Fossilised stomach contents of sauropod show what species ate

A groundbreaking Australian discovery has provided the first direct evidence of a sauropod’s* diet.

The fossilised* stomach contents from a 95-million-year-old Diamantinasaurus matildae* specimen*, nicknamed “Judy”, has offered a never before seen look into what these giant herbivores* ate.

The dino fossil was discovered in 2017 on a property near Winton in Queensland by Bob Elliott and excavated by the Australian Age of Dinosaurs Museum. The specimen was named in honour of the museum’s co-founder Judy Elliott.

An analysis of the stomach contents identified the specific plants Judy munched on, offering new understanding of the role that sauropods played in Cretaceous* ecosystems.

The research, led by Dr Stephen Poropat from Curtin University and published in Current Biology, shows that Judy had a wide diet of plant matter, including pinnules* and bracts* from towering conifers*, and leaves and fruiting bodies from seed ferns and early flowering plants.

In addition to the fossilised stomach contents, Dr Poropat and colleagues also examined mineralised* skin found with the specimen. This showed a pattern of polygonal* (often hexagonal) non-overlapping scales, a characteristic commonly seen in other sauropods.

Palaeontologists* have firmly believed since the late 19th century that sauropods were herbivores, Dr Poropat said.

“The specific plants that they ate, and the height above ground at which they fed, have remained unknown – until now,” Dr Poropat said.

“The stomach contents we found belonged to a 12-metre-long, subadult* sauropod that was still growing at the time of its death.”

“Our findings show that at least some species of subadult sauropods were able to feed at a range of heights above ground level, and consequently were equipped to deal with environmental and vegetation changes throughout the Jurassic* and Cretaceous periods.”

The research also confirms that sauropods were bulk feeders, similar to modern herbivorous reptiles and birds. Instead of chewing their food, they would have swallowed it whole, allowing their digestive system to break it down over time. A single meal would likely have stayed in their digestive tract for up to two weeks before coming out the other side.

John Curtin Distinguished Professor Kliti Grice, founding director of Curtin’s WA Organic and Isotope Geochemistry Centre and ARC Laureate Fellow, said the fossilised plant matter was able to be examined using advanced techniques.

“By using advanced organic geochemical* techniques, we were able to confirm the presence of both angiosperms* and gymnosperms* in the diet of this sauropod. This unique approach provided molecular evidence* of the plants that sauropods consumed,” Professor Grice said.

David Elliott OAM, co-founder and executive chairman of the Australian Age of Dinosaurs Museum, said, “Judy’s stomach contents and mineralised skin offer a unique insight into life during the Cretaceous Period in outback Queensland”.

“This discovery strengthens Winton’s reputation as one of the world’s most diverse dinosaur deposits* and reinforces the importance of continued fieldwork and research in this region,” he said.

According to Mr Elliott, the fossils of Judy, along with other important specimens, will help shape future research and exhibitions at the dedicated dinosaur museum.

“We are committed to preserving and showcasing these incredible discoveries, ensuring that Australia’s rich natural history is shared with the world,” he said.

The stomach contents and mineralised skin were preserved alongside yet-to-be-published body fossils of the subadult Diamantinasaurus, which are housed at the museum. These fossils will form a key part of the Australia Through Time exhibition at the Winton centre’s future multimillion-dollar natural history facility.

POLL

GLOSSARY

• sauropod: a group of four legged dinosaur that were very big and had long necks. They were also herbivores and were the largest animals to ever roam the Earth
• fossilised: the remains of a living creature left in a rock petrified over many years so that they leave an impression
• Diamantinasaurus matildae: a sauropod that lived in central Queensland about 94 million years ago in the Cretaceous period
• specimen: a sample of something
• herbivores: animals that eat a plant-based diet
• Cretaceous: the third and final period of the era when dinosaurs walked the Earth, about 145 to 66 million years ago
• pinnules: any of the smallest divisions of a leaf
• bracts: a specialised leaf that has a reproductive structure
• conifers: a type of tree characterised by needle-like leaves and pine cones
• mineralised: when minerals from the surrounding rocks seep into the pores of the skin and petrify the fossils turning it to stone and preserving its fine details
• polygonal: something with many sides or angles, anything with more than three sides is considered polygonal
• palaeontologists: scientists who study dinosaur fossils
• subadult: an animal that is not completely an adult yet
• Jurassic: the second period of the Mesozoic era, the era of dinosaurs, between the Triassic and Cretaceous periods
• organic geochemical: a scientific field that studies how living matter is transformed when stored within rocks and other geological matter
• angiosperms: flowering and/or fruiting plants
• gymnosperms: woody, perennial plants that bear seeds that are unprotected, like in the form of pine cones
• molecular evidence: evidence as seen in the DNA structure
• deposits: areas where fossils can be found

EXTRA READING
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QUICK QUIZ
1. The stomach contents of which type of dinosaur was analysed?
2. Where was the fossil discovered?
3. Why was it nicknamed Judy?
4. What is a herbivore?
5. Which prehistoric time period was the dinosaur from?

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CLASSROOM ACTIVITIES
1. Sauropod diet
Draw a diagram of a food chain for the Sauropod dinosaur.

Were Sauropods herbivores or carnivores? What is the difference between them?

What allows these researchers to gather this information on a creature 95 million years old?

Time: allow 15 minutes to complete this activity
Curriculum Links: English, Science, History, Personal and Social, Critical and Creative Thinking

2. Extension
Create an advertisement for the Australian Age of Dinosaurs Museum in Queensland encouraging tourists to visit.

australianageofdinosaurs.com/

Time: allow 15 minutes to complete this activity
Curriculum Links: English, Visual Arts, Personal and Social, Critical and Creative Thinking

VCOP ACTIVITY
BAB it!
Show you have read and understood the article by writing three sentences using the connectives “because’’, “and”, and “but” (BAB). Your sentences can share different facts or opinions, or the same ones but written about in different ways.