Open Paleo

Titanoceratops

Longrich, 2011 tie-TAN-o-SEH-ruh-tops Disputed

From Greek 'titanos' meaning 'titan' (giant) and 'ceratops' meaning 'horned face', in reference to its exceptionally large size among horned dinosaurs.

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

Titanoceratops is a controversial genus of chasmosaurine ceratopsian dinosaur that lived in the Late Cretaceous period (Campanian stage, about 75 million years ago) in what is now New Mexico. Titanoceratops was named for its large size, being one of the largest known horned dinosaurs and the type species was named T. ouranos, after Uranus (Ouranos), the father of the Greek titans. It was named in 2011 by Nicholas R. Longrich for a specimen previously referred to Pentaceratops. Longrich believed that unique features found in the skull reveal it to have been a close relative of Triceratops, classified within the subgroup Triceratopsini. However, other researchers have expressed skepticism, and believe Titanoceratops to simply be an unusually large, old specimen of Pentaceratops.

Under dispute

Titanoceratops is contested between a valid genus and an exceptionally large individual of Pentaceratops. Longrich (2011) erected it for OMNH 10165 and recovered it as the earliest triceratopsin, and Dalman and colleagues (2022) likewise recovered it within Triceratopsini. Lehman (1998) had interpreted the same specimen as an aberrant large Pentaceratops sternbergii, and Fowler and Freedman Fowler (2020) treat it as aff. Pentaceratops and exclude it from their matrix. Its resolution below subfamily level is therefore unsettled.

Diagnosis

  1. Extreme enlargement of the premaxillary fossa
  2. Thin squamosals with narrow parietal median bar
  3. Parietal fenestrae present
  4. Low and broad squamosal epoccipitals
  5. Vertically oriented narial strut with narrow base
  6. Large, horn-like epijugal oriented caudolaterally

Species

Titanoceratops ouranos Longrich, 2011 Disputed

Type species

Named for Ouranos (Uranus), the father of the Titans in Greek mythology, complementing the genus name which alludes to the mythological Titans.

Holotype
OMNH 10165 , Oklahoma Museum of Natural History
Material
Partial skeleton: partial skull and jaws, syncervical, cervical, dorsal and sacral vertebrae, caudal vertebrae, ribs, humeri, right radius, femora, tibiae, right fibula, ilia, ischia, and ossified tendons.
Horizon
Fruitland Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
5 miles south of Wood Ranch, New Mexico, United States

References

  1. Longrich, N. R. (2011). Titanoceratops ouranos, a giant horned dinosaur from the late Campanian of New Mexico. Cretaceous Research 32(3): 264-276. Elsevier BV. doi:10.1016/j.cretres.2010.12.007 longrich2011a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the hip height estimate, and the appearance features.

    jones2026a
  3. Fowler, D. W.; Freedman Fowler, E. A. (2020). Transitional evolutionary forms in chasmosaurine ceratopsid dinosaurs: evidence from the Campanian of New Mexico. PeerJ 8: e9251. PeerJ. doi:10.7717/peerj.9251

    Treated the specimen as aff. Pentaceratops and excluded it from their chasmosaurine phylogenetic matrix

    fowler2020a
  4. Dalman, S. G.; Jasinski, S. E.; Lucas, S. G. (2022). A new chasmosaurine ceratopsid from the Upper Cretaceous (Campanian) Farmington Member of the Kirtland Formation, New Mexico. New Mexico Museum of Natural History and Science Bulletin 90: 127-153.

    Phylogenetic analysis recovers Titanoceratops nested within Triceratopsini

    dalman2022a
  5. Lehman, T. M. (1998). A gigantic skull and skeleton of the horned dinosaur Pentaceratops sternbergi from New Mexico. Journal of Paleontology 72(5): 894-906. Cambridge University Press (CUP). doi:10.1017/S0022336000027220

    Described the giant skull later made the holotype of Titanoceratops as Pentaceratops.

    lehman1998a