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{{Short description|Allosaurid theropod dinosaur genus from Late Jurassic period}}
{{Short description|Dubious saurischian dinosaur genus}}
{{Redirect|Saurophagus maximus|the bird|Saurophagus}}
{{Redirect|Saurophagus maximus|the bird|Saurophagus}}
{{Use mdy dates|date=January 2024}}
{{Use mdy dates|date=December 2024}}
{{Speciesbox
{{Speciesbox
| fossil_range = [[Late Jurassic]] ([[Tithonian]]), <br/>{{fossilrange|151|earliest=154|latest=142}}
| fossil_range = [[Late Jurassic]] <br/>{{fossilrange|Kimmeridgian|Kimmeridgian|[[Kimmeridgian]]}}
| image = Saurophaganax.jpg
| image = Saurophaganax maximus (holotype, OMNH 112).png
| image_caption = Holotype specimen, a dorsal neural arch
| image_upright = 1.15
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| display_parents = 2
| image_caption = Reconstructed skeleton at the [[Sam Noble Oklahoma Museum of Natural History]]
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| display_parents = 3
| genus = Saurophaganax
| genus = Saurophaganax
| species = maximus
| species = maximus
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}}
}}


'''''Saurophaganax''''' ("lord of lizard-eaters") is a [[nomen dubium|dubious]], [[Chimera (paleontology)|chimeric]] [[genus]] of large [[saurischian]] dinosaur, possibly a [[sauropod]], from the [[Late Jurassic]] ([[Kimmeridgian]]) [[Morrison Formation]] of [[Oklahoma]], United States. This taxon was historically considered to represent a species of ''[[Allosaurus]]'' or very large [[allosaurid]]. However, re-examinations of the attributed specimens suggested that it is a chimera of multiple dinosaur genera, since some specimens most likely belong to a [[diplodocid]] [[sauropod]], while the other referred specimens could be reassigned to a novel species of ''Allosaurus''.
'''''Saurophaganax''''' ("lord of lizard-eaters") is a [[genus]] of large [[allosaurid]] [[dinosaur]] from the [[Morrison Formation]] of [[Late Jurassic]] (latest [[Kimmeridgian]] age, about 151 million years ago) [[Oklahoma]], [[United States]].<ref name=turner1999>Turner, C.E. and Peterson, F., (1999). "Biostratigraphy of dinosaurs in the Upper Jurassic Morrison Formation of the Western Interior, U.S.A." Pp. 77–114 in Gillette, D.D. (ed.), ''Vertebrate Paleontology in Utah''. Utah Geological Survey Miscellaneous Publication 99-1.</ref> Some paleontologists consider it to be a junior synonym and species of ''[[Allosaurus]]'' (as ''A. maximus''). ''Saurophaganax'' represents a very large Morrison allosaurid characterized by horizontal laminae at the bases of the dorsal neural spines above the transverse processes, and "meat-chopper" [[Haemal arch|chevrons]].<ref name=DFG97>{{cite book |chapter=Saurophagus |last=Glut |first=Donald F. |title=Dinosaurs: The Encyclopedia |year=1997 |publisher=McFarland & Co |location=Jefferson, North Carolina |pages=793–794 |isbn=978-0-89950-917-4 }}</ref> It was the largest terrestrial carnivore of North America during the Late Jurassic, reaching {{convert|15.4|m|ft}} in length and {{convert|2.7|-|3.8|MT|ST}} in body mass.


==Discovery and naming==
==Discovery and naming==
[[File:Saurophaganax (2).jpg|thumb|left|A drawer of ''Saurophaganax'' vertebrae, Oklahoma Museum of Natural History]]
[[File:Saurophaganax (2).jpg|thumb|left|A drawer of vertebrae historically assigned to ''Saurophaganax'', Oklahoma Museum of Natural History]]
In 1931 and 1932, [[J. Willis Stovall|John Willis Stovall]] uncovered remains of a large theropod near [[Kenton, Oklahoma|Kenton]] in [[Cimarron County]], [[Oklahoma]] in layers of the late [[Kimmeridgian]]. In 1941, these were named ''Saurophagus maximus'' by Stovall in an article by journalist [[Grace Ernestine Ray]].<ref>Ray, G.E., 1941, "Big for his day", ''Natural History'' '''48''': 36–39</ref> The generic name is derived from Greek {{lang|grc|σαυρος}}, ''{{lang|grc-Latn|sauros}}'', "lizard", {{lang|grc|φάγειν}}, ''{{lang|grc-Latn|phagein}}'', "to eat", with the compound meaning of "lizard eater". The [[specific name (zoology)|specific epithet]] ''maximus'' means "the largest" in [[Latin]]. Because the naming article did not contain a description, the name remained a ''[[nomen nudum]]''. In 1987, [[Spencer George Lucas]] erroneously made OMNH 4666, a [[tibia]], the [[lectotype]], unaware that ''Saurophagus'' was a ''nomen nudum''.<ref>Lucas, S.G., Mateer, N.J., Hunt, A.P., and O'Neill, F.M., 1987, "Dinosaurs, the age of the Fruitland and Kirtland Formations, and the Cretaceous-Tertiary boundary in the San Juan Basin, New Mexico", p. 35-50. In: Fassett, J.E. and Rigby, J.K., Jr. (eds.), ''The Cretaceous-Tertiary boundary in the San Juan and Raton Basins, New Mexico and Colorado''. GSA Special Paper 209</ref>
In 1931 and 1932, [[J. Willis Stovall|John Willis Stovall]] uncovered remains of a large theropod near [[Kenton, Oklahoma|Kenton]] in [[Cimarron County]], [[Oklahoma]] in layers of the late [[Kimmeridgian]]. In 1941, these were named ''Saurophagus maximus'' by Stovall in an article by journalist [[Grace Ernestine Ray]].<ref>Ray, G.E., 1941, "Big for his day", ''Natural History'' '''48''': 36–39</ref> The generic name is derived from Greek {{lang|grc|σαυρος}}, ''{{lang|grc-Latn|sauros}}'', "lizard", {{lang|grc|φάγειν}}, ''{{lang|grc-Latn|phagein}}'', "to eat", with the compound meaning of "lizard eater". The [[specific name (zoology)|specific epithet]] ''maximus'' means "the largest" in [[Latin]]. Because the naming article did not contain a description, the name remained a ''[[nomen nudum]]''. In 1987, [[Spencer George Lucas]] erroneously made OMNH 4666, a [[tibia]], the [[lectotype]], unaware that ''Saurophagus'' was a ''nomen nudum''.<ref>Lucas, S.G., Mateer, N.J., Hunt, A.P., and O'Neill, F.M., 1987, "Dinosaurs, the age of the Fruitland and Kirtland Formations, and the Cretaceous-Tertiary boundary in the San Juan Basin, New Mexico", p. 35-50. In: Fassett, J.E. and Rigby, J.K., Jr. (eds.), ''The Cretaceous-Tertiary boundary in the San Juan and Raton Basins, New Mexico and Colorado''. GSA Special Paper 209</ref>


