Open Paleo

Tylocephale

Maryańska & Osmólska, 1974 TIE-lo-SEF-a-lee

From Greek tylos meaning 'swelling' or 'knob' and kephale meaning 'head'; translates as 'swollen head,' referring to its domed skull

83.6–72.2 million years ago Campanian, Late Cretaceous
Late Cretaceous stages

Tylocephale is a genus of pachycephalosaurid dinosaur, a group of dome-headed, herbivorous ornithischians, that lived during the Maastrichtian stage 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 Baruungoyot 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.

Diagnosis

  1. Cranial roof highly thickened and elevated, highest dome point situated far posteriorly near skull margin
  2. Infratemporal fenestra very narrow, long, placed nearly vertically
  3. Orbit elongate and oblique, rising upward posteriorly
  4. Quadrate nearly vertical in orientation
  5. Occipital region narrow and very faintly depressed
  6. Posterior cheek region (jugal and quadratojugal) very strongly expanded laterally

Species

Tylocephale gilmorei Maryańska & Osmólska, 1974

Type species

Named for American paleontologist Charles Gilmore, who wrote the first detailed description of a pachycephalosaur.

Holotype
ZPAL MgD-I/105 , Institute of Paleobiology, Polish Academy of Sciences
Material
Damaged skull with maxillary teeth (lacking braincase, palate, and anterior snout); mandible with mandibular teeth (lacking anterior dentary)
Horizon
Baruungoyot Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
Khulsan, Central Cliffs, site 10, Ömnögovi, Mongolia

References

  1. Gradziński, R.; Jerzykiewicz, T. (1972). Additional geographical and geological data from the Polish-Mongolian Palaeontological Expeditions. Palaeontologia Polonica 27: 17-30.

    Maps the Khulsan finds, numbering a pachycephalosaurid skull 10, and calls the beds there the Lower Nemegt Beds.

    gradziński1972a
  2. Maryańska, T.; Osmólska, H. (1974). Pachycephalosauria, a new suborder of ornithischian dinosaurs. Palaeontologia Polonica 30: 45-102. Polish Academy of Sciences. maryańska1974a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the appearance features.

    jones2026a