Alaskacephale
"Alaska head"
- Lived
- 72 to 66 million years ago, Late Cretaceous
- Diet
- Herbivore
- Group
- Pachycephalosaurs, Pachycephalosauridae
- Found in
- United States
- Named by
- Sullivan 2006
Where its fossils were found
The evidence
Today
70 million years ago
Habitat
A forested Arctic floodplain had rivers, wet ground and long, dark winters. The Prince Creek Formation also preserves Pachyrhinosaurus, Edmontosaurus and Nanuqsaurus.
Field notes
About Alaskacephale
What it was like
Alaskacephale was a bone-headed dinosaur, a two-legged plant eater with a thick, domed skull. It is known from a single bone from the back of the skull, covered in bony knobs.
Its world
It lived about 72 to 66 million years ago, at the end of the Late Cretaceous, in what is now northern Alaska. The region lay far north even then, with dark winters. Its bones come from the Prince Creek Formation, where it shared the land with the horned Pachyrhinosaurus, the duckbill Edmontosaurus and the small tyrannosaur Nanuqsaurus.
How it was found
Sullivan named Alaskacephale in 2006 from one find. It is one of the few bone-headed dinosaurs known from the far north.
Field gallery
More views of Alaskacephale
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 Alaskacephale.
The evidence
The science behind Alaskacephale
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- A nearly complete bone from the left rear corner of the skull preserves rows of bony knobs.
- The knobs have polygon-shaped bases and pointed tips, arranged in two divergent rows.
Borrowed from relatives
- The rounded skull roof is inferred from Prenocephale, and the missing snout from Stegoceras.
- A broad torso, strong hind legs and smaller arms follow Stegoceras; a long tail follows other pachycephalosaurs.
Still unknown
- The height and shape of its skull dome.
- The age of the animal represented by the skull bone.
- Its teeth, skin covering and color.
Discovery timeline
- 2006Named itSullivan
- 2022Close relativeMoore et al.
- 2023Family treeWoodruff, Schott & Evans
Key papers
The research behind what we know of Alaskacephale
Named it
Recognized a distinct bone-headed dinosaur from the arrangement and shape of knobs on a skull bone from Alaska.
A taxonomic review of the Pachycephalosauridae (Dinosauria: Ornithischia). Late Cretaceous Vertebrates from the Western Interior. New Mexico Museum of Natural History and Science Bulletin 35: 348-365
No link available
Close relative
Reconstructed limb muscles in Stegoceras, providing a comparison for the strong hind legs and broad pelvis inferred in Alaskacephale.
The appendicular myology of Stegoceras validum (Ornithischia: Pachycephalosauridae) and implications for the head-butting hypothesis. PLOS ONE 17: e0268144
Read the paper : The appendicular myology of Stegoceras validum (Ornithischia: Pachycephalosauridae) and implications for the head-butting hypothesis (opens in a new tab)Family tree
Compared skull knobs across bone-headed dinosaurs, including Alaskacephale, and examined their relationships.
Two new species of small‐bodied pachycephalosaurine (Dinosauria, Marginocephalia) from the uppermost Cretaceous of North America suggest hidden diversity in well‐sampled formations. Papers in Palaeontology 9
Read the paper : Two new species of small‐bodied pachycephalosaurine (Dinosauria, Marginocephalia) from the uppermost Cretaceous of North America suggest hidden diversity in well‐sampled formations (opens in a new tab)
Close relatives
Other members of Pachycephalosauridae
Sources: Wikidata