Later, it was discovered that the name ''Saurophagus'' was preoccupied: in 1831, it had already been given by [[William John Swainson|William Swainson]] to [[Great kiskadee|a tyrant-flycatcher]], an extant eater of taxonomically true lizards.<ref>W. Swainson and J. Richardson, 1831, ''Fauna boreali-americana, or, The zoology of the northern parts of British America: containing descriptions of the objects of natural history collected on the late northern land expeditions under command of Captain Sir John Franklin, R.N. Part 2, Birds'', London, J. Murray</ref> In 1995, [[Daniel Chure]] named a new genus: ''Saurophaganax'', adding Greek suffix -άναξ, ''{{lang|grc-Latn|anax}}'', meaning "ruler", to the earlier name. Chure also found OMNH 4666 undiagnostic in relation to ''Allosaurus'', so he chose OMNH 01123, a [[neural arch]], as the holotype for ''Saurophaganax''.<ref>Chure, D., 2000, ''A new species of ''Allosaurus'' from the Morrison Formation of Dinosaur National Monument (Utah-Colorado) and a revision of the theropod family Allosauridae''. Ph.D. dissertation, Columbia University, pp. 1–964</ref> — and ''Saurophaganax'' is not a renaming of "Saurophagus".<ref name=DJC95>{{cite book |last=Chure |first=Daniel J. |editor=A. Sun |editor2=Y. Wang |title=Sixth Symposium on Mesozoic Terrestrial Ecosystems and Biota, Short Papers |year=1995 |publisher=China Ocean Press |location=Beijing |pages=103–106 |chapter=A reassessment of the gigantic theropod ''Saurophagus maximus'' from the Morrison Formation (Upper Jurassic) of Oklahoma, USA }}</ref> Much of the material informally named "Saurophagus maximus", namely those diagnostic elements that could be distinguished from ''Allosaurus'', were referred to ''Saurophaganax maximus'' by Chure. They contain disarticulated bones of at least four individuals.<ref name=DJC95/>
Later, it was discovered that the name ''Saurophagus'' was preoccupied: in 1831, it had already been given by [[William John Swainson|William Swainson]] to [[Great kiskadee|a tyrant-flycatcher]], an extant eater of taxonomically true lizards.<ref>W. Swainson and J. Richardson, 1831, ''Fauna boreali-americana, or, The zoology of the northern parts of British America: containing descriptions of the objects of natural history collected on the late northern land expeditions under command of Captain Sir John Franklin, R.N. Part 2, Birds'', London, J. Murray</ref> In 1995, [[Daniel Chure]] named a new genus ''Saurophaganax'', adding Greek suffix -άναξ, ''{{lang|grc-Latn|anax}}'' which means "ruler", replacing the earlier informal name "Saurophagus"; he also found OMNH 4666 undiagnostic in relation to ''Allosaurus'', so he chose OMNH 1123, a [[neural arch]], as the holotype for ''Saurophaganax''.<ref name=DJC95>{{cite book |last=Chure |first=Daniel J. |editor=A. Sun |editor2=Y. Wang |title=Sixth Symposium on Mesozoic Terrestrial Ecosystems and Biota, Short Papers |year=1995 |publisher=China Ocean Press |location=Beijing |pages=103–106 |chapter=A reassessment of the gigantic theropod ''Saurophagus maximus'' from the Morrison Formation (Upper Jurassic) of Oklahoma, USA }}</ref><ref>Chure, D., 2000, ''A new species of ''Allosaurus'' from the Morrison Formation of Dinosaur National Monument (Utah-Colorado) and a revision of the theropod family Allosauridae''. Ph.D. dissertation, Columbia University, pp. 1–964</ref> Much of the material informally named "Saurophagus maximus", namely those diagnostic elements that could be distinguished from ''Allosaurus'', were referred to ''Saurophaganax maximus'' by Chure; they contain disarticulated bones of at least four individuals.<ref name=DJC95/>


In 2024, Danison and colleagues revised the referral of various specimens assigned to ''Saurophaganax maximus'' including the fragmentary holotype neural arch (OMNH 1123) based on their comparative analysis. They suggested that the holotype could not confidently be regarded as a theropod or sauropod, although the complex accessory laminae are more comparable to those of sauropods, especially some juvenile specimens of ''Apatosaurus''. Some referred specimens more likely belong to diplodocids than the large Kenton 1 Quarry allosaurid. Since the holotype neural arch is so fragmentary, the researchers couldn't confidently refer it to a theropod or sauropod, so they considered ''Saurophaganax maximus'' to be a ''[[nomen dubium]]''.<ref name=chimera/>
''Saurophaganax'' is the official [[state fossil]] of [[Oklahoma]],<ref>{{cite web |url=http://www.okinsider.com/kidsonly04.oki |title=OK State Symbols |work=OkInsider.com |publisher=Oklahoma Publishing Today |access-date=December 27, 2007 |year=2006 |archive-url = https://web.archive.org/web/20070807232519/http://www.okinsider.com/kidsonly04.oki <!-- Bot retrieved archive --> |archive-date = August 7, 2007}}</ref> and a large skeleton of ''Saurophaganax'' can be seen in the Jurassic hall in the [[Sam Noble Oklahoma Museum of Natural History]]. Although the best known ''Saurophaganax'' material was found in the panhandle of Oklahoma, possible ''Saurophaganax'' material, NMMNH P-26083, a partial skeleton including a femur, several tail vertebrae, and a hip bone, has been found in northern [[New Mexico]].<ref name=":0">{{Cite book|last=Foster|first=John|title=Jurassic West: the Dinosaurs of the Morrison Formation and Their World.|publisher=Bloomington, Indiana:Indiana University Press.|year=2007|pages=117}}</ref>


