Photo of a tooth of Giraffatitan from Tanzania (Museum für Naturkunde Berlin, MB.R.2180.20.5). The wear surface on the tip of the tooth is clearly visible. Credit: Jan Kersten, Freie Universität Berlin, Fachrichtung Paläontologie.
Analysis of the dental wear on sauropods has revealed not only what the biggest dinosaurs ate but also provides a picture of the ecosystems they lived in 150 million years ago.
Sauropods were long-necked, herbivorous dinosaurs and the largest animals to ever walk on land. Some of the biggest, called titanosaurs, may have reached 40m in length and 70–100 tonnes.
How these creatures reached such colossal sizes has been a longstanding mystery in palaeontology.
New research, published in Nature Ecology and Evolution, analyses microscopic enamel wear marks on sauropod tooth fossils to try and answer these and other questions about how the lumbering herbivores lived during the Jurassic period, between 201 and 145 million years ago (mya).
“I still find it fascinating that microscopic scratches on fossil teeth can tell us so much about diet and even behaviour,” says corresponding author Daniela Winkler, a researcher at Kiel University in Germany.
The team analysed 322 high-resolution 3D scans of teeth found from 3 fossil sites: Lourinhã Formation in Portugal, the Morrison Formation in the US, and the Tendaguru Formation in Tanzania.
The teeth came from 39 individual sauropods.
“We’re talking about structures at the micrometre (a millionth of a metre) scale,” Winkler says. “These tiny wear marks result from the interaction between tooth and food – they reveal what the animals had eaten in the last days or weeks of their lives.”
Flagellicaudatan – a group of long-tailed sauropods which includes Diplodocus – teeth showed variable wear patterns. This suggests species in this group were generalist feeders.
Specimens of Camarasaurus from both Portugal and the US had very uniform wear patterns. This suggests the dinosaurs sought out the same preferred food sources throughout the year – a behaviour which could be explained by migration.
“The climate at the time in both Portugal and the US was highly seasonal, so certain plants likely weren’t available year-round,” explains corresponding Emanuel Tschopp a visiting researcher at the Leibniz Institute for the Analysis of Biodiversity Change and Freie Universität Berlin, also in Germany. “The consistency in Camarasaurus tooth wear suggests they may have migrated seasonally to access the same resources.”
“The sauropods of the Morrison Formation show enormous species diversity – and that diversity was only possible because the species behaved differently and occupied different dietary niches,” Tschopp adds.
Titanosaurs from Tanzania had intense and complex wear, suggesting specific environmental conditions.
The Tendaguru Formation during the Jurassic had a tropical to semi-arid climate. It was near a large desert belt so it’s possible that windswept sands could have been blown onto the plants these sauropods ate, leaving deep wear marks on their teeth.
“One of the most interesting aspects of this work is that we were able to relate differences in dental wear patterns to palaeogeography and the habitat preferences of different sauropod faunas,” adds co-author André Saleiro, a PhD student at NOVA University in Lisbon, Portugal.
Tschopp says the research shows how microscopic wear patterns can bring animals which have been dead for 150 million years to life.
“With these microscopic traces, we can suddenly make behavioural statements about these enormous extinct animals. Migration, specialisation, niche use – it all becomes tangible,” he says.
Exemplary teeth and 2D images of enamel wear patterns of the analyzed clades. Credit: Nature Ecology and Evolution (2025). DOI: 10.1038/s41559-025-02794-5.
And the researchers say that the analysis can be applied to more ancient teeth.
“What excites me is that we can keep refining this method – and every new sample adds another piece to the puzzle,” says Winkler. “Our tools are getting better – and so is our understanding of what life back then was really like.”
“We’re still at the beginning with this method,” Tschopp adds. “But combining palaeontology, modern technology and interdisciplinary collaboration opens up fascinating insights into ancient worlds.”