View source for Muttaburrasaurus

{{Short description|Extinct genus of dinosaur from Queensland}}
{{use dmy dates|date=May 2024}} 
{{use Australian English|date=May 2024}} 
{{speciesbox
| name             = ''Muttaburrasaurus''
| fossil_range     = [[Early Cretaceous]] ([[Albian]]),<ref name="Holtz2008"/> {{fossilrange|112|103}}
| image            = Muttaburrasaurus mount.jpg
| image_caption    = Mounted skeleton
| display_parents  = 2
| genus            = Muttaburrasaurus
| parent_authority = Bartholomai & [[Ralph Molnar|Molnar]], [[1981 in paleontology|1981]]
| species          = langdoni
| authority        = Bartholomai & Molnar, 1981
}}

'''''Muttaburrasaurus''''' was a [[genus]] of [[herbivorous]] [[iguanodontia]]n [[ornithopod]] [[dinosaur]] that lived in what is now northeastern [[Australia]] sometime between 112 and 103 [[million years ago]]<ref name="Holtz2008">Holtz, Thomas R. Jr. (2012) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages,'' [http://www.geol.umd.edu/~tholtz/dinoappendix/HoltzappendixWinter2011.pdf Winter 2011 Appendix.]</ref> during the early [[Cretaceous]] [[Period (geology)|period]]. It has been recovered in some analyses as a member of the iguanodontian clade [[Rhabdodontomorpha]].<ref name="McDonald">{{cite journal |last1=McDonald |first1=Andrew T. |last2=Kirkland |first2=James I. |last3=DeBlieux |first3=Donald D. |last4=Madsen |first4=Scott K. |last5=Cavin |first5=Jennifer |last6=Milner |first6=Andrew R. C. |last7=Panzarin |first7=Lukas |year=2010 |editor-last=Farke |editor-first=Andrew Allen |title=New Basal Iguanodonts from the Cedar Mountain Formation of Utah and the Evolution of Thumb-Spiked Dinosaurs |journal=PLOS ONE |volume=5 |issue=11 |page=e14075 |bibcode=2010PLoSO...514075M |doi=10.1371/journal.pone.0014075 |pmc=2989904 |pmid=21124919 |doi-access=free}}</ref> After ''[[Kunbarrasaurus]]'', it is Australia's most completely known dinosaur from skeletal remains. It was named after [[Muttaburra]], the site in [[Queensland]], Australia, where it was found. The dinosaur was selected from twelve candidates to become the [[Symbols of Queensland|official fossil emblem]] of the State of Queensland.<ref>{{cite web |title=Queensland's new State fossil emblem |url=https://www.qld.gov.au/about/newsroom/queensland-state-fossil-emblem |website=Queensland Government |publisher=The State of Queensland |access-date=7 April 2023}}</ref><ref>{{cite web |title=The dinosaur Queenslanders dig |url=https://statements.qld.gov.au/statements/96403 |website=Media Statements |publisher=The State of Queensland |access-date=7 April 2023 |date=22 October 2022}}</ref>

==Discovery==
[[File:Muttaburrasaurus skull.jpg|thumb|left|[[Holotype]] skull]]
The species was initially described from a partial skeleton found by grazier Doug Langdon in 1963 at Rosebery Downs Station beside [[Thomson River (Queensland)|Thomson River]] near [[Muttaburra]], in the Australian [[States and territories of Australia|state]] of [[Queensland]], which also provides the creature's generic name. The remains were collected by [[paleontologist]] Dr [[Alan Bartholomai]] and [[entomologist]] Edward Dahms. After a lengthy preparation of the fossils, it was named in 1981 by Bartholomai and [[Ralph Molnar]], who honoured its discoverer with its [[specific name (zoology)|specific name]], ''langdoni''.<ref>{{cite journal |last1=Bartholomai |first1=Alan |author-link1=Alan Bartholomai |last2=Molnar |first2=R.E. |author-link2=Ralph Molnar |name-list-style=and |year=1981 |title=''Muttaburrasaurus'': a new Iguanodontid (Ornithischia:Ornithopoda) dinosaur from the Lower Cretaceous of Queensland |url=https://www.biodiversitylibrary.org/item/188348#page/93/mode/1up |journal=Memoirs of the Queensland Museum |volume=20 |issue=2 |pages=319–349}}</ref>

The [[holotype]], specimen QM F6140, was found in the [[Mackunda Formation]] dating to the [[Albian]]-[[Cenomanian]]. It consists of a partial skeleton with skull and lower jaws. The underside of the skull and the back of the [[mandibula]], numerous vertebrae, parts of the pelvis, and parts of the front and hind limbs have been preserved.