=== Previously assigned allosaurid specimens ===
===Relationship with ''Allosaurus'' ===
[[File:Clash of Titans Saurophaganax and Apatosaurus.jpg|thumb|left|upright=1.0|Mounted skeletons showing ''Saurophaganax'' as an ''[[Allosaurus]]''-like taxon attacking ''[[Apatosaurus]]'' sp., in [[Oklahoma Museum of Natural History]]. The latter dinosaur may be closer to the actual identity of ''Saurophaganax'']]
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The identification of the allosaurid elements referred to ''Saurophaganax'' was a matter of dispute. It has been described as its own genus,<ref name=DJC95/> or as a species of ''Allosaurus'': ''Allosaurus maximus''.<ref name=DKS98>{{cite journal |doi=10.1080/02724634.1998.10011039 |last=Smith |first=David K. |year=1998 |title=A morphometric analysis of ''Allosaurus'' |journal=Journal of Vertebrate Paleontology |volume=18 |issue=1 |pages=126–142|bibcode=1998JVPal..18..126S }}</ref> A review of basal tetanurans in 2004 and Carrano et al.'s comprehensive 2012 analysis of Tetanurae accepted ''Saurophaganax'' as a distinct genus.<ref name=HMC04>{{cite book|last=Holtz |first=Thomas R. Jr. |author-link=Thomas R. Holtz Jr. |author2=Molnar, Ralph E. |author3= Currie, Philip J. |year=2004 |editor=Weishampel, David B. |editor2=Dodson, Peter |editor3= Osmólska, Halszka |title=The Dinosauria |edition=2nd |publisher=University of California Press |location=Berkeley |isbn=978-0-520-24209-8 |pages=71–110 }}</ref><ref>{{Cite journal |last1=Carrano |first1=Matthew T. |last2=Benson |first2=Roger B. J. |last3=Sampson |first3=Scott D. |date=June 1, 2012 |title=The phylogeny of Tetanurae (Dinosauria: Theropoda) |url=https://doi.org/10.1080/14772019.2011.630927 |journal=Journal of Systematic Palaeontology |volume=10 |issue=2 |pages=211–300 |doi=10.1080/14772019.2011.630927 |bibcode=2012JSPal..10..211C |s2cid=85354215 |issn=1477-2019}}</ref> Possible ''Saurophaganax'' material from New Mexico may clear up the status of the genus.<ref name=":0">{{Cite book|last=Foster|first=John|title=Jurassic West: the Dinosaurs of the Morrison Formation and Their World.|publisher=Bloomington, Indiana:Indiana University Press.|year=2007|pages=117}}</ref> In 2019, Rauhut and colleagues noted that the definitive taxonomic placement of ''Saurophaganax'' within [[Allosauroidea]] is unstable, being recovered as a sister taxon of [[Metriacanthosauridae]] or Allosauria, or even as a basalmost carcharodontosaurian.<ref name="Rauhut2019">{{Cite journal|last1=Rauhut|first1=Oliver W. M.|last2=Pol|first2=Diego|date=December 11, 2019|title=Probable basal allosauroid from the early Middle Jurassic Cañadón Asfalto Formation of Argentina highlights phylogenetic uncertainty in tetanuran theropod dinosaurs|journal=Scientific Reports|language=en|volume=9|issue=1|pages=18826|doi=10.1038/s41598-019-53672-7|pmid=31827108|pmc=6906444|issn=2045-2322}} [https://www.nature.com/articles/s41598-019-53672-7#MOESM1 Supplementary information]</ref> Re-evaluation of the assigned specimens in a 2024 reassessment suggested that the referred allosaurid specimens belong to a novel species of ''[[Allosaurus]]'', named as ''Allosaurus anax''.<ref name=chimera>{{Cite journal |last1=Danison |first1=Andrew |last2=Wedel |first2=Mathew |last3=Barta |first3=Daniel |last4=Woodward |first4=Holly |last5=Flora |first5=Holley |last6=Lee |first6=Andrew |last7=Snively |first7=Eric |date=December 21, 2024 |title=Chimerism in specimens referred to ''Saurophaganax maximus'' reveals a new species of ''Allosaurus'' (Dinosauria, Theropoda) |url=https://journals.library.ualberta.ca/vamp/index.php/VAMP/article/view/29404 |journal=Vertebrate Anatomy Morphology Palaeontology |language=en |volume=12 |doi=10.18435/vamp29404 |issn=2292-1389|doi-access=free }}</ref>


==Paleoenvironment==
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The identification of ''Saurophaganax'' is a matter of dispute. It has been described as its own genus,<ref name=DJC95/> or as a species of ''Allosaurus'': ''Allosaurus maximus''.<ref name=DKS98>{{cite journal |doi=10.1080/02724634.1998.10011039 |last=Smith |first=David K. |year=1998 |title=A morphometric analysis of ''Allosaurus'' |journal=Journal of Vertebrate Paleontology |volume=18 |issue=1 |pages=126–142|bibcode=1998JVPal..18..126S }}</ref> A review of basal tetanurans in 2004 and Carrano et al.'s comprehensive 2012 analysis of Tetanurae accepted ''Saurophaganax'' as a distinct genus.<ref name=HMC04>{{cite book|last=Holtz |first=Thomas R. Jr. |author-link=Thomas R. Holtz Jr. |author2=Molnar, Ralph E. |author3= Currie, Philip J. |year=2004 |editor=Weishampel, David B. |editor2=Dodson, Peter |editor3= Osmólska, Halszka |title=The Dinosauria |edition=2nd |publisher=University of California Press |location=Berkeley |isbn=978-0-520-24209-8 |pages=71–110 }}</ref><ref>{{Cite journal |last1=Carrano |first1=Matthew T. |last2=Benson |first2=Roger B. J. |last3=Sampson |first3=Scott D. |date=June 1, 2012 |title=The phylogeny of Tetanurae (Dinosauria: Theropoda) |url=https://doi.org/10.1080/14772019.2011.630927 |journal=Journal of Systematic Palaeontology |volume=10 |issue=2 |pages=211–300 |doi=10.1080/14772019.2011.630927 |bibcode=2012JSPal..10..211C |s2cid=85354215 |issn=1477-2019}}</ref> Possible ''Saurophaganax'' material from New Mexico may clear up the status of the genus.<ref name=":0" />

