Ahshislesaurus
Type species Ahshislesaurus wimani
- Lived
- 84 to 72 million years ago, Late Cretaceous
- Diet
- Herbivore
- Group
- Ornithopods, Hadrosauridae
- Found in
- United States
- Named by
- Dalman et al. 2025
Where its fossils were found
The evidence
Today
80 million years ago
Habitat
Rivers and wet lowlands in what is now New Mexico. Dinosaurs from these rocks include Bistahieversor, Pentaceratops and Parasaurolophus.
Field notes
About Ahshislesaurus
What it was like
Ahshislesaurus was a duck-billed plant eater, a relative of Gryposaurus and Kritosaurus. It is known from part of a skull and a few neck bones. Like other duckbills, it had a broad beak and many rows of grinding teeth.
Its world
It lived in the Late Cretaceous in what is now New Mexico. Its bones come from the Kirtland Formation, a land of rivers and swamps where it shared the land with the tyrannosaur Bistahieversor, the horned Pentaceratops and the crested Parasaurolophus.
How it was found
Its skull was dug up long before it was named, and for years scientists debated whether it belonged to Kritosaurus. Dalman and colleagues gave it its own name in 2025. The type species is Ahshislesaurus wimani.
Field gallery
More views of Ahshislesaurus
Scenes reconstructed from the available fossil evidence.
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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 Ahshislesaurus.
The evidence
The science behind Ahshislesaurus
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- The original fossil includes an incomplete skull, lower jaw bones and a short series of neck vertebrae.
- Its skull has a low, flat roof, like that of Naashoibitosaurus.
Borrowed from relatives
- The missing body is restored using other duckbills, such as Edmontosaurus, for the trunk, limbs and long tail.
Still unknown
- Whether the additional skeleton and limb bones from the same rocks belong to Ahshislesaurus.
- Its skin color and pattern.
- How its head changed as it grew.
Discovery timeline
- 2010Same rocksCarr & Williamson
- 2013Close relativePrieto-Márquez
- 2025Named itDalman et al.
Key papers
The research behind what we know of Ahshislesaurus
Same rocks
Named Bistahieversor, a deep-snouted predator from the Kirtland Formation, and examined how deep snouts evolved in tyrannosaur relatives.
Bistahieversor sealeyi, gen. et sp. nov., a new tyrannosauroid from New Mexico and the origin of deep snouts in Tyrannosauroidea. Journal of Vertebrate Paleontology 30: 1-16
Read the paper : Bistahieversor sealeyi, gen. et sp. nov., a new tyrannosauroid from New Mexico and the origin of deep snouts in Tyrannosauroidea (opens in a new tab)Close relative
Redescribed Kritosaurus and compared the skulls and relationships of duckbills with solid snout crests.
Skeletal morphology ofKritosaurus navajovius(Dinosauria: Hadrosauridae) from the Late Cretaceous of the North American south-west, with an evaluation of the phylogenetic systematics and biogeography of Kritosaurini. Journal of Systematic Palaeontology 12: 133-175
Read the paper : Skeletal morphology ofKritosaurus navajovius(Dinosauria: Hadrosauridae) from the Late Cretaceous of the North American south-west, with an evaluation of the phylogenetic systematics and biogeography of Kritosaurini (opens in a new tab)Named it
Separated an old skull from Kritosaurus and named a flat-headed duckbill with similarities to Naashoibitosaurus.
A new saurolophine hadrosaurid (Ornithischia: Hadrosauridae) from the Upper Cretaceous (Campanian) Hunter Wash Member, Kirtland Formation, San Juan Basin, New Mexico. Fossil Record 11. New Mexico Museum of Natural History and Science Bulletin 101.
No link available
Close relatives
Other members of Hadrosauridae
Sources: Wikidata