thagomizer

File:Thagomizer.png cartoon is the source of the term thagomizer.]]

The term thagomizer was coined by Gary Larson in jest. In a 1982 The Far Side comic, a group of cavemen are taught by a caveman lecturer that the spikes on a stegosaur's tail were named "after the late Thag Simmons".{{Cite web|url=https://www.smithsonianmag.com/science-nature/watch-out-for-that-thagomizer-98891562/|title=Watch Out For That Thagomizer! |last=Black|first=Riley|date=March 30, 2011|website=Smithsonian.com|access-date=May 28, 2019}}

The term was picked up initially by Kenneth Carpenter, then a paleontologist at the Denver Museum of Nature and Science, who used the term when describing a fossil at the Society of Vertebrate Paleontology Annual Meeting in 1993.{{cite web|url=https://www.newscientist.com/channel/life/mg19125592.200-the-word-thagomizer.html|title= The word: Thagomizer|archive-url=https://web.archive.org/web/20070930013238/http://www.newscientist.com/channel/life/mg19125592.200-the-word-thagomizer.html |archive-date=September 30, 2007 |website=New Scientist|date=July 8, 2006|url-access=subscription }} Thagomizer has since been adopted as an informal anatomical term{{cite book |last=Holtz |first=Thomas, R. Jr. |author-link=Thomas R. Holtz Jr. |year=2007 |title=Dinosaurs: the Most Complete, Up-To-Date Encyclopedia for Dinosaur Lovers of All Ages |publisher=Random House |location=New York |isbn=978-0-375-82419-7 |page=[https://archive.org/details/dinosaursmostcom00holt/page/230 230] |url-access=registration |url=https://archive.org/details/dinosaursmostcom00holt/page/230 }} and is used by the Smithsonian Institution,{{cite web |url=http://www.nmnh.si.edu/paleo/dino/stegdcvr.htm |url-status=dead |archive-url=https://web.archive.org/web/20041214142258/http://www.nmnh.si.edu/paleo/dino/stegdcvr.htm |archive-date=December 14, 2004 |title=Stegosaurus Changes |publisher=Smithsonian National Museum of Natural History, Department of Paleobiology |access-date=March 3, 2007}} the Dinosaur National Monument, the book The Complete Dinosaur{{cite encyclopedia|first1=Peter M. |last1=Galton|author-link1=Peter Galton|editor1-last=Farlow|editor1-first=James Orville|editor2-last=Brett-Surman|editor2-first=M. K.|encyclopedia=The Complete Dinosaur|title=Stegosaurs|date=1999|publisher=Indiana University Press|pages=302|url=https://books.google.com/books?id=FOViD-lDPy0C&pg=302|access-date=December 11, 2016 |quote=In all stegosaurs, the terminal tail spines (thagomizer) presumably played a role in defense. |isbn=978-0253213136}} and the BBC documentary series Planet Dinosaur.{{Cite episode |title=Fight For Life |url=https://vimeo.com/131296159#t=9m14s |access-date=December 11, 2016 |series=Planet Dinosaur |network=BBC |station=BBC One |date=November 26, 2015 |season=1 |number=4 |time=9 minutes 14 seconds |quote=Stegosaurus: a heavily armored tank with a deadly weapon at the end of its tail, known as a thagomizer. |language=en}} The term has also appeared in some technical papers describing stegosaurs and related dinosaurs.{{Cite journal|last1=Mallison|first1=Heinrich|year=2011|title=Defense capabilities of Kentrosaurus aethiopicus Hennig, 1915|journal=Palaeontologia Electronica|volume=14|issue=2|pages=10A|url=https://www.uv.es/pe/2011_2/255/255.pdf}}{{Cite journal| doi = 10.1371/journal.pone.0224263| issn = 1932-6203| volume = 14| issue = 11| pages = –0224263| last1 = Costa| first1 = Francisco| last2 = Mateus| first2 = Octávio| title = Dacentrurine stegosaurs (Dinosauria): A new specimen of Miragaia longicollum from the Late Jurassic of Portugal resolves taxonomical validity and shows the occurrence of the clade in North America| journal = PLOS ONE| date = 2019-11-13| pmid = 31721771| pmc = 6853308| bibcode = 2019PLoSO..1424263C| doi-access = free}}{{Cite journal| doi = 10.1038/s41586-021-04147-1| last1 = Soto-Acuña| first1 = Sergio| last2 = Vargas| first2 = Alexander| last3 = Kaluza| first3 = Jonatan| last4 = Leppe| first4 = Marcelo| last5 = Botelho| first5 = Joao| last6 = Palma-Liberona| first6 = José| last7 = Gutstein| first7 = Carolina| last8 = Fernández| first8 = Roy| last9 = Ortiz| first9 = Hector| last10 = Milla| first10 = Verónica| last11 = Aravena| first11 = Bárbara| last12 = Manríquez| first12 = Leslie| last13 = Alarcón-Muñoz| first13 = Jhonatan| last14 = Pino| first14 = Juan| last15 = Trevisan| first15 = Christine| last16 = Mansilla| first16 = Héctor| last17 = Hinojosa| first17 = Luis| last18 = Muñoz-Walther| first18 = Vicente| last19 = Rubilar-Rogers| first19 = David| title = Bizarre tail weaponry in a transitional ankylosaur from subantarctic Chile| journal = Nature| date = 2021-12-01| volume = 600| issue = 7888| pages = 259–263| pmid = 34853468| bibcode = 2021Natur.600..259S| s2cid = 244799975}}{{Cite journal|doi=10.1007/s12542-022-00605-x |title=New thyreophoran dinosaur material from the Early Jurassic of northeastern Germany |date=2022 |last1=Schade |first1=Marco |last2=Ansorge |first2=Jörg |journal=PalZ |volume=96 |issue=2 |pages=303–311 |bibcode=2022PalZ...96..303S |doi-access=free }}{{cite journal |last1=Lategano |first1=Francesco |last2=Conti |first2=Simone |last3=Lozar |first3=Francesca |year=2024 |title=Miragaia tail biomechanics and defences. Evaluation of the tail mobility and resistance to loadings and collisions |journal=Rivista Italiana di Paleontologia e Stratigrafia |volume=130 |issue=2 |pages=475-486 |doi=10.54103/2039-4942/21688 |url=https://iris.unito.it/bitstream/2318/2034711/1/Lategano_et_al2024.pdf}}

