Thyreosaurus
"shield lizard"
Type species Thyreosaurus atlasicus
- Lived
- 168 to 162 million years ago, Middle Jurassic
- Diet
- Herbivore
- Group
- Stegosaurs, Stegosauridae
- Found in
- Morocco
- Named by
- Zafaty et al. 2024
Where its fossils were found
The evidence
Today
165 million years ago
Habitat
A continental landscape in what is now Morocco. Spicomellus and Adratiklit also lived in the El Mers III Formation.
Field notes
About Thyreosaurus
What it was like
Thyreosaurus was a stegosaur, a plant eater with bony plates or spikes along its back. It is known from part of one skeleton, including back bones, ribs and pieces of armor.
Its world
It lived in the Middle Jurassic, in what is now Morocco. It comes from the El Mers III Formation, where it shared the land with the spiky early ankylosaur Spicomellus and the stegosaur Adratiklit.
How it was found
Zafaty and colleagues named Thyreosaurus in 2024. The type species is Thyreosaurus atlasicus, after the mountains where it was found.
Field gallery
More views of Thyreosaurus
Scenes reconstructed from the available fossil evidence.
1 of 3
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 Thyreosaurus.
The evidence
The science behind Thyreosaurus
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- Back bones and ribs belong to a partial skeleton with a comparatively narrow ribcage.
- The armor includes thick bony shields with oval to rectangular outlines.
- Different textures on opposite sides of the shields suggest they lay low against the body.
Borrowed from relatives
- The small, narrow, beaked head and missing limbs are restored by comparison with Stegosaurus.
- Other stegosaurs provide a model for compact front feet and blunt, hoof-like hind toes.
Still unknown
- Exactly where its armor sat, and how many shields it carried.
- The shape of its skull and any weapons on its tail.
- Its color and skin covering.
Discovery timeline
- 2010PostureSenter
- 2015Close relativeMaidment, Brassey & Barrett
- 2024Named itZafaty et al.
Key papers
The research behind what we know of Thyreosaurus
Posture
Showed that stegosaur hand bones fitted into a compact, upright half-tube rather than a spreading fan.
Evidence for a Sauropod-Like Metacarpal Configuration in Stegosaurian Dinosaurs. Acta Palaeontologica Polonica 55: 427-432
Read the paper : Evidence for a Sauropod-Like Metacarpal Configuration in Stegosaurian Dinosaurs (opens in a new tab)Close relative
Described a nearly complete Stegosaurus skeleton, providing comparisons for the missing limbs and body of Thyreosaurus.
The Postcranial Skeleton of an Exceptionally Complete Individual of the Plated Dinosaur Stegosaurus stenops (Dinosauria: Thyreophora) from the Upper Jurassic Morrison Formation of Wyoming, U.S.A. PLOS ONE 10: e0138352
Read the paper : The Postcranial Skeleton of an Exceptionally Complete Individual of the Plated Dinosaur Stegosaurus stenops (Dinosauria: Thyreophora) from the Upper Jurassic Morrison Formation of Wyoming, U.S.A. (opens in a new tab)Named it
Described a partial stegosaur skeleton with unusually thick bony shields that may have lain low against its body.
A new stegosaurian dinosaur (Ornithischia: Thyreophora) with a remarkable dermal armour from the Middle Jurassic of North Africa. Gondwana Research 131: 344-362
Read the paper : A new stegosaurian dinosaur (Ornithischia: Thyreophora) with a remarkable dermal armour from the Middle Jurassic of North Africa (opens in a new tab)
Close relatives
Other members of Stegosauridae
Sources: Wikidata