Hubbry Logo
MuttaburrasaurusMuttaburrasaurusMain
Open search
Muttaburrasaurus
Community hub
Muttaburrasaurus
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Muttaburrasaurus
Muttaburrasaurus
Muttaburrasaurus
View on Wikipedia
from Wikipedia

Muttaburrasaurus
Temporal range: Early Cretaceous (Albian),[1] 112–103 Ma
Mounted skeleton
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Dinosauria
Clade: †Ornithischia
Clade: †Ornithopoda
Clade: †Rhabdodontomorpha
Genus: †Muttaburrasaurus
Bartholomai & Molnar, 1981
Species:
†M. langdoni
Binomial name
†Muttaburrasaurus langdoni
Bartholomai & Molnar, 1981

Muttaburrasaurus was a genus of herbivorous iguanodontian ornithopod dinosaur that lived in what is now northeastern Australia sometime between 112 and 103 million years ago[1] during the early Cretaceous period. It has been recovered in some analyses as a member of the iguanodontian clade Rhabdodontomorpha.[2] 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 official fossil emblem of the State of Queensland.[3][4]

Discovery

[edit]
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 near Muttaburra, in the Australian 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, langdoni.[5]

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,[6] and south at Lightning Ridge,[6] in northwestern New South Wales. At Lightning Ridge, there have been found opalised 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 in 1987. It originates from somewhat older layers of the Allaru Mudstone and was considered by Molnar to be a separate, yet unnamed species, a Muttaburrasaurus sp.[6] 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 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

[edit]
Scale comparison with human

Muttaburrasaurus was about 8 metres (26 ft) and weighed around 2.8 metric tons (3.1 short tons).[7] The femur of the holotype has a length of 1,015 millimetres (40.0 in).

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.[6] 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.[6]

Classification

[edit]
Reconstructed skull

Molnar originally assigned Muttaburrasaurus to the Iguanodontidae. Later authors suggested more basal euornithopod groups such as the Camptosauridae, Dryosauridae, or Hypsilophodontidae. Studies by Andrew McDonald indicate a position in the Rhabdodontidae.[2][8] A 2022 phylogenetic analysis recovered Muttaburrasaurus and Tenontosaurus as basal rhabdodontomorphs and found them to likely represent sister taxa to Rhabdodontidae.[9]

The following cladogram was recovered by Dieudonné and colleagues in 2016:[10]

Iguanodontia

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.[11]

Palaeobiology

[edit]
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 ceratopsian system of shearing teeth. They would have been an adaptation for eating tough vegetation such as cycads.[12]

References

[edit]

Further reading

[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Muttaburrasaurus

View on Grokipedia
from Grokipedia
Muttaburrasaurus is a of large herbivorous ornithopod dinosaur that lived during the period, approximately 110 to 100 million years ago, in what is now northeastern . Known primarily from and , it measured up to 7 meters in length, stood about 3 meters high at the hip, and weighed around 2,800 kilograms, making it one of the largest ornithopods recorded from the Australian continent. This dinosaur is classified within Iguanodontia, specifically as a basal iguanodontian or styracosternan, characterized by its bipedal or quadrupedal locomotion, with the ability to rear up on hind legs for browsing or speed. Its most distinctive feature is a rounded, bulbous containing hollow nasal chambers, which may have functioned for enhancing olfactory capabilities or producing resonant calls, though the exact purpose remains debated. The powerful jaws were equipped with shearing teeth suited for processing tough vegetation such as ferns, cycads, , and podocarps in forested environments near ancient inland seas. The genus was first discovered in 1963 near the town of Muttaburra in by local grazier Doug Langdon, with the (QM F6140) consisting of a nearly 60% complete skeleton from the Mackunda Formation (late to early stages). Formally named and described in 1981 by paleontologists Alan Bartholomai and Ralph E. Molnar as an iguanodontid, subsequent studies have refined its phylogenetic position while confirming additional specimens from sites like Hughenden and Lightning Ridge. Muttaburrasaurus langdoni remains one of the most complete dinosaur skeletons found in , providing key insights into the diverse ornithopod faunas of during the era.