File:Kentrosaurus aethiopicus 01.jpg]]

Some stegosaurs such as Kentrosaurus do not have a distinct "thagomizer" comprised of two pairs of spikes, as in these species there is not clear differentiation between the last two pairs on the tail and the other tail osteoderms, which are also spike-like, unlike the broad plate-like osteoderms on the back of Stegosaurus.{{Citation |last=Saitta |first=Evan T. |title=The function and Evolution of Stegosaur Osteoderms and Hypothesized Sexual Dimorphism in Hesperosaurus |date=2025-04-16 |url=http://biorxiv.org/lookup/doi/10.1101/2025.04.10.648273 |access-date=2025-05-28 |language=en |doi=10.1101/2025.04.10.648273 |last2=Bonhomme |first2=Vincent |last3=Lukens |first3=Mitchell |last4=Vidal |first4=Daniel |last5=Longrich |first5=Nicholas R. |last6=Richmond |first6=Dean R. |last7=Stockdale |first7=Maximilian T.|doi-access=free }}File:Thagomizer.tif with a hole matching a thagomizer spine]]

There has been debate about whether the thagomizer was used simply for display, as posited by Gilmore in 1914,{{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}} or used as a defensive weapon. Robert Bakker noted that it is likely that the stegosaur tail was much more flexible than those of other ornithischian 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.{{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}} In 2010, analysis of a digitized model of Kentrosaurus aethiopicus showed that the tail could bring the thagomizer around to the sides of the dinosaur, possibly striking an attacker beside it.{{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}}

In 2001, a study of thagomizers by McWhinney et al.{{cite book|last1=McWhinney |first1=L. A. |last2=Rothschild |first2=B. M. |last3=Carpenter |first3=K.|title=The Armored Dinosaurs|publisher=Indiana University Press|year=2001|isbn=978-0-253-33964-5|editor=Carpenter, Kenneth|pages=141–56|chapter=Posttraumatic Chronic Osteomyelitis in Stegosaurus dermal spikes}} showed a high incidence of trauma-related damage. This too supports the theory that the principal function of the thagomizer was defense in combat.

