Leptoceratops
| Leptoceratops Temporal range: Late Cretaceous (Maastrichtian),
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| Fossils at the Canadian Museum of Nature, Ottawa | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | †Ornithischia |
| Clade: | †Neornithischia |
| Clade: | †Ceratopsia |
| Family: | †Leptoceratopsidae |
| Genus: | †Leptoceratops Brown, 1914 |
| Species: | †L. gracilis
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| Binomial name | |
| †Leptoceratops gracilis Brown, 1914
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Leptoceratops (meaning 'Thin-horned face' and derived from Greek lepto-/λεπτο- meaning 'small', 'insignificant', 'slender', 'meagre' or 'lean', kerat-/κερατ- meaning 'horn' and -ops/ωψ meaning face),[1] is a genus of primitive ceratopsian dinosaurs from the late Cretaceous Period (late Maastrichtian age, 68.8-66 Ma ago[2]) of what is now Western North America. Their skulls have been found in Alberta, Canada and Wyoming.[3]
Description
Leptoceratops could probably stand and run on their hind legs: analysis of forelimb function indicates that even though they could not pronate their hands, they could walk on four legs.[4] Leptoceratops was around 2 metres (6.6 ft) long and could have weighed between 68 to 200 kilograms (150 to 441 lb).
Discovery and species
The first small ceratopsian named Leptoceratops was discovered in 1910 by Barnum Brown in the Red Deer Valley in Alberta, Canada. He described it four years later. The first specimen had a part of its skull missing, but there were later well-preserved finds by C. M. Sternberg in 1947, including one complete fossil. Later material was found in 1978 in the Bighorn Basin of northern Wyoming.
The type species is Leptoceratops gracilis. In 1942, material collected in Montana was named Leptoceratops cerorhynchos, but this was later renamed Montanoceratops.
Classification
Leptoceratops belonged to the Ceratopsia, a group of herbivorous dinosaurs with parrot-like beaks that thrived in North America and Asia during the Cretaceous Period. Although traditionally allied with the Protoceratopsidae, it is now placed in its own family, Leptoceratopsidae, along with dinosaurs such as Udanoceratops and Prenoceratops. The relationships of Leptoceratops to ceratopsids are not entirely clear. Although most studies suggest that they lie outside the protoceratopsids and ceratopsids, some studies suggest that they may be allied with Ceratopsidae. The absence of premaxillary teeth is one feature that supports this arrangement.
Paleobiology
Diet
Leptoceratops, like other ceratopsians, would have been a herbivore. The jaws were relatively short and deep, and the jaw muscles would have inserted over the large parietosquamosal frill, giving Leptoceratops a powerful bite.[5] The teeth are unusual in that the dentary teeth have dual wear facets, with a vertical wear facet where the maxillary teeth sheared past the crown, and a horizontal wear facet where the maxillary teeth crushed against the dentary teeth.[6] This shows that Leptoceratops chewed with a combination of shearing and crushing. Between the shearing/crushing action of the teeth and the powerful jaws, Leptoceratops was probably able to chew extremely tough plant matter.[7] Given its small size and quadrupedal stance, Leptoceratops would have been a low feeder. Flowering plants, also known as angiosperms, were the most diverse plants of the day, although ferns, cycads and conifers may still have been more common in terms of numbers.[8][9] A 2016 study revealed that Leptoceratops was able to chew its food much like several groups of mammals, which meant that it had a diet that consisted of tough, fibrous plant material.[10][11]
See also
References
- B. Brown. 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
- ^ Liddell, Henry George and Robert Scott (1980). A Greek-English Lexicon (Abridged ed.). United Kingdom: Oxford University Press. ISBN 0-19-910207-4.
- ^ Holtz, Thomas R. Jr. (2012). Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages (PDF).
- ^ Ostrom, John H. (May 1978). "Leptoceratops gracilis from the "Lance" Formation of Wyoming". Journal of Paleontology. 52 (3). SEPM Society for Sedimentary Geology: 697–704. JSTOR 1303974. Retrieved 17 November 2020.
- ^ Senter, P. (2007). "Analysis of forelimb function in basal ceratopsians". Journal of Zoology. 273 (3): 305–314. doi:10.1111/j.1469-7998.2007.00329.x.
- ^ Kyo, Tanoue (2008-01-01). Comparative anatomy and the masticatory system of basal Ceratopsia (Ornithischia, Dinosauria). ScholarlyCommons. OCLC 857236758.
- ^ Tanoue, Kyo; Grandstaff, Barbara S.; You, Hai-Lu; Dodson, Peter (September 2009). "Jaw Mechanics in Basal Ceratopsia (Ornithischia, Dinosauria)". The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology. 292 (9): 1352–1369. doi:10.1002/ar.20979. ISSN 1932-8486. PMID 19711460. S2CID 34736189.
- ^ Ostrom, John H. (September 1966). "Functional Morphology and Evolution of the Ceratopsian Dinosaurs". Evolution. 20 (3): 290–308. doi:10.2307/2406631. ISSN 0014-3820. JSTOR 2406631. PMID 28562975.
- ^ "Mammal-like mastication for the dinosaur Leptoceratops". phys.org. Retrieved 2021-06-27.
- ^ Lehman, Thomas M. (1987-01-01). "Late Maastrichtian paleoenvironments and dinosaur biogeography in the western interior of North America". Palaeogeography, Palaeoclimatology, Palaeoecology. 60: 189–217. Bibcode:1987PPP....60..189L. doi:10.1016/0031-0182(87)90032-0. ISSN 0031-0182.
- ^ Varriale, Frank (2016). "Dental microwear reveals mammal-like chewing in the neoceratopsian dinosaur Leptoceratops gracilis". PeerJ. 4: e2132. doi:10.7717/peerj.2132. PMC 4941762. PMID 27441111.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ Maiorino, Leonardo; Farke, Andrew A.; Kotsakis, Tassos; Raia, Pasquale; Piras, Paolo (2018-04-01). "Who is the most stressed? Morphological disparity and mechanical behavior of the feeding apparatus of ceratopsian dinosaurs (Ornithischia, Marginocephalia)". Cretaceous Research. 84: 483–500. doi:10.1016/j.cretres.2017.11.012. ISSN 0195-6671.
Sources
- Dodson, P. (1996). The Horned Dinosaurs. Princeton, New Jersey: Princeton University Press. pp. xiv-346. ISBN 9780691028828.
Media related to Leptoceratops at Wikimedia Commons
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