Some teeth have been discovered further north, near [[Hughenden, Queensland|Hughenden]],<ref name="Molnar96">{{cite journal |last=Molnar |first=Ralph E. |author-link=Ralph Molnar |year=1996 |title=Observations on the Australian ornithopod dinosaur, ''Muttaburrasaurus''". |url=https://www.biodiversitylibrary.org/item/123909#page/151/mode/1up |journal=Memoirs of the Queensland Museum |volume=39 |issue=3 |pages=639–652}}</ref> and south at [[Lightning Ridge, New South Wales|Lightning Ridge]],<ref name="Molnar96"/> in northwestern [[New South Wales]]. At Lightning Ridge, there have been found [[opal]]ised teeth and a [[scapula]] that may be from a ''Muttaburrasaurus''. A skull, known as the "Dunluce Skull", specimen QM F14921, was discovered by John Stewart-Moore and 14-year-old Robert Walker on Dunluce Station, between Hughenden and [[Richmond, Queensland|Richmond]] in 1987. It originates from somewhat older layers of the [[Allaru Formation|Allaru]] [[Mudstone]] and was considered by Molnar to be a separate, yet unnamed species, a ''Muttaburrasaurus'' sp.<ref name="Molnar96"/> The same area produced two fragmentary skeletons in 1989. There have also been isolated teeth and bones found at Iona Station, southeast of Hughenden.

Reconstructed skeleton casts of ''Muttaburrasaurus'', sponsored by [[Kellogg's|Kellogg Company]], have been put on display at a number of museums, including the [[Queensland Museum]], [[Flinders Discovery Centre]], and [[National Dinosaur Museum]] in Australia.

==Description==
[[File:Muttaburrasaurus Scale.svg|thumb|left|Scale comparison with human]]
''Muttaburrasaurus'' was about {{convert|8|m}} and weighed around {{convert|2.8|MT|ST}}.<ref>{{cite book |last=Paul |first=G.S. |author-link=Gregory S. Paul |title=The Princeton Field Guide to Dinosaurs |publisher=[[Princeton University Press]] |year=2010 |page=286}}</ref> The [[femur]] of the holotype has a length of {{convert|1015|mm}}.
[[Image:Muttaburrasaurus NT.jpg|thumb|right|[[Life restoration]]]]
Whether ''Muttaburrasaurus'' is capable of quadrupedal movement has been debated; it was originally thought to be an "iguanodontid", though recent studies indicate a rhabdodont position. Ornithopods this basal were incapable of quadrupedal movement. Originally reconstructing ''Muttaburrasaurus'' with a thumb spike, Molnar later doubted such a structure was present.<ref name="Molnar96"/> The foot was long and broad, with four toes.

The skull of ''Muttaburrasaurus'' was rather flat, with a triangular cross-section when seen from above; the back of the head is broad but the snout pointed. The snout includes a strongly enlarged, hollow, upward-bulging nasal muzzle that might have been used to produce distinctive calls or for display purposes. However, as no fossilised nasal tissue has been found, this remains conjectural. This so-called ''bulla nasalis'' was shorter in the older ''Muttaburrasaurus'' sp., as is shown by the Dunluce Skull. The top section of the ''bulla'' of the holotype has not been preserved, but at least the second skull has a rounded profile.<ref name="Molnar96"/>

==Classification==
[[File:Muttaburrasaurus langdoni TMAG 20171118-036.jpg|thumb|right|Reconstructed skull]]
Molnar originally assigned ''Muttaburrasaurus'' to the [[Iguanodontidae]]. Later authors suggested more [[basal (phylogenetics)|basal]] euornithopod groups such as the [[Camptosauridae]], [[Dryosauridae]], or [[Hypsilophodont]]idae. Studies by Andrew McDonald indicate a position in the [[Rhabdodontidae]].<ref name=McDonald/><ref name=McDonaldUpdate>{{Cite journal |last=McDonald |first=Andrew T. |editor-last=Farke |editor-first=Andrew A. |title=Phylogeny of Basal Iguanodonts (Dinosauria: Ornithischia): An Update |doi=10.1371/journal.pone.0036745 |journal=PLOS ONE |volume=7 |issue=5 |pages=e36745 |year=2012 |pmid=22629328 |pmc=3358318 |bibcode=2012PLoSO...736745M |doi-access=free }}</ref> A 2022 phylogenetic analysis recovered ''Muttaburrasaurus'' and ''[[Tenontosaurus]]'' as basal rhabdodontomorphs and found them to likely represent sister taxa to Rhabdodontidae.<ref>{{cite journal |last=Poole |first=Karen E. |date=25 October 2022 |title=Phylogeny of iguanodontian dinosaurs and the evolution of quadrupedality |url=https://palaeo-electronica.org/content/2022/3707-iguanodontian-phylogeny |journal=[[Palaeontologia Electronica]] |volume=25 |issue=3 |doi=10.26879/702 |access-date=25 February 2023|doi-access=free }}</ref>