Discovery and Naming

Initial Discovery

In 1963, grazier Doug Langdon discovered the first fossils of Muttaburrasaurus while mustering cattle on his property at Rosebery Downs Station, approximately 4.5 km southeast of Muttaburra in , . The bones were found along the banks of the Thomson River, eroding from the Mackunda Formation, a geological unit consisting of marine and paralic sediments from the stage of the period, dating to approximately 113–100 million years ago. The specimen, cataloged as QM F6140 at the Museum, comprises a partial that is nearly complete except for most of the ; it includes a well-preserved , several vertebrae, , and elements of the pectoral and pelvic girdles along with limb bones. Langdon promptly reported the find to the Museum, where the fossils were transported for initial assessment and safekeeping. At the , palaeontologist Ralph Molnar conducted a preliminary examination in the mid-1960s, identifying the remains as belonging to an ornithopod , specifically an iguanodontid, based on the dental and cranial features visible in the unprepared matrix. Preparation of the specimen, involving mechanical cleaning and acetic acid treatment, was a meticulous undertaken by museum staff over nearly two decades due to the delicate nature of the bones and limited resources at the time. This delay in full analysis meant there was no immediate formal publication following the discovery; the specimen was first briefly noted in museum records and regional geological surveys in the late . The comprehensive scientific description and naming of Muttaburrasaurus langdoni were not published until 1981, when Molnar collaborated with Alan Bartholomai to detail the anatomy and significance of the find in the Memoirs of the Queensland Museum.

Additional Specimens

In 1987, a nearly complete but crushed , known as the "Dunluce Skull" (QM F14921), was discovered on Dunluce Station near Hughenden in north-central , from the Allaru Mudstone of the Rolling Downs Group. This specimen, referred to Muttaburrasaurus sp., preserves details of the maxillary tooth rows, which are displaced about 3 cm apart due to postmortem crushing, and exhibits features such as a trend toward a continuous enamel sheet on the labial face of the maxillary , providing insights into cranial variation within the . The is considered older and more primitive than the 1963 from the nearby Mackunda Formation, supporting recognition of these materials as conspecific based on shared ornithopod characteristics. Opalised teeth from Lightning Ridge in northwestern , recovered from the Griman Creek Formation, have been tentatively referred to Muttaburrasaurus, including specimen QM F12541, which consists of parts of two dentary teeth in natural cast. These isolated dental elements suggest a more plesiomorphic form of the , indicating a broader geographic distribution across eastern during the and potentially representing a distinct species. An associated opalised from the same locality may also pertain to Muttaburrasaurus, further expanding the known postcranial range, though its referral remains provisional pending additional material. Additional isolated postcranial elements, including limb bones and vertebrae, have been identified from various sites in the , contributing to understandings of intraspecific variation in body proportions and locomotion. These referrals, primarily from the Winton and Mackunda formations, confirm morphological diversity within Muttaburrasaurus langdoni without altering the core of the .

Etymology and Significance

The genus name Muttaburrasaurus was erected in 1981 by paleontologists Alan Bartholomai and Ralph E. Molnar to describe the specimen (QM F6140), an incomplete but substantial skeleton discovered near the town of Muttaburra in , . The name derives from "Muttaburra," honoring the nearby township close to the type locality, combined with the Greek sauros meaning "lizard" or "reptile," thus translating to "Muttaburra lizard." The specific epithet langdoni commemorates Doug Langdon, the local grazier who found the fossils in 1963 while checking watering points on his property and promptly reported them to the Queensland Museum. In December 2023, M. langdoni was officially designated as the fossil emblem of by the state government, following a public poll where it emerged as the top choice among twelve candidates. This recognition, formalized through the Emblems of Queensland and Other Legislation Amendment Act 2023, highlights its role in promoting dinosaur tourism and paleontological heritage in outback . Scientifically, Muttaburrasaurus langdoni holds significance as one of 's most complete ornithopod skeletons, comprising approximately 60% of the individual and providing key insights into dinosaur anatomy in the region. As the only named large-bodied ornithopod from , it exemplifies the diversity of basal iguanodontians in Gondwanan ecosystems during the Aptian-Albian stages, contributing to understandings of dinosaur evolution. The and associated casts are prominently displayed at institutions such as the Queensland Museum, where they educate on 's prehistoric .

