A new study from the University of Auckland looks at animals' roles in moving seeds from one place to another. Evidence from fossils indicates that seeds consumed by dinosaurs could remain intact in their stomachs, suggesting a possible role in helping plants to spread in the prehistoric world.
That led Professor George Perry, of the School of Environment, to look at how far dinosaurs may have spread the seeds, by modeling the animals' likely travel speeds along with their likely frequency of defecation—both factors that can be estimated from body weight.
His work, which was announced on Thursday in the journal Biology Letters, suggests that an optimum seed spreader might have been a dinosaur such as Triceratops, which may have weighed eight to 10 tons and moved at a maximum speed of around 25 kilometers per hour. Triceratops is a genus of herbivorous ceratopsid dinosaur that first appeared during the late Cretaceous period, about 68 million years ago in what is now North America.
Another dinosaur of similar body mass and potential seed dispersal capacity was Stegosaurus, which may have weighed six to eight tons.
Stegosaurus is an herbivorous dinosaur that lived in the Jurassic period, between 155 and 150 million years ago, in the region currently known as the western United States. These dinosaurs may have spread seeds on average as far as 4 to 5 kilometers, and in rare cases, more than 30 kilometers.
In an article published on the website of the University of Auckland, Professor Perry points to the complex relationships of living things within ecosystems—a topic that's especially relevant as the world experiences what some scientists describe as the "sixth mass extinction."
"When we think about extinct animals, it's easy to just think of a long list—but in fact, they all played inter-linked roles in our ecosystems," he added.
Fossilized plants with features that suggest they may have been dispersed by animals date as far back as 280 million years—and seeds from fossilized gut contents are just as old. Dinosaurs went extinct about 65 million years ago.