Vtech 80-122400 Switch & Go Dinos - Horns the Triceratops, Ages 3-8

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Triceratops were long thought to have used their horns and frills in combat with large predators, such as Tyrannosaurus, the idea being discussed first by Charles H. Sternberg in 1917 and 70 years later by Robert Bakker. [55] [65] There is evidence that Tyrannosaurus did have aggressive head-on encounters with Triceratops, based on partially healed tyrannosaur tooth marks on a Triceratops brow horn and squamosal. The bitten horn is also broken, with new bone growth after the break. Which animal was the aggressor, however, is unknown. [66] Paleontologist Peter Dodson estimates that, in a battle against a bull Triceratops, the Triceratops had the upper hand and would successfully defend itself by inflicting fatal wounds to the Tyrannosaurus using its sharp horns. Tyrannosaurus is also known to have fed on Triceratops, as shown by a heavily tooth-scored Triceratops ilium and sacrum. [67] Examples of periosteal reactive bone in selected specimens of Triceratops Reid, R.E.H. (1997). "Histology of bones and teeth". In Currie, P. J.; Padian, K. (eds.). Encyclopedia of Dinosaurs. San Diego, CA.: Academic Press. pp.329–339. Scannella, John B.; Fowler, Denver W.; Goodwin, Mark B.; Horner, John R. (July 15, 2014). "Evolutionary trends in Triceratops from the Hell Creek Formation, Montana". Proceedings of the National Academy of Sciences. 111 (28): 10245–10250. Bibcode: 2014PNAS..11110245S. doi: 10.1073/pnas.1313334111. ISSN 0027-8424. PMC 4104892. PMID 24982159. Dodson, P. (1993). "Comparative craniology of the Ceratopsia" (PDF). American Journal of Science. 293: 200–234. Bibcode: 1993AmJS..293..200D. doi: 10.2475/ajs.293.A.200. Archived (PDF) from the original on August 19, 2018 . Retrieved January 21, 2007.

One skull was found with a hole in the jugal bone, apparently a puncture wound sustained while the animal was alive, as indicated by signs of healing. The hole has a diameter close to that of the distal end of a Triceratops horn. This and other apparent healed wounds in the skulls of ceratopsians has been cited as evidence of non-fatal intraspecific competition in these dinosaurs. [76] [77] Another specimen, referred to as "Big John", has a similar fenestra to the squamosal caused by what appears to be another Triceratops horn and the squamosal bone shows signs of significant healing, further vindicating the hypothesis that this ceratopsian used its horns for intra-specific combat. [78] a b Longrich, N. R.; Tokaryk, T.; Field, D. J. (2011). "Mass extinction of birds at the Cretaceous-Paleogene (K-Pg) boundary". Proceedings of the National Academy of Sciences. 108 (37): 15253–15257. Bibcode: 2011PNAS..10815253L. doi: 10.1073/pnas.1110395108. PMC 3174646. PMID 21914849. Early on, Lull postulated that the frills may have served as anchor points for the jaw muscles to aid chewing by allowing increased size and power for the muscles. [63] This has been put forward by other authors over the years, but later studies do not find evidence of large muscle attachments on the frill bones. [64]Tait, J.; Brown, B. (1928). "How the Ceratopsia carried and used their head". Transactions of the Royal Society of Canada. 22: 13–23. Holtz, Thomas R. Jr. (2012). Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages (PDF). Winter 2011 Appendix Like all chasmosaurines, Triceratops had a large skull relative to its body size, among the largest of all land animals. The largest-known skull, specimen MWC 7584 (formerly BYU 12183), is estimated to have been 2.5 meters (8.2ft) in length when complete [29] and could reach almost a third of the length of the entire animal. [30] Happ, J. (2008). "An analysis of predator-prey behavior in a head-to-head encounter between Tyrannosaurus rex and Triceratops". In Larson, P.; Carpenter, K. (eds.). Tyrannosaurus rex, the Tyrant King (Life of the Past). Bloomington: Indiana University Press. pp.355–368. ISBN 978-0-253-35087-9. Longrich, Nicholas R.; Field, Daniel J. (February 29, 2012). "Torosaurus Is Not Triceratops: Ontogeny in Chasmosaurine Ceratopsids as a Case Study in Dinosaur Taxonomy". PLOS ONE. 7 (2): e32623. Bibcode: 2012PLoSO...732623L. doi: 10.1371/journal.pone.0032623. ISSN 1932-6203. PMC 3290593. PMID 22393425.

a b Mathews, Joshua C.; Brusatte, Stephen L.; Williams, Scott A.; Henderson, Michael D. (2009). "The first Triceratops bonebed and its implications for gregarious behavior". Journal of Vertebrate Paleontology. 29 (1): 286–290. Bibcode: 2009JVPal..29..286M. doi: 10.1080/02724634.2009.10010382. S2CID 196608646. Ott, C.J.; Larson, P.L. (2010). "A New, Small Ceratopsian Dinosaur from the Latest Cretaceous Hell Creek Formation, Northwest South Dakota, United States: A Preliminary Description". In Ryan, M.J.; Chinnery-Allgeier, B.J.; Eberth, D.A. (eds.). New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium. Bloomington: Indiana University Press. p.656. a b Lamanna, M. C.; Sues, H. D.; Schachner, E. R.; Lyson, T. R. (2014). "A New Large-Bodied Oviraptorosaurian Theropod Dinosaur from the Latest Cretaceous of Western North America". PLOS ONE. 9 (3): e92022. Bibcode: 2014PLoSO...992022L. doi: 10.1371/journal.pone.0092022. PMC 3960162. PMID 24647078. Ostrom, J. H. (1964). "A functional analysis of jaw mechanics in the dinosaur Triceratops" (PDF). Postilla. 88: 1–35. Archived from the original (PDF) on June 26, 2010 . Retrieved November 20, 2010. The head of Triceratops was among the largest of all land animals, some making up one-third of the entire length of the dinosaur's body. The largest skull found has an estimated length of 8.2 feet (2.5 meters), according to Scannella's 2010 Journal of Vertebrate Paleontology study.We simply don’t know enough about their behavior because we can only study a small fraction that became fossilized. However, we do know that they likely battled amongst one another, as fossils with injuries from other Triceratops have been found. Reproduction of the Triceratops