Open Paleo

Diamantinasaurus

Hocknull et al., 2009 DEE-a-man-TEE-nuh-SOR-us

From Diamantina River (near the discovery site in Queensland, Australia) + Greek sauros, 'lizard'; means 'Diamantina lizard'

113.2–89.8 million years ago Albian–Turonian, Early Cretaceous–Late Cretaceous
Early Cretaceous and Late Cretaceous stages

Diamantinasaurus is a genus of titanosaurian sauropod from Australia that lived during the early Late Cretaceous, about 94 million years ago. The type species of the genus is D. matildae, first described and named in 2009 by Scott Hocknull and colleagues based on fossil finds in the Winton Formation. Meaning "Diamantina lizard", the name is derived from the location of the nearby Diamantina River and the Greek word sauros, "lizard". The specific epithet is from the Australian song Waltzing Matilda, also the locality of the holotype and paratype. The known skeleton includes most of the forelimb, shoulder girdle, pelvis, hindlimb and ribs of the holotype, and one shoulder bone, a radius and some vertebrae of the paratype.

Diagnosis

  1. Humerus intermediate robusticity (autapomorphic); proximal breadth 50% of total length; distal condyles merged and flat extending only just onto anterior face of shaft.
  2. Metacarpal III phalange heavily reduced (autapomorphic).
  3. Femur intermediate robusticity (autapomorphic); distal condyles bevelled dorso-medially; shaft elliptical in cross-section and deflected medially.
  4. Tibia cnemial crest projects cranially then laterally (autapomorphic).
  5. Fibula intermediate robusticity (autapomorphic); distal articular surface bevelled cranio-medially.
  6. Crescentic-shaped sternal plate.

Species

Diamantinasaurus matildae Hocknull et al., 2009

Type species

Named for the Australian folk song 'Waltzing Matilda', written by Banjo Paterson in Winton, Queensland, near the type locality; the holotype specimen was nicknamed 'Matilda'.

Holotype
AODF 603 , Australian Age of Dinosaurs Fossil Museum of Natural History
Material
Right scapula, right and left humeri, right ulna, near complete right metacarpus including metacarpals II-V, phalanges and manus ungual. Left metacarpal I. Dorsal ribs and fragmentary gastralia. Left sternal plate. Left ilium and isolated sacral processes. Right and left pubes and ischia. Right femur, tibia, fibula and astragalus.
Horizon
upper Winton Formation, Albian–Turonian, Early Cretaceous–Late Cretaceous , 113.2–89.8 million years ago
Locality
Matilda Site, Elderslie Station, Queensland, Australia

Notable specimens

  • “Judy”

    AODF 888 Australian Age of Dinosaurs Fossil Museum of Natural History gut contents

    Referred subadult preserving the first known fossilized gut contents of any sauropod, plus skin with polygonal scales. The contents show bulk feeding and multi-level browsing on conifers, seed ferns and flowering plants.

    Poropat et al. (2025)

  • “Ann”

    AODF 906 Australian Age of Dinosaurs Fossil Museum of Natural History complementary

    Referred specimen preserving a much more complete skull, about 50 centimeters long, with numerous previously unknown cranial elements intact, greatly extending knowledge of the genus's cranial anatomy.

    Poropat et al. (2023)

  • “Oliver”

    AODF 663 Australian Age of Dinosaurs Fossil Museum of Natural History ontogeny

    Referred juvenile specimen of Diamantinasaurus, documenting an immature growth stage of the genus.

    Rigby et al. (2022)

References

  1. Poropat, S. F.; Kundrát, M.; Mannion, P. D.; Upchurch, P.; Tischler, T. R.; Elliott, D. A. (2021). Second specimen of the Late Cretaceous Australian sauropod dinosaur Diamantinasaurus matildae provides new anatomical information on the skull and neck of early titanosaurs. Zoological Journal of the Linnean Society 192: 610-674. doi:10.1093/zoolinnean/zlaa173

    Places both individuals, the type among them, in the "Cenomanian–lower Turonian 'upper' Winton Formation".

    poropat2021a
  2. Hocknull, S. A.; White, M. A.; Tischler, T. R.; Cook, A. G.; Calleja, N. D.; Sloan, T.; Elliott, D. A. (2009). New Mid-Cretaceous (Latest Albian) Dinosaurs from Winton, Queensland, Australia. PLoS ONE 4(7): e6190. Public Library of Science (PLoS). doi:10.1371/journal.pone.0006190 hocknull2009a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the hip height estimate.

    jones2026b
  4. Poropat, S. F.; Mannion, P. D.; Rigby, S. L.; Duncan, R. J.; Pentland, A. H.; Bevitt, J. J.; Sloan, T.; Elliott, D. A. (2023). A nearly complete skull of the sauropod dinosaur Diamantinasaurus matildae from the Upper Cretaceous Winton Formation of Australia and implications for the early evolution of titanosaurs. Royal Society Open Science 10(4): 221618. doi:10.1098/rsos.221618 poropat2023a
  5. Poropat, S. F.; Tosolini, A. M. P.; Beeston, S. L.; Enchelmaier, M. J.; Pentland, A. H.; Mannion, P. D.; Upchurch, P.; Chin, K.; Korasidis, V. A.; Bell, P. R.; Enriquez, N. J.; Holman, A. I.; Brosnan, L. M.; Elson, A. L.; Tripp, M.; Scarlett, A. G.; Godel, B.; Madden, R. H. C.; Rickard, W. D. A.; Bevitt, J. J.; Tischler, T. R.; Croxford, T. L. M.; Sloan, T.; Elliott, D. A.; Grice, K. (2025). Fossilized gut contents elucidate the feeding habits of sauropod dinosaurs. Current Biology 35(11): 2597-2613.e7. doi:10.1016/j.cub.2025.04.053 poropat2025a
  6. Rigby, S. L.; Poropat, S. F.; Mannion, P. D.; Pentland, A. H.; Sloan, T.; Rumbold, S. J.; Webster, C. B.; Elliott, D. A. (2022). A juvenile Diamantinasaurus matildae (Dinosauria: Titanosauria) from the Upper Cretaceous Winton Formation of Queensland, Australia, with implications for sauropod ontogeny. Journal of Vertebrate Paleontology 41(6): e2047991. doi:10.1080/02724634.2021.2047991 rigby2022a