Isaberrysaura
- Lived
- 171 to 169 million years ago, Middle Jurassic
- Diet
- Herbivore
- Group
- Stegosaurs, Huayangosauridae
- Found in
- Argentina
- Named by
- Salgado et al. 2017
Where its fossils were found
The evidence
Today
170 million years ago
Habitat
It probably fed among cycads on land near a coastal delta in what is now Argentina. Its body was buried in mud deposited where the delta met the sea.
Field notes
About Isaberrysaura
What it was like
Isaberrysaura was an early relative of the stegosaurs, a plant eater with a nearly complete skull. Its stomach area held preserved seeds, which show what it had eaten.
Its world
It lived in the Middle Jurassic, in what is now Argentina. It comes from the Los Molles Formation, which formed in the sea, so its body was probably washed out from the coast. It is the first stegosaur relative known from South America.
How it was found
Salgado and colleagues named Isaberrysaura in 2017. It was first described as an early ornithopod, but later studies moved it close to Huayangosaurus.
Field gallery
More views of Isaberrysaura
Scenes reconstructed from the available fossil evidence.
1 of 3
The evidence
The science behind Isaberrysaura
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- A nearly complete skull has a long snout with curved front teeth and leaf-shaped cheek teeth.
- A partial skeleton preserves parts of the neck, back, hips and tail.
- Seeds preserved inside its belly include cycad seeds with their fleshy outer coats still attached.
Borrowed from relatives
- Its missing limbs and body outline are restored by comparison with early stegosaurs such as Huayangosaurus.
Still unknown
- Whether it carried plates or spikes, and how they were arranged.
- Its skin covering and color.
- Whether swallowed seeds could pass through its gut and sprout.
Discovery timeline
- 2017Named itSalgado et al.
- 2023Family treeRaven et al.
- 2025Family treeSánchez-Fenollosa & Cobos
Key papers
The research behind what we know of Isaberrysaura
Named it
Described the skull and preserved belly contents, revealing a plant eater that swallowed cycad seeds.
A new primitive Neornithischian dinosaur from the Jurassic of Patagonia with gut contents. Scientific Reports 7
Read the paper : A new primitive Neornithischian dinosaur from the Jurassic of Patagonia with gut contents (opens in a new tab)Family tree
Placed Isaberrysaura among early stegosaurs, close to Huayangosaurus, by comparing skull and tooth features.
The phylogenetic relationships and evolutionary history of the armoured dinosaurs (Ornithischia: Thyreophora). Journal of Systematic Palaeontology 21
Read the paper : The phylogenetic relationships and evolutionary history of the armoured dinosaurs (Ornithischia: Thyreophora) (opens in a new tab)Family tree
A new stegosaur skull comparison supported placing Isaberrysaura in Huayangosauridae.
New insights into the phylogeny and skull evolution of stegosaurian dinosaurs: An extraordinary cranium from the European Late Jurassic (Dinosauria: Stegosauria). Vertebrate Zoology 75: 165-189
Read the paper : New insights into the phylogeny and skull evolution of stegosaurian dinosaurs: An extraordinary cranium from the European Late Jurassic (Dinosauria: Stegosauria) (opens in a new tab)
Close relatives
Other members of Huayangosauridae
Sources: Wikidata