A new giant sauropod, Australotitan cooperensis gen. et sp. nov., from the mid-Cretaceous of Australia

June 08, 2021

Scott A. Hocknull (1,2), Melville Wilkinson (3), Rochelle A. Lawrence (1), Vladislav Konstantinov, Stuart Mackenzie (3), Robyn Mackenzie (3)
PeerJ, June 2021. DOI: 10.7717/peerj.11317


Titanosauria; Cretaceous; Winton Formation; New species; 3-D modelling; Fossil; Dinosaur; Sauropoda; Australia


A new giant sauropod, Australotitan cooperensis gen. et sp. nov., represents the first record of dinosaurs from the southern-central Winton Formation of the Eromanga Basin, Australia ... The new titanosaurian is the largest dinosaur from Australia as represented by osteological remains and based on limb-size comparisons it reached a size similar to that of the giant titanosaurians from South America. Using 3-D surface scan models we compare features of the appendicular skeleton that differentiate Australotitan cooperensis gen. et sp. nov. as a new taxon. A key limitation to the study of sauropods is the inability to easily and directly compare specimens. Therefore, 3-D cybertypes have become a more standard way to undertake direct comparative assessments. Uncoloured, low resolution, and uncharacterized 3-D surface models can lead to misinterpretations, in particular identification of pre-, syn- and post-depositional distortion. We propose a method for identifying, documenting and illustrating these distortions directly onto the 3-D geometric surface of the models using a colour reference scheme. This new method is repeatable for researchers when observing and documenting specimens including taphonomic alterations and geometric differences. A detailed comparative and preliminary computational phylogenetic assessment supports a shared ancestry for all four Winton Formation taxa, albeit with limited statistical support. Palaeobiogeographical interpretations from these resultant phylogenetic hypotheses remain equivocal due to contrary Asian and South American relationships with the Australian taxa. Temporal and palaeoenvironmental differences between the northern and southern-central sauropod locations are considered to explain the taxonomic and morphological diversity of sauropods from the Winton Formation. Interpretations for this diversity are explored, including an eco-morphocline and/or chronocline across newly developed terrestrial environments as the basin fills.

How Our Software Was Used

Dragonfly was used to align and process CT data and for 3D image rendering.

Author Affiliation

(1) Geosciences, Queensland Museum, Hendra, Brisbane City, Australia.
(2) Biosciences, University of Melbourne, Melbourne, Victoria, Australia.
(3) Eromanga Natural History Museum, Eromanga, Queensland, Australia.