Stygimoloch in 3D - click the domed skull, the tail, or a leg for a fact (full controls on the Dinosaurs 3D hub).
Stygimoloch was a plant-eating dinosaur known for the spiky dome on top of its skull - turn on the human figure to see how a person compares to its body. Most specialists treat Stygimoloch as a subadult Pachycephalosaurus.
The measurements in the panel follow published estimates, with ranges shown where sources disagree.
Stygimoloch 3D Viewer
Drag to spin the Stygimoloch model below, zoom in close, and click the dome, a leg, or the tail to read a fact about that part (full controls on the Dinosaurs 3D hub).
Stygimoloch lived in the Late Cretaceous, about 67 to 66 million years ago, in western North America. Galton and Sues named it in 1983. Most specialists now treat it as a subadult growth stage of Pachycephalosaurus rather than a separate adult species. Length is about 3 m (NHM); other summaries cite about 3-4.2 m. Mass estimates vary widely (about 90-450 kg); this page uses about 200 kg as a mid-range figure.
| Measure | Figure |
|---|---|
| Length | about 3 m (NHM; other summaries about 3-4.2 m) |
| Standing height | about 1.5-1.7 m at the hips (proportionate estimate) |
| Weight | about 90-450 kg (panel about 200 kg mid-range) |
| When it lived | about 67-66 million years ago (Late Cretaceous) |
| Diet | Herbivore (limited omnivory debated) |
The viewer is 100% local via WebGL - no sign-in, no upload, and no data about your visit leaves the browser. For the larger adult dome-head already on this site, open the Pachycephalosaurus 3D Viewer.
Frequently Asked Questions
How big was Stygimoloch?
About 3 m long on the NHM summary, with other estimates about 3-4.2 m. Mass is poorly constrained (about 90-450 kg); this viewer cites about 200 kg as a mid-range figure and shows the range in the note. Turn on the human figure for scale.
Is Stygimoloch the same as Pachycephalosaurus?
Most specialists treat Stygimoloch as a subadult growth stage of Pachycephalosaurus rather than a separate adult genus. This page keeps the popular search name while stating that view. Compare with the Pachycephalosaurus 3D Viewer.
When and where did it live?
Late Cretaceous Maastrichtian of western North America, about 67-66 million years ago (Hell Creek and related units).
What does the name mean?
Stygimoloch means roughly "Styx demon," after the river Styx of Greek myth - a nod to the animal's horned, dome-headed skull.
Is the model scientifically accurate?
Proportions follow published figures with ranges, but skin color and soft tissue are artistic. This is not a fossil-accurate skeleton. The taxonomic status as a separate adult species is disputed.
Do I need to install anything to view it?
No. The model renders in your browser with WebGL - no app, no account, and nothing about your visit is sent to a server. When available, a free-licensed glTF model may swap in after first paint.