==Description==
[[File:Saurophaganax Scale.svg|thumb|left|Size comparison]]
''Saurophaganax'' was the largest carnivore found in the [[Morrison Formation]], bigger than both its contemporaries ''[[Torvosaurus tanneri]]'' and ''[[Allosaurus fragilis]]'', reaching {{convert|10.5|m|ft}} in length and {{convert|2.7|-|3.8|MT|ST}} in body mass.<ref>{{cite journal|last1=Farlow|first1=J. O.|last2=Coroian|first2=D.|last3=Currie|first3=P.J.|last4=Foster|first4=J.R.|last5=Mallon|first5=J.C.|last6=Therrien|first6=F.|year=2022|title="Dragons" on the landscape: Modeling the abundance of large carnivorous dinosaurs of the Upper Jurassic Morrison Formation (USA) and the Upper Cretaceous Dinosaur Park Formation (Canada)|journal=The Anatomical Record|volume=306 |issue=7 |pages=1669–1696 |doi=10.1002/ar.25024|doi-access=free|pmid=35815600}}</ref><ref>{{cite book | url=https://archive.org/details/princetonfieldgu0000paul/page/96 |title=The Princeton Field Guide to Dinosaurs | publisher=Princeton University Press | last=Paul | first=G. S. | author-link=Gregory S. Paul | year=2010 | pages=[https://archive.org/details/princetonfieldgu0000paul/page/96 96] | isbn=978-0-691-13720-9 }}</ref><ref>{{Cite journal |last1=Persons |first1=S. W. |last2=Currie |first2=P. J. |last3=Erickson |first3=G. M. |title=An Older and Exceptionally Large Adult Specimen of ''Tyrannosaurus rex'' |journal=The Anatomical Record |volume=303 |issue=4 |pages=656–672 |doi=10.1002/ar.24118 |pmid=30897281 |issn=1932-8486|year=2020 |doi-access=free }}</ref><ref>{{Cite journal|last1=Campione|first1=Nicolás E.|last2=Evans|first2=David C.|date=2020|title=The accuracy and precision of body mass estimation in non-avian dinosaurs|journal=Biological Reviews|language=en|volume=95|issue=6|pages=1759–1797|doi=10.1111/brv.12638|pmid=32869488|s2cid=221404013|issn=1469-185X|doi-access=free}}</ref>

==Paleoecology==
[[File:Saurophaganax restoration 2019 by Mario Lanzas.jpg|thumb|[[Life reconstruction]]]]
The Morrison Formation is a sequence of shallow marine and alluvial sediments which, according to [[radiometric dating]], ranges between 156.3 million years old ([[Mega-annum|Ma]]) at its base,<ref name=TCR06>{{cite journal |last=Trujillo |first=K.C. |author2=Chamberlain, K.R. |author3= Strickland, A. |year=2006 |title=Oxfordian U/Pb ages from SHRIMP analysis for the Upper Jurassic Morrison Formation of southeastern Wyoming with implications for biostratigraphic correlations |journal=Geological Society of America Abstracts with Programs |volume=38 |issue=6 |page=7}}</ref> to 146.8 million years old at the top,<ref name=SAB98>{{cite book |last=Bilbey |first=S.A. |year=1998 |chapter=Cleveland-Lloyd Dinosaur Quarry – age, stratigraphy and depositional environments |pages= 87–120 |title=The Morrison Formation: An Interdisciplinary Study |editor1=Carpenter, K. |editor2=Chure, D. |editor3=Kirkland, J.I. |series=Modern Geology '''22''' |publisher=Taylor and Francis Group |issn=0026-7775}}</ref> which places it in the late [[Oxfordian stage|Oxfordian]], [[Kimmeridgian]], and early [[Tithonian]] [[faunal stages|stages]] of the Late Jurassic period. This formation is interpreted as a [[semiarid]] environment with distinct [[wet season|wet]] and [[dry season]]s. The Morrison Basin where dinosaurs lived, stretched from New Mexico to Alberta and Saskatchewan, and was formed when the precursors to the [[Front Range]] of the Rocky Mountains started pushing up to the west. The deposits from their east-facing [[drainage basin]]s were carried by streams and [[river]]s and deposited in [[swamp]]y lowlands, lakes, river channels and [[floodplain]]s.<ref name=DAR89>{{cite book |last=Russell |first=Dale A. |author-link=Dale Russell |title=An Odyssey in Time: Dinosaurs of North America |year=1989 |publisher=NorthWord Press |location=Minocqua, Wisconsin |isbn=978-1-55971-038-1 |pages=64–70 }}</ref> This formation is similar in age to the [[Solnhofen limestone|Solnhofen Limestone]] Formation in [[Germany]] and the [[Tendaguru|Tendaguru Formation]] in [[Tanzania]]. The fossils known of ''Saurophaganax'' (both the possible material from New Mexico and the Oklahoma material) are known from the Brushy Basin Member, which is the latest part of the Morrison Formation, suggesting that this genus was either always uncommon or that it first appeared rather late in the Jurassic. Because of the rarity of discovered remains, not much about its behavior is known.<ref>{{cite book|last1=Foster|first1=J.|year=2020|title=Jurassic West, Second Edition: The Dinosaurs of the Morrison Formation and Their World (Life of the Past)|publisher=Indiana University Press|isbn=9780253051578}}</ref>
The Morrison Formation is a sequence of shallow marine and alluvial sediments which, according to [[radiometric dating]], ranges between 156.3 million years old ([[Mega-annum|Ma]]) at its base,<ref name=TCR06>{{cite journal |last=Trujillo |first=K.C. |author2=Chamberlain, K.R. |author3= Strickland, A. |year=2006 |title=Oxfordian U/Pb ages from SHRIMP analysis for the Upper Jurassic Morrison Formation of southeastern Wyoming with implications for biostratigraphic correlations |journal=Geological Society of America Abstracts with Programs |volume=38 |issue=6 |page=7}}</ref> to 146.8 million years old at the top,<ref name=SAB98>{{cite book |last=Bilbey |first=S.A. |year=1998 |chapter=Cleveland-Lloyd Dinosaur Quarry – age, stratigraphy and depositional environments |pages= 87–120 |title=The Morrison Formation: An Interdisciplinary Study |editor1=Carpenter, K. |editor2=Chure, D. |editor3=Kirkland, J.I. |series=Modern Geology '''22''' |publisher=Taylor and Francis Group |issn=0026-7775}}</ref> which places it in the late [[Oxfordian stage|Oxfordian]], [[Kimmeridgian]], and early [[Tithonian]] [[faunal stages|stages]] of the Late Jurassic period. This formation is interpreted as a [[semiarid]] environment with distinct [[wet season|wet]] and [[dry season]]s. The Morrison Basin where dinosaurs lived, stretched from New Mexico to Alberta and Saskatchewan, and was formed when the precursors to the [[Front Range]] of the Rocky Mountains started pushing up to the west. The deposits from their east-facing [[drainage basin]]s were carried by streams and [[river]]s and deposited in [[swamp]]y lowlands, lakes, river channels and [[floodplain]]s.<ref name=DAR89>{{cite book |last=Russell |first=Dale A. |author-link=Dale Russell |title=An Odyssey in Time: Dinosaurs of North America |year=1989 |publisher=NorthWord Press |location=Minocqua, Wisconsin |isbn=978-1-55971-038-1 |pages=64–70 }}</ref> This formation is similar in age to the [[Solnhofen limestone|Solnhofen Limestone]] Formation in [[Germany]] and the [[Tendaguru|Tendaguru Formation]] in [[Tanzania]]. The fossils known of ''Saurophaganax'' (both the possible material from New Mexico and the Oklahoma material) are known from the Brushy Basin Member, which is the latest part of the Morrison Formation, suggesting that this genus was either always uncommon or that it first appeared rather late in the Jurassic. Because of the rarity of discovered remains, not much about its behavior is known.<ref>{{cite book|last1=Foster|first1=J.|year=2020|title=Jurassic West, Second Edition: The Dinosaurs of the Morrison Formation and Their World (Life of the Past)|publisher=Indiana University Press|isbn=9780253051578}}</ref>