Physical Description

Cranial Anatomy

The of Muttaburrasaurus langdoni is flat and elongated, featuring a broad postorbital region where the height measures slightly more than half the maximum breadth, and lacking horns or frills. The specimen (QM F6140) preserves the in a slightly distorted and crushed condition, with bone loss in the posterodorsal, anterior, and right lateral areas. A defining characteristic is the prominent nasal bulla, an inflated and hollow expansion of the that forms a bulbous rising higher than the cranial roof and exhibiting a longitudinally sinuous lateral profile. This structure is evident in the and also present, though shorter, in the Dunluce (QM F14921), a referral specimen from slightly older strata. The and are robust, contributing to the overall solidity of the . The upper and lower jaws house a battery of shearing teeth suited to the ornithopod . The bears at least 18 teeth in a single row, each laterally compressed with 7–13 vertical ridges on the enamel, which is confined to the and lacks a central carina; replacement occurs in an alternating pattern. The dentary, incomplete anteriorly and ventrally, thickens posteriorly external to the tooth row and displays a sinusoidal ventral margin in dorsal view. The braincase includes a composed of a larger dorsal and smaller ventral , a supraoccipital bearing a median ridge, and a basioccipital that forms a rounded occipital condyle. Observations from the and Dunluce Skull indicate a robust quadrate that slopes posteriorly, with the exoccipital's paroccipital process lacking distal decline, and a broad post-infratemporal bar contributing to the skull's stability. Eye position appears dorsolateral, consistent with the ornithopod configuration for scanning for predators while feeding.

Postcranial Skeleton

The postcranial skeleton of Muttaburrasaurus is best known from the specimen QM F6140, a partial preserving elements of the axial and , supplemented by fragmentary remains from additional specimens such as QM F12541 and QM F14921. The vertebral column comprises approximately 9 , at least 15 dorsal vertebrae, 6 fused sacral vertebrae, and an extensive series of caudal vertebrae. are opisthocoelous, possess a prominent ventral , and are broader transversely than deep, while transition from amphiplatyan to mildly amphicoelous forms with a ventral on the anterior ones and decreasing length toward the mid-series; robust neural spines along the presacral column contribute to overall structural strength. Sacral centra are deeply constricted and robustly fused, and anterior caudal feature ventral pits, amphicoelous or amphiplatyan articular faces, and a squared profile that tapers posteriorly. The includes bifid-headed extending posteriorly from mid-cervical positions and strongly curved, double-headed dorsal ribs that expand anteroposteriorly at their distal ends, forming a broad, barrel-shaped indicative of a body form. The pectoral consists of a long, slender that is robust and thickened proximally with an expanded distal , paired with a small, deep featuring a thick articular facet for the , together providing a strong attachment for musculature. The pelvic girdle is similarly robust, with an ilium bearing a long anterior process comprising about two-fifths of its total length and six articulations with the , an elongate pubis with a thin, bladelike prepubic process, and proximal portions of the that are broad and deeply curved, supporting powerful propulsion. Forelimbs are shorter overall than hindlimbs, with the sigmoidal representing the longest element in the arm (heavier exceeding the in robustness); the manus preserves five digits, including manual digit V with at least three phalanges, but lacks a definitive spike. Hindlimbs feature a robust, curved as the longest in the with a massive , a sturdy shorter than the , and a slender articulating directly with the astragalus; the pes is tridactyl, supported by four metatarsals (with IV the longest) and robust phalanges. Postcranial elements from multiple specimens exhibit variations in robustness, particularly in proportions and thickness, consistent with facultative quadrupedality in basal iguanodontians where strong forelimbs enable occasional on all fours.

