Alvarezsaurus
Alvarezsaurus was a tiny, fast-running dinosaur that lived in Argentina about 86 to 83 million years ago. It had a long tail and probably used its sharp claws to dig for insects. Scientists think it was one of the earliest members of a weird group of dinosaurs with strong, short arms.13
When did it live?
How big was it?
How big was Alvarezsaurus compared to YOU?
Just maths in your browser. Nothing is saved or sent anywhere.
Fun facts
Alvarezsaurus was named after Don Gregorio Alvarez, an Argentine historian, not after a dinosaur scientist.1
Its third toe bone (metatarsal III) was the longest, and its fourth toe bone was unusually long too.1
Unlike many of its later relatives, Alvarezsaurus did not have its ankle bones (astragalus and calcaneum) fused together.1
The shoulder blade of Alvarezsaurus was curved and smaller than that of later alvarezsaurids like Mononykus.1
Its tail vertebrae had sharp undersides and triangular side projections, a feature shared with other alvarezsaurids.1
Alvarezsaurus is considered a basal (early) member of the alvarezsaurid family, which includes dinosaurs with strong, short arms and big claws.1
Most asked questions about Alvarezsaurus
?How big was Alvarezsaurus?
Alvarezsaurus was small, about 1 to 1.4 metres (3.3 to 4.6 feet) long and weighed around 3 kilograms (6.6 pounds).1
?What did Alvarezsaurus eat?
It may have eaten insects. Its sharp claws and strong arms suggest it dug into termite or ant nests, though scientists are not completely sure.12
?Could Alvarezsaurus run fast?
Yes, its leg structure suggests it was a fast runner. It had long legs and a long tail for balance.12
?Did Alvarezsaurus have feathers?
No direct feather fossils are known for Alvarezsaurus, but a close relative, Shuvuuia, had downy, feather-like coverings, so it likely had feathers too.2
?When did Alvarezsaurus live?
It lived during the Late Cretaceous, about 86 to 83 million years ago, in what is now Argentina.1
?Was Alvarezsaurus a dinosaur?
Yes, Alvarezsaurus was a small theropod dinosaur, part of the alvarezsaurid family.1
Ask Rex about Alvarezsaurus
Rex only answers questions about this page. 3 questions a day.
Rex is an AI and can make mistakes. He runs on servers in the EU and questions are never saved. Never type your name or other personal things.
For dino experts
- Scientific name
- Alvarezsaurus
- Named by
- Bonaparte 19913
- Group
- Odd feathered dinos
- Family / clade
- Alvarezsauridae3
- Classification
- Theropoda > Alvarezsauridae3
- Age of the rocks
- 86 to 84 million years (Santonian)3
- Rock formations
- Bajo de la Carpa3
- Countries
- Argentina3
- Fossil records
- 1 in the Paleobiology Database3
- Discovery
- Alvarezsaurus was named by Argentine paleontologist José Bonaparte in 1991. The first fossils were found in the Bajo de la Carpa Formation in Argentina.13
- Still debated
- Scientists are not sure whether Alvarezsaurus was more closely related to birds or to other non‑bird dinosaurs. Some studies place it with early birds, but others keep it among the theropod dinosaurs.1
Where the facts come from
- Alvarezsaurus (en.wikipedia.org)
- Alvarezsauridae (en.wikipedia.org)
- Alvarezsaurus 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.
Rex is hungry! Dino Wiki is a dad's project for his dino-loving son, free with no ads. Grown-ups can feed Rex a snack to help keep it online.Feed Rex
Therizinosaurus
Oviraptor
Chirostenotes
Citipes
Leptorhynchos
Avimimus
Triceratops
Velociraptor
Spinosaurus
Ankylosaurus
Parasaurolophus