⚫
The Morrison Formation records an environment and time dominated by gigantic sauropod dinosaurs such as ''[[Barosaurus]]'', ''[[Apatosaurus]]'', ''[[Brontosaurus]]'', ''[[Camarasaurus]]'', ''[[Diplodocus]]'', and ''[[Brachiosaurus]]''. Dinosaurs that lived alongside ''Saurophaganax'' included the herbivorous [[ornithischians]] ''[[Camptosaurus]]'', ''[[Dryosaurus]]'', ''[[Stegosaurus]]'', and ''[[Nanosaurus]]''. Predators in this paleoenvironment included the [[theropods]] ''[[Torvosaurus]]'', ''[[Ceratosaurus]]'', ''[[Marshosaurus]]'', ''[[Stokesosaurus]]'', ''[[Ornitholestes]]'', and<ref>Foster, J. (2007). "Appendix." Jurassic West: The Dinosaurs of the Morrison Formation and Their World. Indiana University Press. pp. 327–329.</ref> ''[[Allosaurus]]'', which accounted for 70 to 75% of theropod specimens and was at the top [[trophic level]] of the Morrison [[food chain|food web]].<ref name=JRF03a>{{cite book |last=Foster |first=John R. |title=Paleoecological Analysis of the Vertebrate Fauna of the Morrison Formation (Upper Jurassic), Rocky Mountain Region, U.S.A. |year=2003 |series=New Mexico Museum of Natural History and Science Bulletin, '''23''' |publisher=New Mexico Museum of Natural History and Science |location=Albuquerque, New Mexico |page=29}}</ref> Other vertebrates that shared this paleoenvironment included [[actinopterygii|ray-finned fishes]], [[frog]]s such as ''[[Eobatrachus]]'', [[salamander]]s, [[turtle]]s, [[sphenodontia|sphenodonts]], [[lizard]]s, terrestrial and aquatic [[crocodylomorpha|crocodylomorphs]] like ''[[Goniopholis]]'', and several species of [[pterosaur]] like ''[[Kepodactylus]]''. Early mammals were present in this region, such as ''[[Fruitafossor]]'', [[docodonts]], [[multituberculates]], symmetrodonts, and [[triconodonts]]. The flora of the period has been revealed by fossils of [[chlorophyta|green algae]], [[fungi]], [[moss]]es, [[equisetum|horsetails]], [[cycad]]s, [[ginkgo]]es, and several families of [[conifer]]s. Vegetation varied from [[river]]-lining forests of [[tree fern]]s, and [[fern]]s ([[gallery forest]]s), to fern [[savanna]]s with occasional trees such as the ''[[Araucaria]]''-like conifer ''[[Brachyphyllum]]''.<ref name=KC06>{{cite book |last=Carpenter |first=Kenneth |author-link=Kenneth Carpenter |year=2006 |chapter=Biggest of the big: a critical re-evaluation of the mega-sauropod ''Amphicoelias fragillimus'' |editor1=Foster, John R. |editor2=Lucas, Spencer G. |title=Paleontology and Geology of the Upper Jurassic Morrison Formation |series=New Mexico Museum of Natural History and Science Bulletin, '''36''' |publisher=New Mexico Museum of Natural History and Science |location=Albuquerque, New Mexico |pages=131–138 }}</ref>
[[File:Saurophaganax VS Diplodocus.jpg|thumb|left|Mounted skeleton posed attacking a ''[[Diplodocus]]'', [[New Mexico Museum of Natural History and Science|New Mexico Museum of Natural History & Science]].]]
⚫
The Morrison Formation records an environment and time dominated by gigantic sauropod dinosaurs such as ''[[Barosaurus]]'', ''[[Apatosaurus]]'', ''[[Brontosaurus]]'', ''[[Camarasaurus]]'', ''[[Diplodocus]]'', and ''[[Brachiosaurus]]''. Dinosaurs that lived alongside ''Saurophaganax'', and may have served as prey, included the herbivorous [[ornithischians]] ''[[Camptosaurus]]'', ''[[Dryosaurus]]'', ''[[Stegosaurus]]'', and ''[[Nanosaurus]]''. Predators in this paleoenvironment included the [[theropods]] ''[[Torvosaurus]]'', ''[[Ceratosaurus]]'', ''[[Marshosaurus]]'', ''[[Stokesosaurus]]'', ''[[Ornitholestes]]'', and<ref>Foster, J. (2007). "Appendix." Jurassic West: The Dinosaurs of the Morrison Formation and Their World. Indiana University Press. pp. 327–329.</ref> ''[[Allosaurus]]'', which accounted for 70 to 75% of theropod specimens and was at the top [[trophic level]] of the Morrison [[food chain|food web]].<ref name=JRF03a>{{cite book |last=Foster |first=John R. |title=Paleoecological Analysis of the Vertebrate Fauna of the Morrison Formation (Upper Jurassic), Rocky Mountain Region, U.S.A. |year=2003 |series=New Mexico Museum of Natural History and Science Bulletin, '''23''' |publisher=New Mexico Museum of Natural History and Science |location=Albuquerque, New Mexico |page=29}}</ref> Other vertebrates that shared this paleoenvironment included [[actinopterygii|ray-finned fishes]], [[frog]]s such as ''[[Eobatrachus]]'', [[salamander]]s, [[turtle]]s, [[sphenodontia|sphenodonts]], [[lizard]]s, terrestrial and aquatic [[crocodylomorpha|crocodylomorphs]] like ''[[Goniopholis]]'', and several species of [[pterosaur]] like ''[[Kepodactylus]]''. Early mammals were present in this region, such as ''[[Fruitafossor]]'', [[docodonts]], [[multituberculates]], symmetrodonts, and [[triconodonts]]. The flora of the period has been revealed by fossils of [[chlorophyta|green algae]], [[fungi]], [[moss]]es, [[equisetum|horsetails]], [[cycad]]s, [[ginkgo]]es, and several families of [[conifer]]s. Vegetation varied from [[river]]-lining forests of [[tree fern]]s, and [[fern]]s ([[gallery forest]]s), to fern [[savanna]]s with occasional trees such as the ''[[Araucaria]]''-like conifer ''[[Brachyphyllum]]''.<ref name=KC06>{{cite book |last=Carpenter |first=Kenneth |author-link=Kenneth Carpenter |year=2006 |chapter=Biggest of the big: a critical re-evaluation of the mega-sauropod ''Amphicoelias fragillimus'' |editor1=Foster, John R. |editor2=Lucas, Spencer G. |title=Paleontology and Geology of the Upper Jurassic Morrison Formation |series=New Mexico Museum of Natural History and Science Bulletin, '''36''' |publisher=New Mexico Museum of Natural History and Science |location=Albuquerque, New Mexico |pages=131–138 }}</ref> In Oklahoma, Stovall unearthed a considerable number of ''[[Apatosaurus]]'' specimens, which may have represented possible prey for a large theropod like ''Saurophaganax''.

