Pachyrhinosaurus canadensis PAK-ee-RIE-noh-SOR-us
"Thick-nosed lizard"
You 1.8 m (5.9 ft) tall
Pachyrhinosaurus 7 m (23 ft) long
4 people holding hands
- Length
- 7 m (23 ft) — About 7 m long, ~4 tonnes — no nose horn, but a thick bony pad instead.
- Period
- Late Cretaceous (73–69 Mya)
- Place
- North America · Alberta, Canada · Alaska
- Food
- Herbivore — Tough plants — beak and tooth batteries similar to other ceratopsians.
Pachyrhinosaurus did not have a nose horn. Where other ceratopsians grew one, Pachyrhinosaurus grew a thick bony pad called a boss — possibly the base of a keratin horn that didn’t fossilize, or a pad for head-shoving contests with rivals. It lived as far north as Alaska, surviving long polar winters that most dinosaurs didn’t experience.
What we know
- Thick bony nose boss instead of a horn — unique among ceratopsians.
- Found as far north as Alaska, suggesting tolerance of polar conditions.
- Bonebeds preserve hundreds of individuals — large migrating herds are possible.
- Frill carried small horns and bumps, but no big spikes like Styracosaurus.
What we guess
- Whether the boss supported a keratin pad, a horn, or just a fleshy cushion.
- Whether Alaska populations migrated south for winter or stayed.
- Whether the boss was used in head-pushing contests like a modern musk ox.