MartinsBachelor of Arts specializing in Linguistics

Martha is a full-time creative writer, content strategist, and aspiring screenwriter who communicates complex thoughts and ideas effectively. She has completed her Bachelor's in Linguistics from Nasarawa State University. As an enthusiast of public relations and communication, Martha is well-prepared to substantially impact your organization as your next content writer and strategist. Her dedication to her craft and commitment to delivering high-quality work enables her to create compelling content that resonates with audiences.

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