Bite marks on ''[[Allosaurus]]'' and ''[[Mymoorapelta]]'' remains were found among other bones with feeding traces in the Upper Jurassic Mygatt-Moore Quarry. Unlike the others, these have left striations that, when measured to determine denticle width, produced tooth and body size extrapolations greater than any known specimen of ''Allosaurus'' or ''[[Ceratosaurus]],'' the two large predators known for osteological remains from the quarry. The extrapolations are instead coherent either with an unusually large specimen of ''Allosaurus'', or a separate large taxon like ''[[Torvosaurus]]'' or ''Saurophaganax,'' both of which are not known from the quarry''.'' The result either increases the known diversity of the site based on ichnological evidence alone, or represents powerful evidence of cannibalism in ''Allosaurus''. Based on the position and nutrient value associated with the various skeletal elements with bite marks, it is predicted that while ''Mymoorapelta'' was either predated upon or scavenged shortly after death, ''Allosaurus'' was scavenged some time after death.<ref>{{Cite journal|last1=Drumheller|first1=Stephanie K.|last2=McHugh|first2=Julia B.|last3=Kane|first3=Miriam|last4=Riedel|first4=Anja|last5=D’Amore|first5=Domenic C.|date=May 27, 2020|title=High frequencies of theropod bite marks provide evidence for feeding, scavenging, and possible cannibalism in a stressed Late Jurassic ecosystem|journal=PLOS ONE|language=en|volume=15|issue=5|pages=e0233115|doi=10.1371/journal.pone.0233115|pmid=32459808|pmc=7252595|bibcode=2020PLoSO..1533115D|issn=1932-6203|doi-access=free}}</ref>


==References==
==References==
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{{Taxonbar|from=Q131216}}


[[Category:Allosaurids]]
[[Category:Saurischians]]
[[Category:Late Jurassic dinosaurs of North America]]
[[Category:Tithonian genera]]
⚫
[[Category:Tithonian life]]
[[Category:Dinosaurs of the Morrison Formation]]
[[Category:Dinosaurs of the Morrison Formation]]
[[Category:Paleontology in Oklahoma]]
[[Category:Paleontology in Oklahoma]]
[[Category:Fossil taxa described in 1995]]
[[Category:Fossil taxa described in 1995]]
[[Category:Apex predators]]
[[Category:Symbols of Oklahoma]]
[[Category:Symbols of Oklahoma]]
⚫
[[Category:Nomina dubia]]

Latest revision as of 06:28, 30 December 2024

"Saurophagus maximus" redirects here. For the bird, see Saurophagus.