Size and Proportions

Muttaburrasaurus langdoni is estimated to have reached a total body length of 7 to 8 meters, with a of approximately 3 meters based on skeletal reconstructions of the and referred material. These dimensions position it as a medium- to large-sized ornithopod for its time and . Mass estimates derived from volumetric models of the skeletal frame, incorporating assumptions typical for ornithischians, range from 2.5 to 3 metric tons for adults. The proportions of the limbs reflect adaptations for a primarily bipedal posture, with significantly longer and more robust than the forelimbs, enabling efficient bipedal locomotion while retaining the ability for quadrupedal support during feeding or resting. The measured about 0.99 meters in length, while the reached 1.015 meters, underscoring the relative elongation of the elements. This configuration, with comprising roughly half the body length and forelimbs shorter by comparison, aligns with reconstructions emphasizing capabilities in open environments. Ontogenetic changes are inferred from additional specimens, including isolated elements and a referred (QM F14921), which exhibit smaller dimensions suggestive of subadult stages compared to the . These indicate rapid growth during the , potentially reaching adult size within a few years, consistent with histological patterns observed in related ornithopods. Scaled digital models from recent analyses confirm variability in adult body size.

Classification and Phylogeny

Historical Interpretations

Upon its formal description in 1981, Muttaburrasaurus langdoni was classified by Alan Bartholomai and E. Molnar as a member of the within , based primarily on postcranial features that aligned with Philip Dodson's (1980) diagnostic criteria for the family, including a constricted scapular blade, short , and a curved with a prominent lesser . The authors highlighted the dinosaur's large size and distinctive inflated nasal region, which formed a bulla-like structure, and drew comparisons to the cranial elaborations in Ouranosaurus nigeriensis, a recently described African iguanodontid with a similar sail-like nasal crest, suggesting toward more derived ornithopod morphologies. This placement positioned Muttaburrasaurus as an advanced ornithopod, potentially bridging iguanodontids and hadrosaurs, though the holotype's partial skull and incomplete postcrania limited finer distinctions. In the , subsequent revisions shifted Muttaburrasaurus toward a more basal position within Iguanodontia, informed by comparative analyses of and limb morphology. David B. Norman and David B. Weishampel (1990) incorporated it into their broad review of iguanodontids and related ornithopods, retaining an iguanodontian affinity but emphasizing primitive traits such as the leaf-shaped denticles on cheek teeth and relatively gracile proportions that suggested facultative quadrupedality rather than strict seen in more derived forms. Ralph E. Molnar's 1996 restudy, drawing on new fragmentary specimens from , further refined this view by noting the maxillary teeth's multiple low ridges and emerging continuous labial enamel sheet, indicative of adaptations for processing tough , while limb elements pointed to a divergence from the iguanodontian-hadrosaur lineage prior to and . These assessments underscored how the original iguanodontid label had overemphasized superficial resemblances in the limited material, favoring a basal iguanodontian status instead. Pre-2010 debates on Australian ornithopod often framed Muttaburrasaurus as emblematic of regional isolation, representing a "dryland" form adapted to arid inland environments amid Gondwana's fragmentation, distinct from the more diverse Laurasian iguanodontian radiations. Limited material from eastern reinforced perceptions of an endemic lineage, with Muttaburrasaurus's robust build and dental specializations interpreted as responses to isolated continental conditions, potentially limiting with northern relatives. This view persisted despite ongoing discussions of vicariance versus dispersal, highlighting the as a key Gondwanan holdover until broader phylogenetic frameworks later challenged such isolation narratives.

