Bagaraatan
"small predator"
Type species Bagaraatan ostromi
- Lived
- 72 to 66 million years ago, Late Cretaceous
- Diet
- Carnivore
- Group
- Theropods, Tyrannosauridae
- Found in
- Mongolia
- Named by
- Osmólska 1996
Where its fossils were found
The evidence
Today
70 million years ago
Habitat
Rivers crossed its home in the Nemegt Formation. Tarbosaurus, Gallimimus and Deinocheirus lived in the region.
Field notes
About Bagaraatan
What it was like
Bagaraatan was a small two-legged predator known from a lower jaw, hip bones and parts of a leg. It may have been an early relative of the tyrannosaurs, but its place is debated, and some scientists think its bones come from more than one animal.
Its world
It lived about 72 to 66 million years ago, at the end of the Late Cretaceous, in what is now Mongolia. Its bones come from the Nemegt Formation, a land of rivers where it shared the land with the huge predator Tarbosaurus, the ostrich-like Gallimimus and the giant Deinocheirus.
How it was found
Osmólska named it in 1996. The type species is Bagaraatan ostromi. Its name comes from Mongolian words.
Field gallery
More views of Bagaraatan
Scenes reconstructed from the available fossil evidence.
Lived alongside
Found in the same rock formations
A rock formation can hold fossils laid down millions of years apart, so not every animal here met Bagaraatan.
The evidence
The science behind Bagaraatan
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- The lower jaw, neck and tail vertebrae, hip bones and a toe bone belong to a young tyrannosaur.
- Leg bones once assigned to Bagaraatan belong to a different, beaked theropod.
Borrowed from relatives
- Missing parts are restored by comparison with young tyrannosaurs such as Tarbosaurus and Tyrannosaurus.
Still unknown
- Whether Bagaraatan is a separate species or a youngster of an already named tyrannosaur.
- Its adult size and appearance.
- Its skin covering and color.
Discovery timeline
- 1996Named itOsmólska
- 2016Family treeBrusatte & Carr
- 2024RedescriptionSłowiak, Brusatte & Szczygielski
Key papers
The research behind what we know of Bagaraatan
Named it
Named Bagaraatan from an incomplete skeleton with an unusual mix of jaw, hip and leg features.
An unusual theropod dinosaur from the Late Cretaceous Nemegt Formation of Mongolia. Acta Palaeontologica Polonica 41: 1-38
No link available
Family tree
Excluded Bagaraatan from its tyrannosaur family tree because the original skeleton appeared to mix bones from different animals.
The phylogeny and evolutionary history of tyrannosauroid dinosaurs. Scientific Reports 6
Read the paper : The phylogeny and evolutionary history of tyrannosauroid dinosaurs (opens in a new tab)Redescription
Separated unrelated bones from the original material and identified the remaining skeleton as a juvenile tyrannosaur.
Reassessment of the enigmatic Late Cretaceous theropod dinosaur, Bagaraatan ostromi. Zoological Journal of the Linnean Society 202
Read the paper : Reassessment of the enigmatic Late Cretaceous theropod dinosaur, Bagaraatan ostromi (opens in a new tab)
Close relatives
Other members of Tyrannosauridae
Sources: Wikidata