Anodontosaurus
"toothless lizard"
- Lived
- 84 to 66 million years ago, Late Cretaceous
- Diet
- Herbivore
- Group
- Ankylosaurs, Ankylosauridae
- Found in
- Canada
- Named by
- Sternberg 1929
Where its fossils were found
The evidence
Today
75 million years ago
Habitat
Its world included a coastal plain with wet ground and better-drained areas as the shoreline shifted. Neighbors included Edmontonia, Hypacrosaurus and Ornithomimus.
Field notes
About Anodontosaurus
What it was like
Anodontosaurus was a club-tailed ankylosaur, low and wide, with bony armor across its back and a heavy club at the end of its tail. Its tail club was flattened and ended in pointed knobs.
Its name means "toothless lizard" because the first skull was found without its teeth, though in life it had small, leaf-shaped teeth like other ankylosaurs.
Its world
It lived in the Late Cretaceous in what is now Alberta, Canada. Its bones come from the Horseshoe Canyon and Dinosaur Park formations, where it shared the land with Euoplocephalus, the armored Edmontonia and the ostrich-like Ornithomimus and Struthiomimus.
How it was found
Sternberg named Anodontosaurus in 1929. For decades it was treated as a form of Euoplocephalus, until a study of its tail club and armor showed it deserved its own genus again. About 13 finds are now known.
Field gallery
More views of Anodontosaurus
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 Anodontosaurus.
The evidence
The science behind Anodontosaurus
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- Skulls have small bony plates behind the eyes, around the bases of the skull horns.
- Neck armor has small bony plates surrounding the larger plates.
- Tail clubs assigned to Anodontosaurus are wider than they are long, with bluntly pointed sides.
Borrowed from relatives
- Missing parts of the body are restored using Euoplocephalus and Scolosaurus, close relatives with more complete skeletons.
- Scaly skin between the armor plates follows preserved skin in Scolosaurus.
Still unknown
- The complete arrangement of armor across its back.
- Its color.
- How its tail club changed as it grew.
Discovery timeline
- 1929Named itSternberg
- 2013RedescriptionArbour & Currie
- 2015Family treeArbour & Currie
Key papers
The research behind what we know of Anodontosaurus
Named it
Named Anodontosaurus from an armored dinosaur skeleton found in Alberta.
A toothless armoured dinosaur from the Upper Cretaceous of Alberta.
Read the paper : A toothless armoured dinosaur from the Upper Cretaceous of Alberta (opens in a new tab)Redescription
Restored Anodontosaurus as a separate genus using its skull plates, neck armor and broad, pointed tail club.
Euoplocephalus tutus and the Diversity of Ankylosaurid Dinosaurs in the Late Cretaceous of Alberta, Canada, and Montana, USA. PLoS ONE 8: e62421
Read the paper : Euoplocephalus tutus and the Diversity of Ankylosaurid Dinosaurs in the Late Cretaceous of Alberta, Canada, and Montana, USA (opens in a new tab)Family tree
Compared ankylosaurid species to revise their family tree and trace their spread between Asia and North America.
Systematics, phylogeny and palaeobiogeography of the ankylosaurid dinosaurs. Journal of Systematic Palaeontology 14: 385-444
Read the paper : Systematics, phylogeny and palaeobiogeography of the ankylosaurid dinosaurs (opens in a new tab)
Close relatives
Other members of Ankylosauridae
Sources: Wikidata