Phylogenetic Position

In 2010, Andrew T. McDonald and colleagues positioned Muttaburrasaurus as a non-hadrosaurid iguanodontian within , a of basal ornithopods characterized by derived dental and cranial features but lacking advanced hadrosaurid traits. This placement marked an early recognition of its affinities to European rhabdodontids like Rhabdodon, distinguishing it from more derived iguanodontids. Earlier interpretations linking Muttaburrasaurus to traditional iguanodontids have since been considered outdated due to refined phylogenetic matrices. Subsequent analyses have largely supported this basal position within Iguanodontia. In a study, Karen E. employed expanded morphological datasets with 398 characters across 75 taxa, recovering Muttaburrasaurus as a basal rhabdodontomorph in a alongside Tenontosaurus and Rhabdodontidae, supported by moderate parsimony and Bayesian metrics (jackknife support of 62%). This analysis emphasized its placement outside Styracosterna (the hadrosaurid lineage), reinforcing as a Gondwanan-Laurasian group with shared occlusal adaptations. A 2024 phylogenetic analysis by André O. Fonseca and coauthors, utilizing a comprehensive matrix of 500+ characters from early ornithischians, proposed an alternative placement for Muttaburrasaurus within Elasmaria, a uniting South American and Australian non-dryomorph ornithopods such as Talenkauen and Dilobosaurus. This positioning, derived from maximum parsimony (consistency index 0.42), highlights Gondwanan endemism and is bolstered by shared postcranial traits, including robust ilial peduncles and a medially directed pubis. Key character states underpinning these positions include a shearing with leaf-shaped teeth bearing prominent primary ridges for precise occlusion, the absence of an enlarged thumb spike (unlike in ), and a propubic pelvic with a pronounced prepubis process indicative of basal iguanodontian morphology. These features collectively support Muttaburrasaurus as an early-diverging iguanodontian, though ongoing debates reflect matrix-dependent resolutions between and Elasmaria. Muttaburrasaurus is classified within , a of basal iguanodontians, where it serves as the sister taxon to the more derived Rhabdodontidae, sharing features such as a prominent nasal boss and robust postcranial elements adapted for facultative . Within this group, it exhibits close affinities to other Gondwanan forms like Fostoria dhimbangunmal from , which shares iliac morphology and dental wear patterns indicative of similar herbivorous adaptations. Sister taxa in the related Elasmaria, primarily known from , include Talenkauen santacrucensis and Macrogryphosaurus gondwanicus from , with which Muttaburrasaurus shares a hollow nasal bulla potentially used for vocalization and a incipient dental battery for efficient foliage processing. These shared traits underscore a Gondwanan radiation of non-hadrosaurid ornithopods during the , distinct from lineages. Broader connections extend to other Gondwanan ornithopods such as Gasparinisaura cincosaltensis from , which displays comparable femoral proportions and pedal morphology, suggesting vicariance-driven isolation of Australasian forms like Muttaburrasaurus from South American relatives following the breakup of . This isolation is evident in the endemic Australian ornithopod assemblage, where taxa like Fostoria reinforce regional without direct Laurasian influences. In contrast to Laurasian iguanodonts, Muttaburrasaurus lacks the enlarged thumb spike characteristic of bernissartensis, instead featuring a more generalized manual phalangeal formula suited to browsing rather than defensive piercing. Similarly, it differs from advanced hadrosaurs in possessing a simpler nasal structure without the elaborate hollow crests for acoustic display seen in genera like . Early taxonomic debates considered potential synonymy of Muttaburrasaurus with other fragmentary Australian ornithopods, such as unnamed forms from the , but phylogenetic analyses in the 2020s have resolved it as a distinct species based on unique cranial and humeral autapomorphies.