The following cladogram was recovered by Dieudonné and colleagues in 2016:<ref>{{Cite journal |last1=Dieudonné |first1=Paul-Emile |last2=Tortosa |first2=Thierry |last3=Torcida Fernández-Baldor |first3=Fidel |last4=Canudo |first4=José Ignacio |last5=Díaz-Martínez |first5=Ignacio |date=2016-06-22 |editor-last=Farke |editor-first=Andrew A. |title=An Unexpected Early Rhabdodontid from Europe (Lower Cretaceous of Salas de los Infantes, Burgos Province, Spain) and a Re-Examination of Basal Iguanodontian Relationships |journal=PLOS ONE |language=en |volume=11 |issue=6 |pages=e0156251 |doi=10.1371/journal.pone.0156251 |issn=1932-6203 |pmc=4917257 |pmid=27333279 |bibcode=2016PLoSO..1156251D |doi-access=free }}</ref>

{{clade| style=font-size:85%;line-height:85%
|label1=[[Iguanodontia]]
|1={{clade
   |1={{clade
      |1=''[[Anabisetia]]''
      |2={{clade
         |1=''[[Tenontosaurus]]''
         |2=[[Dryomorpha]] }} }}
   |label2=[[Rhabdodontomorpha]]
   |2={{clade
      |1='''''Muttaburrasaurus'''''
      |2={{clade
         |1=Vegagete Ornithopod
         |label2=[[Rhabdodontidae]]
         |2={{clade
            |1=''[[Mochlodon]]''
            |2={{clade
               |1=''[[Rhabdodon]]''
               |2=''[[Zalmoxes]]'' }} }} }} }} }} }}

However, in 2024, Fonseca and colleagues considered ''Muttaburrasaurus'' to be outside Rhabdodontomorpha and instead classified it as a member of the Gondwanan clade [[Elasmaria]], alongside ''[[Fostoria dhimbangunmal]]''.<ref>{{Cite journal |last1=Fonseca |first1=André O. |last2=Reid |first2=Iain J. |last3=Venner |first3=Alexander |last4=Duncan |first4=Ruairidh J. |last5=Garcia |first5=Mauricio S. |last6=Müller |first6=Rodrigo T. |date=December 2024 |title=A comprehensive phylogenetic analysis on early ornithischian evolution |journal=Journal of Systematic Palaeontology |volume=22 |issue=1 |at=2346577 |bibcode=2024JSPal..2246577F |doi=10.1080/14772019.2024.2346577}}</ref>

==Palaeobiology==
[[File:Hughenden-dinosaur-outback-queensland-australia.JPG|thumb|Statue in [[Hughenden, Queensland]], Australia]]
''Muttaburrasaurus'' had very powerful jaws equipped with shearing [[teeth]]. Whereas in more derived [[ornithopod]] species, the replacement teeth alternated with the previous tooth generation to form a tooth battery, in ''Muttaburrasaurus'', they grew directly under them, and only a single erupted generation was present, thus precluding a chewing motion. An additional basal trait was the lack of a primary ridge on the teeth sides, which show eleven lower ridges. In 1981, Molnar speculated that these qualities indicated an [[omnivorous]] diet, implying that ''Muttaburrasaurus'' occasionally ate carrion. In 1995, he changed his opinion, suspecting that ''Muttaburrasaurus''{{'}}s dental system is evolutionarily convergent with the [[ceratopsia]]n system of shearing teeth. They would have been an adaptation for eating tough vegetation such as [[cycad]]s.<ref>{{cite conference |last=Molnar |first=R.E. |author-link=Ralph Molnar |year=1995 |editor1-last=Sun |editor1-first=A. |editor2-last=Wang |editor2-first=Y. |title=Possible convergence in the jaw mechanisms of ceratopians and ''Muttaburrasaurus'' |conference=Sixth Symposium on Mesozoic Terrestrial Ecosystems and Biota, short papers |location=Beijing |publisher=China Ocean Press |pages=115–117}}</ref>

== References ==
{{Reflist}}

== Further reading ==
{{Commons category|Muttaburrasaurus}}

* {{cite journal |last=Cannon |first=Libby |year=2006 |title=The Muttaburra Lizard |journal=Australian Age of Dinosaurs |issue=4 |pages=16–31}}


{{Ornithopoda|O.}}
{{Taxonbar|from=Q131170}}
{{Portal bar|Dinosaurs|Paleontology|Australia}}

[[Category:Elasmaria]]
[[Category:Dinosaur genera]]
[[Category:Albian dinosaurs]]
[[Category:Fossil taxa described in 1981]]
[[Category:Taxa named by Ralph Molnar]]
[[Category:Dinosaurs of Australia]]