| Tylocephale Temporal range: Late Campanian,
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| Diagram of the holotype skull | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | †Ornithischia |
| Clade: | †Neornithischia |
| Clade: | †Pachycephalosauria |
| Family: | †Pachycephalosauridae |
| Genus: | †Tylocephale Maryańska & Osmólska, 1974 |
| Species: | †T. gilmorei
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| Binomial name | |
| †Tylocephale gilmorei Maryańska & Osmólska, 1974
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Tylocephale (meaning "swollen head") is a genus of pachycephalosaurid dinosaur, a group of dome-headed, herbivorous ornithischians, that lived during the Late Campanian stage (75-73 million years ago) of the Late Cretaceous in what is now Mongolia. It is known from a partial skull and associated mandible that were unearthed in 1971 by a Polish-Mongolian Expedition to the Barun Goyot Formation of the Gobi Desert. The specimen was described in 1974 by Polish paleontologists Teresa Maryańska and Halszka Osmólska as a new genus and species.
It was average-sized for a pachycephalosaur, reaching 2 m (6.6 ft) in length and 40 kg (88 lb) in body mass. The skull is triangular in back view, the widest point being at the jugals with an apex at the top of the dome. Tylocephale's dome is the tallest known from a pachycephalosaur. This dome is also unusually thick and rugose on its exterior. Behind the dome, an array of spikes, nodes, and tubercules protrude posteriorly over the neck. The eyebrow ridge was ornamented with small, bony nodules and was thicker than in other genera. Tylocephale is closely related to other Asian pachycephalosaurs, like Homalocephale and Goyocephale, being part of the Old World branch of the group.
Being a pachycephalosaur it was herbivorous with small, ridged teeth adapted to break down fibrous plants. Its dentition also bears serrations, implying a potentially more heterogeneous diet of leaves, nuts, seeds, and insects. Fossils were found in the Khulsan locality, which preserves fossils of many other dinosaur groups like ceratopsians, ankylosaurs, oviraptorosaurs, dromaeosaurs, and a titanosaur. The Barun Goyot Formation was an alluvial plain, featuring large riverways in an arid to semi-arid climate.