Leptorhynchos
"slender beak"
Type species Leptorhynchos gaddisi
- Lived
- 84 to 72 million years ago, Late Cretaceous
- Diet
- Omnivore
- Group
- Theropods, Caenagnathidae
- Found in
- United States
- Named by
- Longrich et al. 2013
Where its fossils were found
The evidence
Today
80 million years ago
Habitat
It lived on a coastal floodplain in what is now Texas. Other dinosaurs recorded from the Aguja Formation include Stegoceras and Edmontonia.
Field notes
About Leptorhynchos
What it was like
Leptorhynchos was a small feathered dinosaur from the caenagnathids, toothless relatives of Oviraptor. It is known from lower jaws that end in an upturned beak.
Its world
It lived in the Late Cretaceous in what is now Texas, in the United States. Its jaws come from the Aguja Formation, where it shared the land with the dome-headed Stegoceras and the armored Edmontonia.
How it was found
Longrich and colleagues named Leptorhynchos in 2013. A second species from Canada was first placed in it, but has since been moved to a genus of its own, Citipes.
Field gallery
More views of Leptorhynchos
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 Leptorhynchos.
The evidence
The science behind Leptorhynchos
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- The original specimen preserves the fused front portions of the lower jaws, with the back of the jaw broken away.
- The jaws are toothless, with smooth edges that supported a beak.
- The beak tip turns upward and is narrow when viewed from above. The lower front of the jaw is rounded rather than squared off as in Citipes.
Borrowed from relatives
- The upper face, neck, body, legs and tail are restored by comparison with Anzu, a caenagnathid known from much more of its skeleton.
- The hands and feet are restored by comparison with Chirostenotes.
Still unknown
- Whether tail and foot bones assigned to it from the same rocks, mainly on their size, really belong to Leptorhynchos. The naming paper itself treats a large hand claw once linked with it as doubtful.
- The shape of its upper beak and skull.
- Exactly what it ate, and the pattern and color of its feathers.
Discovery timeline
- 2013Named itLongrich et al.
- 2014Close relativeLamanna et al.
- 2015Family treeFunston, Currie & Burns
- 2020Family treeFunston
Key papers
The research behind what we know of Leptorhynchos
Named it
Named Leptorhynchos from small, deep, toothless jaws and suggested that differences in beak shape helped caenagnathids feed in different ways.
Caenagnathidae from the Upper Campanian Aguja Formation of West Texas, and a Revision of the Caenagnathinae. Bulletin of the Peabody Museum of Natural History 54: 23-49
Read the paper : Caenagnathidae from the Upper Campanian Aguja Formation of West Texas, and a Revision of the Caenagnathinae (opens in a new tab)Close relative
Named Anzu from partial skeletons that show the skull, neck, arms, hips, legs and tail of a large caenagnathid.
A New Large-Bodied Oviraptorosaurian Theropod Dinosaur from the Latest Cretaceous of Western North America. PLoS ONE 9: e92022
Read the paper : A New Large-Bodied Oviraptorosaurian Theropod Dinosaur from the Latest Cretaceous of Western North America (opens in a new tab)Family tree
Described leg and foot bones then assigned to Leptorhynchos elegans, now Citipes, and compared their anatomy with Elmisaurus.
New elmisaurine specimens from North America and their relationship to the Mongolian Elmisaurus rarus. Acta Palaeontologica Polonica
Read the paper : New elmisaurine specimens from North America and their relationship to the Mongolian Elmisaurus rarus. (opens in a new tab)Family tree
Separated Citipes from Leptorhynchos and reorganized the caenagnathids of the Dinosaur Park Formation using anatomy and bone growth.
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