Wannanosaurus
"Wannan lizard"
- Lived
- 72 to 66 million years ago, Late Cretaceous
- Diet
- Herbivore
- Group
- Pachycephalosaurs
- Found in
- China
- Named by
- Hou 1977
Where its fossils were found
The evidence
Today
70 million years ago
Habitat
River deposits of the Xiaoyan Formation preserve Wannanosaurus and unnamed sauropods. Tracks from the same formation record small and medium-sized meat eaters.
Field notes
About Wannanosaurus
What it was like
Wannanosaurus was a tiny dome-headed dinosaur, one of the smallest known. It had a flat, thick skull roof instead of a high dome.
Its skeleton is partial, but it had a thickened skull roof like its bigger relatives, which suggests it too may have shoved or butted rivals.
Its world
It lived about 72 to 66 million years ago, in the Late Cretaceous, in what is now eastern China. Its fossil comes from the Xiaoyan Formation.
How it was found
Hou named Wannanosaurus in 1977, from a single find. The skull may belong to a young animal, which could explain its small size and flat head.
Field gallery
More views of Wannanosaurus
Scenes reconstructed from the available fossil evidence.
The evidence
The science behind Wannanosaurus
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- The partial skull has a thick, flat roof covered with small, closely packed bony bumps.
- The lower jaw carries teeth with serrated crowns.
- A strongly curved upper arm bone is a distinctive feature of Wannanosaurus.
Borrowed from relatives
- Prenocephale and Stegoceras guide the restoration of the missing front of the upper jaw.
- Homalocephale provides a comparison for the missing trunk and much of the tail and feet.
Still unknown
- Whether adults kept a flat skull roof or developed a dome.
- Its finger arrangement and complete foot anatomy.
- Its skin covering and color.
Often drawn wrong
- The known skull roof is flat, so a tall dome belongs to a hypothetical adult rather than the preserved animal.
Discovery timeline
- 1977Named itHou
- 2009RedescriptionButler & Zhao
- 2014Same rocksXing et al.
Key papers
The research behind what we know of Wannanosaurus
Named it
Described a small pachycephalosaur with a flat, bumpy skull roof, serrated teeth and partial limb bones.
A new primitive Pachycephalosauria from Anhui, China. Vertebrata PalAsiatica 15: 198-202
No link available
Redescription
Confirmed Wannanosaurus as a pachycephalosaur, identified its sharply curved upper arm bone and argued that the original specimens were probably young.
The small-bodied ornithischian dinosaurs Micropachycephalosaurus hongtuyanensis and Wannanosaurus yansiensis from the Late Cretaceous of China. Cretaceous Research 30: 63-77
Read the paper : The small-bodied ornithischian dinosaurs Micropachycephalosaurus hongtuyanensis and Wannanosaurus yansiensis from the Late Cretaceous of China (opens in a new tab)Same rocks
Described meat-eater tracks from river deposits in the Xiaoyan Formation, adding to the fauna known from Wannanosaurus and sauropod bones.
Upper Cretaceous dinosaur track assemblages and a new theropod ichnotaxon from Anhui Province, eastern China. Cretaceous Research 49: 190-204
Read the paper : Upper Cretaceous dinosaur track assemblages and a new theropod ichnotaxon from Anhui Province, eastern China (opens in a new tab)
Close relatives
Other members of Pachycephalosauria
Sources: Wikidata