Saurophaganax
Temporal range: Late Jurassic
Kimmeridgian
Holotype specimen, a dorsal neural arch
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: incertae sedis
Genus: †Saurophaganax
Chure, 1995
Species:
†S. maximus
Binomial name
†Saurophaganax maximus
Chure, 1995
Synonyms

Saurophaganax ("lord of lizard-eaters") is a dubious, chimeric genus of large saurischian dinosaur, possibly a sauropod, from the Late Jurassic (Kimmeridgian) Morrison Formation of Oklahoma, United States. This taxon was historically considered to represent a species of Allosaurus or very large allosaurid. However, re-examinations of the attributed specimens suggested that it is a chimera of multiple dinosaur genera, since some specimens most likely belong to a diplodocid sauropod, while the other referred specimens could be reassigned to a novel species of Allosaurus.

Discovery and naming

[edit]
A drawer of vertebrae historically assigned to Saurophaganax, Oklahoma Museum of Natural History

In 1931 and 1932, John Willis Stovall uncovered remains of a large theropod near Kenton in Cimarron County, Oklahoma in layers of the late Kimmeridgian. In 1941, these were named Saurophagus maximus by Stovall in an article by journalist Grace Ernestine Ray.[1] The generic name is derived from Greek σαυρος, sauros, "lizard", φάγειν, phagein, "to eat", with the compound meaning of "lizard eater". The specific epithet maximus means "the largest" in Latin. Because the naming article did not contain a description, the name remained a nomen nudum. In 1987, Spencer George Lucas erroneously made OMNH 4666, a tibia, the lectotype, unaware that Saurophagus was a nomen nudum.[2]

Later, it was discovered that the name Saurophagus was preoccupied: in 1831, it had already been given by William Swainson to a tyrant-flycatcher, an extant eater of taxonomically true lizards.[3] In 1995, Daniel Chure named a new genus Saurophaganax, adding Greek suffix -άναξ, anax which means "ruler", replacing the earlier informal name "Saurophagus"; he also found OMNH 4666 undiagnostic in relation to Allosaurus, so he chose OMNH 1123, a neural arch, as the holotype for Saurophaganax.[4][5] Much of the material informally named "Saurophagus maximus", namely those diagnostic elements that could be distinguished from Allosaurus, were referred to Saurophaganax maximus by Chure; they contain disarticulated bones of at least four individuals.[4]

In 2024, Danison and colleagues revised the referral of various specimens assigned to Saurophaganax maximus including the fragmentary holotype neural arch (OMNH 1123) based on their comparative analysis. They suggested that the holotype could not confidently be regarded as a theropod or sauropod, although the complex accessory laminae are more comparable to those of sauropods, especially some juvenile specimens of Apatosaurus. Some referred specimens more likely belong to diplodocids than the large Kenton 1 Quarry allosaurid. Since the holotype neural arch is so fragmentary, the researchers couldn't confidently refer it to a theropod or sauropod, so they considered Saurophaganax maximus to be a nomen dubium.[6]

Previously assigned allosaurid specimens

[edit]
Mounted skeletons showing Saurophaganax as an Allosaurus-like taxon attacking Apatosaurus sp., in Oklahoma Museum of Natural History. The latter dinosaur may be closer to the actual identity of Saurophaganax

The identification of the allosaurid elements referred to Saurophaganax was a matter of dispute. It has been described as its own genus,[4] or as a species of Allosaurus: Allosaurus maximus.[7] A review of basal tetanurans in 2004 and Carrano et al.'s comprehensive 2012 analysis of Tetanurae accepted Saurophaganax as a distinct genus.[8][9] Possible Saurophaganax material from New Mexico may clear up the status of the genus.[10] In 2019, Rauhut and colleagues noted that the definitive taxonomic placement of Saurophaganax within Allosauroidea is unstable, being recovered as a sister taxon of Metriacanthosauridae or Allosauria, or even as a basalmost carcharodontosaurian.[11] Re-evaluation of the assigned specimens in a 2024 reassessment suggested that the referred allosaurid specimens belong to a novel species of Allosaurus, named as Allosaurus anax.[6]

Paleoenvironment

[edit]

The Morrison Formation is a sequence of shallow marine and alluvial sediments which, according to radiometric dating, ranges between 156.3 million years old (Ma) at its base,[12] to 146.8 million years old at the top,[13] which places it in the late Oxfordian, Kimmeridgian, and early Tithonian stages of the Late Jurassic period. This formation is interpreted as a semiarid environment with distinct wet and dry seasons. The Morrison Basin where dinosaurs lived, stretched from New Mexico to Alberta and Saskatchewan, and was formed when the precursors to the Front Range of the Rocky Mountains started pushing up to the west. The deposits from their east-facing drainage basins were carried by streams and rivers and deposited in swampy lowlands, lakes, river channels and floodplains.[14] This formation is similar in age to the Solnhofen Limestone Formation in Germany and the Tendaguru Formation in Tanzania. The fossils known of Saurophaganax (both the possible material from New Mexico and the Oklahoma material) are known from the Brushy Basin Member, which is the latest part of the Morrison Formation, suggesting that this genus was either always uncommon or that it first appeared rather late in the Jurassic. Because of the rarity of discovered remains, not much about its behavior is known.[15]

The Morrison Formation records an environment and time dominated by gigantic sauropod dinosaurs such as Barosaurus, Apatosaurus, Brontosaurus, Camarasaurus, Diplodocus, and Brachiosaurus. Dinosaurs that lived alongside Saurophaganax included the herbivorous ornithischians Camptosaurus, Dryosaurus, Stegosaurus, and Nanosaurus. Predators in this paleoenvironment included the theropods Torvosaurus, Ceratosaurus, Marshosaurus, Stokesosaurus, Ornitholestes, and[16] Allosaurus, which accounted for 70 to 75% of theropod specimens and was at the top trophic level of the Morrison food web.[17] Other vertebrates that shared this paleoenvironment included ray-finned fishes, frogs such as Eobatrachus, salamanders, turtles, sphenodonts, lizards, terrestrial and aquatic crocodylomorphs like Goniopholis, and several species of pterosaur like Kepodactylus. Early mammals were present in this region, such as Fruitafossor, docodonts, multituberculates, symmetrodonts, and triconodonts. The flora of the period has been revealed by fossils of green algae, fungi, mosses, horsetails, cycads, ginkgoes, and several families of conifers. Vegetation varied from river-lining forests of tree ferns, and ferns (gallery forests), to fern savannas with occasional trees such as the Araucaria-like conifer Brachyphyllum.[18]

