# Pachycephalosaurus (Pachycephalosaurus wyomingensis) — DinoLand

> Field Journal — free dinosaur encyclopedia: 33 species with photos and video, catalog, ancient world maps (Triassic, Jurassic, Cretaceous, Gondwana), quiz, and paleontology glossary.

### id=16: Pachycephalosaurus (Pachycephalosaurus wyomingensis)

- URL: https://www.dinoland.ai/species.html?lang=en&id=16
- Diet: Herbivore
- Era: Cretaceous
- Period: 70–66 million years ago
- Length: 5 m
- Weight: ≈450 кг
- Height: 2 m
- Speed: ≈30 km/h
- Habitat: Open forests and ecotones toward inland plains
- Region: North America
- Discovered: 1931, Charles M. Gilmore

Fact: “Domed skull—contested head-butting versus flank-shoving displays.”

Description: Pachycephalosaurus is the extreme expression of pachycephalosaurine cranial thickening, with frontoparietal domes exceeding twenty centimeters of solid bone in large adults. While ramming combat is debated, comparative biomechanics favors low-intensity shoving matches and visual signaling. Juveniles exhibit flat skulls and spikes that remodel radically through ontogeny, formerly mistaken for distinct genera.

Features:
  - The dome is composed of uninterrupted cancellous and compact bone
  - Marginal osteoderms form irregular hornlets along the skull roof
  - Flat-headed juveniles document dramatic cranial growth trajectories

Related genera: Stegoceras, Dracorex, Homalocephale


## Citation

Field Journal — Dinosaur Encyclopedia — https://www.dinoland.ai

Web: https://www.dinoland.ai/species.html?lang=en&id=16
Index: https://www.dinoland.ai/llms-en.txt