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Einiosaurus

Sampson, 1995 ie-nee-o-SAWR-us

From Blackfoot (Blackfeet Indian) 'eini' meaning 'bison' and Latinized Ancient Greek 'sauros' meaning 'lizard', meaning 'bison lizard'.

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

Einiosaurus is a genus of herbivorous centrosaurine ceratopsian dinosaur from the Upper Cretaceous (Campanian stage) of northwestern Montana. The name means 'bison lizard', in a combination of Blackfeet Indian eini and Latinized Ancient Greek sauros; the specific name (procurvicornis) means 'with a forward-curving horn' in Latin. Einiosaurus is medium-sized with an estimated body length at 4.5 meters (15 ft).

Diagnosis

  1. Long-based, laterally compressed nasal horn, strongly procurved in some adults
  2. Supraorbital horns, if present, low and rounded with convex medial surfaces
  3. Parietal with single pair of large, curved spikes projecting posteriorly from the posterior margin (Process 3)
  4. Nasal horncore extends posteriorly almost to the frontals in adults
  5. Laterally expanded supracranial cavity passing ventrally within the supraorbital horn, forming 'cornual' sinus analogous to bovids

Species

Einiosaurus procurvicornis Sampson, 1995

Type species

From Latin 'procurvicornis' meaning 'with a forward-curving horn', describing the characteristic strongly curved nasal horn of this ceratopsian.

Holotype
MOR 456-8-9-6-1 , Museum of the Rockies
Material
Incomplete skull with nasal horn, supraorbital regions, and partial parietal
Notes
Additional cranial and postcranial material from the type Canyon Bonebed, including a second adult skull, is cataloged under the same field number MOR 456 but is referred, not part of the holotype.
Horizon
upper Two Medicine Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
Canyon Bonebed, Montana, United States

References

  1. Sampson, S. D. (1995). Two new horned dinosaurs from the Upper Cretaceous Two Medicine Formation of Montana; with a phylogenetic analysis of the Centrosaurinae (Ornithischia: Ceratopsidae). Journal of Vertebrate Paleontology 15(4): 743-760. doi:10.1080/02724634.1995.10011259 sampson1995a