Leptoceratops
From Greek 'leptos' (small or slender), 'keras' (horn), and 'ops' (face); meaning 'small horn face'
Leptoceratops is a genus of ceratopsian dinosaur from the Late Cretaceous of North America. First found in Alberta in 1910, the type species Leptoceratops gracilis was named in 1914 by Barnum Brown for a partial skull and skeleton of two individuals found in the Scollard Formation of Alberta. Additional specimens found in the Scollard include one complete and two mostly complete skeletons together, uncovered in 1947 by Charles M. Sternberg. Specimens from Montana that were among the earliest referred to Leptoceratops have since been moved to their own genera Montanoceratops and Cerasinops, while new specimens of L. gracilis include bonebed remains from the Hell Creek Formation of Montana and a partial skeleton from the Lance Formation of Wyoming. Together with related taxa, Leptoceratops is the eponymous genus of the family Leptoceratopsidae. Leptoceratops is known from more than ten individuals, all from Maastrichtian deposits of Alberta, Montana and Wyoming, representing the entire skeleton.
Diagnosis
- Skull short and deep, without nasal horn; crest with high thin sagittal ridge and smooth posterior border
- Teeth single-rooted in both maxillary and dentary (bifid roots in all other known ceratopsians)
- Predentary relatively longer and comparatively heavier than in any described ceratopsian genus
- Caudal vertebrae with extremely high slender spines, proportionately higher than in any described Ceratopsian, and long chevrons
- Manus with digits I, II, and III terminating in narrow pointed hoofs; carpals fully ossified with large ulnare and radiale
- Femur shaft practically straight and round in cross-section; fourth trochanter comparatively larger than in any described Ceratopsian
Species
Leptoceratops gracilis Brown, 1914
Type species
From Latin 'gracilis' meaning 'slender', reflecting the slender build of the holotype specimen.
- Holotype
- AMNH 5205 , American Museum of Natural History
- Material
- Parts of skull and jaws (nasals, maxillaries, orbital border, back of crest, dentary, predentary, splenial), an articulated caudal series, a complete fore limb, and parts of the hind limbs
- Horizon
- Scollard Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
- Locality
- Three miles above Tolman Ferry, Alberta, Canada
Notable specimens
-
CMN 8889
Canadian Museum of Nature Found 1947 by Charles M. Sternberg most complete
The most complete known Leptoceratops, a skull, jaw, and most of a skeleton found in the Scollard Formation of Alberta. With the tail of CMN 8887 added, the reconstructed skeleton measures 1.81 meters. It was complete enough for Dale Russell to publish a fully reconstructed skeleton of the genus.
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UWGM-200
University of Wisconsin Geology Museum Found 1992 by Brig Konecke range extension
The rear part of a skull marking the first record of Leptoceratops from the Hell Creek Formation of Montana. Prepared in 1998, it preserves the first complete braincase yet described for the genus.
References
- Brown, B. (1914). Leptoceratops, a new genus of Ceratopsia from the Edmonton Cretaceous of Alberta. Bulletin of the American Museum of Natural History 33(36): 567-580. brown1914c
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Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.
Source of the hip height estimate, and the appearance features.
jones2026a - Sternberg, C. M. (1951). Complete skeleton of Leptoceratops gracilis Brown from the Upper Edmonton Member on Red Deer River, Alberta. National Museum of Canada Bulletin 123: 225-255. Natural Resources Canada/CMSS/Information Management. doi:10.4095/105059 sternberg1951a
- Ott, C. J. (2007). Cranial anatomy and biogeography of the first Leptoceratops gracilis (Dinosauria: Ornithischia) specimens from the Hell Creek Formation, Southeast Montana. Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs 213-234. Indiana University Press, Bloomington. ott2007a