First Fossil Proof Found That Long-Necked Dinosaurs Were Vegetarians

New York Times

09-06-2025

In the movie 'Jurassic Park,' a character proclaims there is nothing to fear from a towering Brachiosaurus, because it's a 'veggie-saurus' that eats only plants. Littlefoot, the 'Longneck' dinosaur in the 'Land Before Time' series, chows down on leaves, or 'tree stars.' But while pop culture and general scientific opinion have agreed for decades that the long-necked sauropod dinosaurs were herbivores, there was no definitive proof found in the fossil record.
But there were hints of a diet full of green stuff.
Fossils of sauropods, which stomped across the planet for 130 million years, are plentiful; additionally, herbivores tend to outnumber those of carnivores. The animals had small, peg-like teeth, and their huge, lumbering bodies seemed ill-equipped to chase down prey. 'Plants were pretty much the only option,' said Stephen Poropat, a paleontologist and the deputy director of the Western Australian Organic and Isotope Geochemistry Center at Curtin University in Perth.
A study published Monday in the journal Current Biology provides what may be the first concrete proof to support this argument, in the form of fossilized plants discovered in the belly of a sauropod. 'It's the smoking gun, or the steaming guts, as it were — the actual direct evidence in the belly of the beast,' Dr. Poropat said. 'It's never been found before for a sauropod dinosaur.'
Dr. Poropat, along with scientists and volunteers from the Australian Age of Dinosaurs Museum in Corfield, encountered the fossil, which is at the heart of their new paper, on a dig in the Winton Formation in Queensland, Australia, in 2017. The team was excavating a 36-foot-long juvenile Diamantinasaurus matildae, nicknamed Judy after the museum's co-founder Judy Elliott, when the scientists spotted something strange: a layer of fossilized plant material near the sauropod's pelvis.
'We knew we'd found something exceptional,' Dr. Poropat said, but he was hesitant to jump to conclusions. Fossilized gut contents, called cololites, are rare, especially from plant-eating dinosaurs, whose leafy diets don't preserve as well as the bones preserved in the bellies of carnivores.
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