Diamantinasaurus matildae was a sauropod dinosaur that lived in what is now northeastern Australia during the Late Cretaceous, about 94 million years ago.
It was either part of an early evolutionary branch of the titanosaurs, or at least very closely related to them.
Growing up to around 15m long (~50′), it’s represented by multiple specimens of varying ages, including one of the most complete individual necks of any sauropod. Unlike later-diverging titanosaurs it still had thumb claws on its hands, and it’s unclear if it had any osteoderm armor.
A patch of preserved skin shows polygonal scales with a rough bumpy surface texture — but based on what’s now known from other types of sauropod it probably had a variety of other scale shapes and sizes across different regions of its body.
Recent discoveries of titanosaurian footprints in Mongolia also suggest that the large claws on these sauropods’ hind feet were mostly buried in soft tissue, with only the tips visible in life.
Fossilized gut contents in one specimen indicate Diamantinasaurus was a generalist herbivore eating a wide range of plant species, browsing from low to high foliage heights, and swallowing its bites without chewing. This particular individual wasn’t fully grown, however, and so it may have been in the process of transitioning from a low-level “juvenile” diet to a higher-level “adult” one.
References:
- Bell, Phil R., et al. “Remarkable soft tissue anatomy recorded in titanosaur (Sauropoda) tracks from the latest Cretaceous of Mongolia.” Zoological Journal of the Linnean Society 204.3 (2025): zlaf053. https://doi.org/10.1093/zoolinnean/zlaf053
- Gallagher, Tess, Jason Poole, and Jason P. Schein. “Evidence of integumentary scale diversity in the late Jurassic sauropod Diplodocus sp. from the Mother’s Day Quarry, Montana.” PeerJ 9 (2021): e11202. https://doi.org/10.7717/peerj.11202
- Poropat, Stephen F., et al. “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 (2023): 221618. https://doi.org/10.1098/rsos.221618
- Poropat, Stephen F., et al. “Fossilized gut contents elucidate the feeding habits of sauropod dinosaurs.” Current Biology 35.11 (2025): 2597-2613. https://doi.org/10.1016/j.cub.2025.04.053
- Taylor, Michael P. “Almost all known sauropod necks are incomplete and distorted.” PeerJ 10 (2022): e12810. https://doi.org/10.7717/peerj.12810
- Wikipedia contributors. “Diamantinasaurus” Wikipedia, 30 Oct. 2025, https://en.wikipedia.org/wiki/Diamantinasaurus