Paleoecology and Biology

Geological Setting

The fossils of Muttaburrasaurus are primarily known from the Mackunda Formation in , Australia, dating to the late Albian stage of the period, approximately 105 million years ago. This formation, equivalent to the Allaru Formation in northern regions, comprises marine-influenced fluvial deposits, including sandstones, siltstones, and mudstones that indicate deposition on coastal floodplains adjacent to the advancing Eromanga Sea. of detrital zircons and stratigraphic correlations constrain the upper portions of the Mackunda Formation to between 104 and 102 million years ago, aligning with a broader range of 112–103 Ma for related units in eastern . The paleoenvironment of the Mackunda Formation was characterized by warm, humid conditions with seasonal river systems draining into nearshore settings, supporting a landscape of low-relief floodplains interspersed with channels and occasional marine incursions. assemblages from the formation reveal a dominated by araucarian , ferns, cycads, and emerging angiosperms, indicative of forested coastal plains with periodic wet-dry cycles influenced by monsoonal climates. This depositional regime occurred amid the tectonic rifting of from , which promoted basin subsidence and sediment accumulation in the Eromanga Basin. Additional Muttaburrasaurus material has been reported from the Griman Creek Formation in , representing slightly younger deposits around 100 million years ago, with paleoenvironments of arid woodlands along low-energy fluvial and lacustrine systems, as evidenced by interlaminated fine-grained sediments and opalized remains. Co-occurring in these formations includes the sauropod Austrosaurus in marine-influenced equivalents.

Diet and Feeding Adaptations

Muttaburrasaurus was a herbivorous , with its diet primarily consisting of tough, fibrous vegetation such as ferns, cycads, club-mosses, and podocarps that were abundant in its Australian habitat. This inference is drawn from the regional preserved in coeval deposits and the dinosaur's cranial adaptations suited for processing such . The teeth of Muttaburrasaurus exhibit specialized morphology for shearing tough plant material, featuring leaf-shaped crowns with diamond-shaped lateral faces and prominent ridges that facilitated slicing and grinding. These teeth were tightly packed in the jaws, forming continuous shearing blades along the dental rows, unlike the alternating replacement teeth seen in more derived ornithopods. The dental structure, including asymmetrical crowns with enamel on the lingual side, supported a herbivorous feeding strategy focused on cropping and pulverizing fibrous foliage. Jaw mechanics in Muttaburrasaurus indicate a robust system capable of transverse grinding motions, enabled by pleurokinetic skull joints and enlarged adductor musculature that provided high mechanical leverage. This configuration allowed for a powerful palinal (backward) and transverse power stroke, similar to that in ceratopsians, representing a case of in dental batteries and function for processing abrasive . The robust , with a lowered relative to the tooth row, enhanced bite efficiency for shearing tough plants. As a facultatively bipedal reaching up to 7 meters in length, Muttaburrasaurus could adopt a bipedal stance to browse at heights of approximately 4 meters, accessing mid-canopy foliage while quadrupedal locomotion facilitated low-level feeding on understory . This versatility in posture complemented its cranial adaptations, enabling exploitation of diverse plant resources in forested or riparian environments.

Locomotion and Inferred Behavior

Muttaburrasaurus langdoni exhibited an indeterminate locomotor habit, with skeletal evidence suggesting it was capable of both bipedal and quadrupedal postures. The relative lengths and strengths of its fore- and hindlimbs indicate that it could adopt a quadrupedal stance, particularly for stability while feeding on low vegetation, while its longer hindlimbs supported bipedal progression for faster movement or evasion. The femur displays high obliquity with a laterally bowed shaft and a wide-gauge stance, features that may have facilitated static bipedalism for reaching higher resources or defensive posturing, similar to patterns observed in some basal ornithopods. The robust postcranial skeleton, including strong limb bones and a bulky body build, implies adaptations for withstanding physical confrontations, potentially aiding in defense against contemporaneous predators such as in its Australian habitat. A distinctive hollow nasal bulla on the snout, formed by expanded , has been hypothesized to support visual or auditory displays within social groups, though no preserved confirms this function. This structure's position and form resemble those in other iguanodontians used for intraspecific signaling, suggesting possible gregarious behavior for foraging or reproduction.