References

[edit]
  1. ^ Ray, G.E., 1941, "Big for his day", Natural History 48: 36–39
  2. ^ Lucas, S.G., Mateer, N.J., Hunt, A.P., and O'Neill, F.M., 1987, "Dinosaurs, the age of the Fruitland and Kirtland Formations, and the Cretaceous-Tertiary boundary in the San Juan Basin, New Mexico", p. 35-50. In: Fassett, J.E. and Rigby, J.K., Jr. (eds.), The Cretaceous-Tertiary boundary in the San Juan and Raton Basins, New Mexico and Colorado. GSA Special Paper 209
  3. ^ W. Swainson and J. Richardson, 1831, Fauna boreali-americana, or, The zoology of the northern parts of British America: containing descriptions of the objects of natural history collected on the late northern land expeditions under command of Captain Sir John Franklin, R.N. Part 2, Birds, London, J. Murray
  4. ^ a b c Chure, Daniel J. (1995). "A reassessment of the gigantic theropod Saurophagus maximus from the Morrison Formation (Upper Jurassic) of Oklahoma, USA". In A. Sun; Y. Wang (eds.). Sixth Symposium on Mesozoic Terrestrial Ecosystems and Biota, Short Papers. Beijing: China Ocean Press. pp. 103–106.
  5. ^ Chure, D., 2000, A new species of Allosaurus from the Morrison Formation of Dinosaur National Monument (Utah-Colorado) and a revision of the theropod family Allosauridae. Ph.D. dissertation, Columbia University, pp. 1–964
  6. ^ a b Danison, Andrew; Wedel, Mathew; Barta, Daniel; Woodward, Holly; Flora, Holley; Lee, Andrew; Snively, Eric (December 21, 2024). "Chimerism in specimens referred to Saurophaganax maximus reveals a new species of Allosaurus (Dinosauria, Theropoda)". Vertebrate Anatomy Morphology Palaeontology. 12. doi:10.18435/vamp29404. ISSN 2292-1389.
  7. ^ Smith, David K. (1998). "A morphometric analysis of Allosaurus". Journal of Vertebrate Paleontology. 18 (1): 126–142. Bibcode:1998JVPal..18..126S. doi:10.1080/02724634.1998.10011039.
  8. ^ Holtz, Thomas R. Jr.; Molnar, Ralph E.; Currie, Philip J. (2004). Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (eds.). The Dinosauria (2nd ed.). Berkeley: University of California Press. pp. 71–110. ISBN 978-0-520-24209-8.
  9. ^ Carrano, Matthew T.; Benson, Roger B. J.; Sampson, Scott D. (June 1, 2012). "The phylogeny of Tetanurae (Dinosauria: Theropoda)". Journal of Systematic Palaeontology. 10 (2): 211–300. Bibcode:2012JSPal..10..211C. doi:10.1080/14772019.2011.630927. ISSN 1477-2019. S2CID 85354215.
  10. ^ Foster, John (2007). Jurassic West: the Dinosaurs of the Morrison Formation and Their World. Bloomington, Indiana:Indiana University Press. p. 117.
  11. ^ Rauhut, Oliver W. M.; Pol, Diego (December 11, 2019). "Probable basal allosauroid from the early Middle Jurassic Cañadón Asfalto Formation of Argentina highlights phylogenetic uncertainty in tetanuran theropod dinosaurs". Scientific Reports. 9 (1): 18826. doi:10.1038/s41598-019-53672-7. ISSN 2045-2322. PMC 6906444. PMID 31827108. Supplementary information
  12. ^ Trujillo, K.C.; Chamberlain, K.R.; Strickland, A. (2006). "Oxfordian U/Pb ages from SHRIMP analysis for the Upper Jurassic Morrison Formation of southeastern Wyoming with implications for biostratigraphic correlations". Geological Society of America Abstracts with Programs. 38 (6): 7.
  13. ^ Bilbey, S.A. (1998). "Cleveland-Lloyd Dinosaur Quarry – age, stratigraphy and depositional environments". In Carpenter, K.; Chure, D.; Kirkland, J.I. (eds.). The Morrison Formation: An Interdisciplinary Study. Modern Geology 22. Taylor and Francis Group. pp. 87–120. ISSN 0026-7775.
  14. ^ Russell, Dale A. (1989). An Odyssey in Time: Dinosaurs of North America. Minocqua, Wisconsin: NorthWord Press. pp. 64–70. ISBN 978-1-55971-038-1.
  15. ^ Foster, J. (2020). Jurassic West, Second Edition: The Dinosaurs of the Morrison Formation and Their World (Life of the Past). Indiana University Press. ISBN 9780253051578.
  16. ^ Foster, J. (2007). "Appendix." Jurassic West: The Dinosaurs of the Morrison Formation and Their World. Indiana University Press. pp. 327–329.
  17. ^ Foster, John R. (2003). Paleoecological Analysis of the Vertebrate Fauna of the Morrison Formation (Upper Jurassic), Rocky Mountain Region, U.S.A. New Mexico Museum of Natural History and Science Bulletin, 23. Albuquerque, New Mexico: New Mexico Museum of Natural History and Science. p. 29.
  18. ^ Carpenter, Kenneth (2006). "Biggest of the big: a critical re-evaluation of the mega-sauropod Amphicoelias fragillimus". In Foster, John R.; Lucas, Spencer G. (eds.). Paleontology and Geology of the Upper Jurassic Morrison Formation. New Mexico Museum of Natural History and Science Bulletin, 36. Albuquerque, New Mexico: New Mexico Museum of Natural History and Science. pp. 131–138.

Sources

[edit]
Wikimedia Commons has media related to Saurophaganax.
Wikispecies has information related to Saurophaganax.
  • Dixon, Dougal. The World Encyclopedia of Dinosaurs and Prehistoric Creatures.
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