Chirostenotes
KYE-roh-sten-OH-teez
"narrow hands"
- Lived
- 84 to 66 million years ago, Late Cretaceous
- Diet
- Omnivore
- Length
- about 1.7 m (6 ft)
- Group
- Theropods, Caenagnathidae
- Found in
- United States and Canada
- Named by
- Gilmore 1924
Size comparison
To scale
Scale in metersOutline: typical theropod shape
Where its fossils were found
The evidence
Today
75 million years ago
Habitat
Meandering rivers crossed a low floodplain with conifers and ferns. Gorgosaurus, Stegoceras and Saurornitholestes lived in the same region.
Field notes
About Chirostenotes
What it was like
Chirostenotes was a feathered, beaked dinosaur from the oviraptor family, about 1.7 meters (6 feet) long. It had long, slender fingers and long legs, and a toothless beak.
It probably ate plants, eggs and small animals, but no one knows for sure.
Its world
It lived in the Late Cretaceous in what is now Alberta, Canada. Its bones come from the Dinosaur Park Formation, where it shared the land with the tyrannosaurs Gorgosaurus and Daspletosaurus, the dome-headed Stegoceras and the small hunters Troodon and Saurornitholestes.
How it was found
Gilmore named Chirostenotes in 1924 from a pair of hands. For decades its hands, feet and jaws were found separately and given different names, until better skeletons showed they came from the same kind of animal.
Field gallery
More views of Chirostenotes
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 Chirostenotes.
The evidence
The science behind Chirostenotes
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- The first fossils were slender hands with a strongly curved thumb claw and a much straighter claw on the next finger.
- A partial skeleton preserves a toothless lower jaw with an upturned tip, neck and tail vertebrae, and parts of the hindlimbs.
- Foot bones show a small inner toe beside the main weight-bearing toes.
Borrowed from relatives
- Anzu provides a comparison for the missing upper face, trunk and tail.
- Feathers on the body and arms are inferred from feathered oviraptorosaurs such as Caudipteryx.
Still unknown
- Whether it had a head crest, and what that crest looked like.
- Its feather colors and the shape of any tail fan.
- Exactly which foods it ate.
Often drawn wrong
- Giving it the tall crescent-shaped crest of Anzu treats a relative's feature as its own.
- Its hand claws differed in shape rather than forming a row of identical hooks.
Discovery timeline
- 1924Named itGilmore
- 2020New findFunston & Currie
- 2020Family treeFunston
Key papers
The research behind what we know of Chirostenotes
Named it
Named Chirostenotes from a pair of slender hands with distinctive claws.
A new Coelurid dinosaur from the Belly River Cretaceous of Alberta.
Read the paper : A new Coelurid dinosaur from the Belly River Cretaceous of Alberta (opens in a new tab)New find
A skeleton with both jaws and body bones linked the upturned lower beak to Chirostenotes and showed that the animal was nearing full size.
New material ofChirostenotes pergracilis(Theropoda, Oviraptorosauria) from the Campanian Dinosaur Park Formation of Alberta, Canada. Historical Biology 33: 1671-1685
Read the paper : New material ofChirostenotes pergracilis(Theropoda, Oviraptorosauria) from the Campanian Dinosaur Park Formation of Alberta, Canada (opens in a new tab)Family tree
Compared bones and growth marks to distinguish Chirostenotes, Citipes and Caenagnathus as separate animals with different adult sizes.
Caenagnathids of the Dinosaur Park Formation (Campanian) of Alberta, Canada: anatomy, osteohistology, taxonomy, and evolution. Vertebrate Anatomy Morphology Palaeontology 8: 105-153
Read the paper : Caenagnathids of the Dinosaur Park Formation (Campanian) of Alberta, Canada: anatomy, osteohistology, taxonomy, and evolution (opens in a new tab)
Close relatives
Other members of Caenagnathidae
Sources: Wikidata