References

  1. https://australian.museum/learn/dinosaurs/fact-sheets/muttaburrasaurus-langdoni/
  2. https://artsandculture.google.com/story/muttaburrasaurus-langdoni-one-of-the-most-complete-dinosaur-fossils-in-australia-queensland-museum-network/1wVxcqvKpqpQLg?hl=en
  3. https://www.nhm.ac.uk/discover/dino-directory/muttaburrasaurus.html
  4. https://pmc.ncbi.nlm.nih.gov/articles/PMC6284429/
  5. https://dinosaurs.group.uq.edu.au/files/2131/Angolin_et_al_2010.pdf
  6. https://www.abc.net.au/news/2013-12-19/muttaburrasaurus-doug-langdon-fossil-reunion-brisbane-museum/5167272
  7. https://www.biodiversitylibrary.org/part/303872
  8. https://artsandculture.google.com/story/muttaburrasaurus-langdoni-one-of-the-most-complete-dinosaur-fossils-in-australia-queensland-museum-network/1wVxcqvKpqpQLg
  9. https://biostor.org/reference/260396
  10. https://www.biodiversitylibrary.org/item/188348#page/7/mode/1up
  11. https://www.qld.gov.au/about/how-government-works/flags-emblems-icons/fossil-emblem
  12. https://statements.qld.gov.au/statements/99251
  13. https://zenodo.org/records/16092608/files/bhlpart154562.pdf?download=1
  14. https://archive.org/details/biostor-260396
  15. https://www.biodiversitylibrary.org/item/188348
  16. https://www.biodiversitylibrary.org/item/123909
  17. https://www.australianageofdinosaurs.com/page/86/australian-age-of-dinosaurs-muttaburrasaurus-langdoni
  18. http://museum.wa.gov.au/explore/dinosaur-discovery/muttaburrasaurus
  19. https://pup-assets.s3.amazonaws.com/public/resources/9780691231570/The-Princeton-Field-Guide-to-Dinosaurs-3rd-ed-mass-table-v2.docx
  20. https://utoronto.scholaris.ca/bitstreams/d600fdd7-8c6e-4324-b913-7e4fa45660e4/download
  21. https://www.cambridge.org/core/journals/paleobiology/article/relationships-of-mass-properties-and-body-proportions-to-locomotor-habit-in-terrestrial-archosauria/879681AEE82881881EDBEA1D24A2B794
  22. http://gspauldino.com/Revisedtaxonomy.pdf
  23. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0014075
  24. https://palaeo-electronica.org/content/pdfs/702.pdf
  25. https://pmc.ncbi.nlm.nih.gov/articles/PMC8667728/
  26. https://www.researchgate.net/publication/343081673_A_new_phylogeny_of_cerapodan_dinosaurs
  27. https://www.tandfonline.com/doi/abs/10.1080/14772019.2019.1582562
  28. https://www.tandfonline.com/doi/abs/10.1080/14772019.2024.2346577
  29. https://peerj.com/articles/12362.pdf
  30. https://peerj.com/articles/5513/
  31. https://www.sciencedirect.com/science/article/abs/pii/S0037073817301240
  32. https://search.informit.org/doi/pdf/10.3316/informit.T2025073000016001350832321
  33. https://anatomypubs.onlinelibrary.wiley.com/doi/abs/10.1002/ar.24283
  34. https://anatomypubs.onlinelibrary.wiley.com/doi/am-pdf/10.1002/ar.24283
  35. https://onlinelibrary.wiley.com/doi/pdf/10.1111/pala.70016
  36. https://search.informit.org/doi/pdf/10.3316/informit.T2025093000001801433359476
Add your contribution
Related Hubs
User Avatar
No comments yet.