Thagomizer: Difference between revisions

Revision as of 02:19, 1 May 2025

Revision as of 02:22, 1 May 2025

Line 1:

{{short description|Spike arrangement on stegosaur tails}}

{{Use mdy dates|date=May 2019}}

[[File:Thagomizer 01.jpg|thumb|Thagomizer on a mounted ''[[Stegosaurus]]'' tail]]

A '''thagomizer''' ({{IPAc-en|ˈ|θ|æ|ɡ|ə|m|aɪ|z|ər}}) is the distinctive arrangement of spikes on the tails of [[Stegosauria|stegosaurian]] dinosaurs. These spikes are believed to have been a defensive measure against predators.<ref>Holtz, T. R., (2000) "Classification and Evolution of the Dinosaur Groups" (pp. 140–168) in ''The Scientific American Book of Dinosaurs'', edited by [[Gregory S. Paul]], New York: St Martin's Press {{ISBN|0-312-26226-4}}.</ref><ref name="Carpenter Sanders">Carpenter, K., Sanders, F., McWhinney, L., and Wood, L. 2005. Evidence for predator-prey relationships: Example for ''Allosaurus'' and ''Stegosaurus''. Pp. 325-350 in Carpenter, K. (ed.) The Carnivorous Dinosaurs. Indiana University Press, Bloomington.</ref>

The arrangement of spikes originally had no distinct name. Cartoonist [[Gary Larson]] invented the name "thagomizer" in 1982 as a joke in his comic strip ''[[The Far Side]]'', and it was gradually adopted as an informal term sometimes used within scientific circles, research, and education.

Line 13:

== Paleobiology ==

[[File:Thagomizer.tif|thumb|left|The best evidence for the defensive use of the thagomizer is an ''Allosaurus'' tail [[vertebra]] with a hole perfectly matching a thagomizer spike.<ref name="Carpenter Sanders"/>spine]]

There has been debate about whether the thagomizer was used simply for display, as posited by Gilmore in 1914,<ref name="gilmore14">{{cite journal|author=Gilmore, C. W.|year=1914|title=Osteology of the armored Dinosauria in the United States National Museum, with special reference to the genus ''Stegosaurus''|url=https://archive.org/details/osteologyofarmor00gilm|journal=Series: Smithsonian Institution. United States National Museum. Bulletin 89|publisher=Government Printing Office, Washington|issue=89}}</ref> or used as a defensive weapon. [[Robert T. Bakker|Robert Bakker]] noted that it is likely that the stegosaur tail was much more flexible than those of other [[ornithischia]]n dinosaurs because it lacked ossified tendons, thus lending credence to the idea of the thagomizer being a weapon. He also observed that ''[[Stegosaurus]]'' could have maneuvered its rear easily by keeping its large hindlimbs stationary and pushing off with its very powerfully muscled but short forelimbs, allowing it to swivel deftly to deal with attack.<ref name="bakker86">{{cite book|author=Bakker, R. T.|url=https://archive.org/details/dinosaurheresies0000bakk|title=The Dinosaur Heresies|publisher=William Morrow|year=1986|___location=New York| isbn=9780688042875 |url-access=registration}}{{ISBN?}}{{page needed|date=June 2020}}</ref> In 2010, analysis of a digitized model of ''[[Kentrosaurus|Kentrosaurus aethiopicus]]'' showed that the tail could bring the thagomizer around to the sides of the dinosaur, possibly striking an attacker beside it.<ref name="NaishDK">{{cite web|author=Naish, Darren|year=2010|title=Heinrich's digital Kentrosaurus: the SJG stegosaur special, part II|url=http://scienceblogs.com/tetrapodzoology/2011/01/heinrichs_digital_kentrosaurus.php|url-status=dead|archive-url=https://web.archive.org/web/20110109004732/http://scienceblogs.com/tetrapodzoology/2011/01/heinrichs_digital_kentrosaurus.php|archive-date=January 9, 2011|access-date=January 19, 2011|work=Tetrapod Zoology}}</ref>