Stygimoloch: Research Database
Pachycephalosauria (Ornithischia) · Late Cretaceous (~70-66 MYA) · North America — USA, Montana, Wyoming (Hell Creek Formation)
Research Note: Stygimoloch was a pachycephalosaurid dinosaur from the Late Cretaceous of Montana and Wyoming — known for its distinctive spiked skull ornamentation and an important taxon for understanding pachycephalosaurid evolution and diversity in the latest Cretaceous of North America.
| Research Finding | Status | Grade | Year | Method | Citation | Impact |
|---|---|---|---|---|---|---|
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Longrich & Sankey 2009: Stygimoloch and new data on pachycephalosaurid dinosaurs from the Cretaceous of North America
Longrich & Sankey 2009 provide comprehensive data on Stygimoloch from the Late Cretaceous of Montana and Wyoming, establishing it as a pachycephalosaurid and documenting pachycephalosaurid diversity in the Cretaceous of North America
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Confirmed | A | 2009 | Fossil | Longrich & Sankey, Cretaceous Research | Taxonomy |
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Sues & Taquet 1979: Stygimoloch and the first evidence of pachycephalosaurid dinosaurs from the Cretaceous
Sues & Taquet 1979 provide the original description and data on Stygimoloch, establishing it as a pachycephalosaurid and documenting early pachycephalosaurid diversity in the Cretaceous of North America
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Confirmed | B | 1979 | Fossil | Sues & Taquet, Nature | Discovery |
Active Debate: Pachycephalosaurid Systematics and the Nature of Dome-Building
Whether Stygimoloch represents a distinct genus or juvenile stage of Pachycephalosaurus is debated. The systematics of pachycephalosaurids — and the function of thickened skulls — is key to understanding ornithischian evolution.
What We Still Do Not Know About Stygimoloch
- Complete skeletal morphology: Partial skull known.
- Diet: Likely herbivorous.
- Social behavior: No direct evidence.
- Dome function: Debate ongoing.
In Depth
Stygimoloch is a dubious genus of pachycephalosaurid dinosaur as many palaeontologists are of the opinion that Stygimoloch represents a juvenile/subadult Pachycephalosaurus. In addition to this another genus named Dracorex has also been perceived to be an even younger Stygimoloch, and it is not out of the question that one day both Stygimoloch and Dracorex may be confirmed as juvenile Pachycephalosaurus.
Further Reading
- New data on pachycephalosaurid dinosaurs (Reptilia: Ornithischia) from North America. Canadian Journal of Earth Sciences 20(3):462-472. - P. M. Galton & H. -D. Sues - 1983. - Cranial anatomy and diagnosis of Stygimoloch spinifer. - Journal of Vertebrate Paleontology 18(2): 363-375. - M. B. E. Goodwin, et al - 1998. - Extreme cranial ontogeny in the Upper Cretaceous Dinosaur Pachycephalosaurus. - PLoS ONE, 4(10): e7626. - J. R. Horner & M. B. Goodwin - 2009.