There is also evidence for Stegosaurus defending itself, in the form of an Allosaurus tail vertebra with a partially healed puncture wound that fits a Stegosaurus tail spike.{{cite book|last=Carpenter|first=Kenneth|url=https://archive.org/details/carnivorousdinos00carp|title=The Carnivorous Dinosaurs|author2=Sanders, Frank|author3=McWhinney, Lorrie A.|author4=Wood, Lowell|publisher=Indiana University Press|year=2005|isbn=978-0-253-34539-4|editor=Carpenter, Kenneth|location=Bloomington and Indianapolis|page=[https://archive.org/details/carnivorousdinos00carp/page/n330 325]|chapter=Evidence for predator-prey relationships: Examples for Allosaurus and Stegosaurus|url-access=limited|name-list-style=amp}} The species of stegosaur known as Stegosaurus stenops had four dermal spikes, each about {{cvt|60|-|90|cm|ft|0}} long. Discoveries of articulated stegosaur armor show that, at least in some species, these spikes protruded horizontally from the tail, not vertically as is often depicted.{{cite journal |last=Carpenter |first=Kenneth |year=1998 |journal=Modern Geology |title=Armor of Stegosaurus stenops, and the taphonomic history of a new specimen from Garden Park, Colorado |volume=23 |pages=127–44}} Initially, Othniel Charles Marsh described S. armatus as having eight spikes in its tail, unlike S. stenops. However, recent research re-examined this and concluded this species also had four.{{cite journal|last1=Marsh|first1=O. C|year=1877|title=A new order of extinct Reptilia (Stegosauria) from the Jurassic of the Rocky Mountains|url=https://zenodo.org/record/1450038|journal=American Journal of Science|volume=14|issue=84|pages=513–14|bibcode=1877AmJS...14..513M|doi=10.2475/ajs.s3-14.84.513|s2cid=130078453}}{{cite book|last1=Carpenter |first1=K. |last2=Galton |first2=P. M.|title=The Armored Dinosaurs|publisher=Indiana University Press|year=2001|isbn=978-0-253-33964-5|editor=Carpenter, Kenneth|pages=76–102|chapter=Othniel Charles Marsh and the Eight-Spiked Stegosaurus}}

File:Thagomizer-graph.svg]]

In a 2017 paper, the term thagomizer graph (and also the associated "thagomizer matroid") was introduced for the complete tripartite graph {{math|K_1,1,n}}.{{cite journal|last1=Gedeon|first1=Katie|last2=Proudfoot|first2=Nicholas|last3=Young|first3=Benjamin|date=2017|title=Kazhdan-Lusztig polynomials of matroids: a survey of results and conjectures|url=https://www.emis.de/journals/SLC/wpapers/FPSAC2017/80%20Gedeon%20Proudfoot%20Young.pdf|journal=Séminaire Lotharingien de Combinatoire|volume=78B|page=80|arxiv=1611.07474}}

In 2023, researchers at the University of California, San Francisco presented Thagomizer, a modality for the interrogation of RNA-protein binding events in CLIP-Seq (Cross-linking and immunoprecipitation) data.{{Cite journal |last1=Zhu |first1=Wandi S. |last2=Litterman |first2=Adam J. |last3=Sekhon |first3=Harshaan S. |last4=Kageyama |first4=Robin |last5=Arce |first5=Maya M. |last6=Taylor |first6=Kimberly E. |last7=Zhao |first7=Wenxue |last8=Criswell |first8=Lindsey A. |last9=Zaitlen |first9=Noah |last10=Erle |first10=David J. |last11=Ansel |first11=K. Mark |date=2023-12-07 |title=GCLiPP: global crosslinking and protein purification method for constructing high-resolution occupancy maps for RNA binding proteins |journal=Genome Biology |volume=24 |issue=1 |pages=281 |doi=10.1186/s13059-023-03125-2 |doi-access=free |issn=1474-760X |pmc=10701951 |pmid=38062486}}{{Cite web |title=Thagomizer |url=https://thagomizer.ucsf.edu/ |access-date=2024-01-12 |website=thagomizer.ucsf.edu}}

{{Portal|Dinosaurs}}

• Tail club
• Timeline of stegosaur research

{{reflist}}

{{Thefarside}}

Category:Dinosaur anatomy

Category:The Far Side

Category:Stegosauria

Category:1980s neologisms

Category:Words originating in fiction