Stony Brook University professor part of team to find new dinosaur species

On tiny Spurwing Island in northern Zimbabwe, a Stony Brook University vertebrate paleobiologist and her colleagues have discovered a new species of dinosaur that lived about 210 million years ago.

The long-necked plant-eater, estimated to have weighed about 850 pounds, was a sauropodomorph from the Late Triassic epoch. Its kind gave rise to the brontosaurus and other sauropods, the largest animals to walk the earth, some of which weighed dozens of tons. It is only the fourth dinosaur species to be named from Zimbabwe and the first species to be discovered there in half a century, researchers said.

Kimberley Chapelle, an assistant professor at Stony Brook’s Renaissance School of Medicine, along with Paul Barrett of Britain’s Natural History Museum and others named their discovery Musankwa sanyatiensis. Musankwa was the name of the vessel they used to do their research and the Sanyati was the river whose original course is now submerged in the Sanyati Basin of Lake Kariba, where Spurwing Island is located.

They published their findings in May in the journal Acta Palaeontologica Polonica. Barrett was lead author.

In an interview, Chapelle said the find demonstrated the potential of field work in “undersampled” areas not frequented by paleontologists, as well as the need for greater understanding of the earth’s biodiversity at a critical point in prehistoric time. Roughly 200 million years ago — geologically, just a blink of the eye after Chapelle’s Musankwa perished — the end-Trissic extinction event killed off about three quarters of all species of life on the planet.

“Most likely this was linked to the separation of continents, which creates volcanic activity, with gasses and lava seeping out of the ground,” Chapelle said. “It causes havoc,” though dinosaurs — including the sauropodomorphs — flourished, she said. “It allows them to take over the landscape.”

The Musankwa was likely close to 20 feet long, a bipedal with two short, weak arms, Chapelle said. At a time when the world’s landmass was one supercontinent, it was similar to other sauropodomorphs found as far away as present-day South America and Antarctica.

Its environment was drier and hotter than present-day Zimbabwe, with seasonally overflowing rivers. With less vegetation than today — and no grass at all, because it hadn’t evolved yet — Musankwa probably ate a diet of cycads, ginkgo and tree ferns.

Researchers were unable to determine Musankwa’s gender and there was not enough fossil evidence to draw conclusions about herding or nesting behavior, as scientists have done with some dinosaurs, Chapelle said.

J. Bret Bennington, a professor of geology at Hofstra University who was not associated with the project, said the find was significant because it’s “giving us new data about how the whole family of dinosaurs started.”

While the body of knowledge about dinosaurs living 70 million years ago is relatively rich, “you go back in time and there’s less and less information to work with,” he said. The sedimentary rock where fossils are found “is destroyed, it’s eroded, it’s turned into metamorphic rock.”

Island-hopping on Lake Kariba, the world’s largest artificial lake by volume, made for difficult but rewarding fieldwork, said Chappelle, who was with Barrett when he discovered part of Musankwa’s fossilized leg — femur, tibia and part of an ankle — in 2018.

There was no “Eureka!” moment at the dig, she said, because it took years to do the work needed to confirm they’d discovered a new species, including removing rock from the fossil in the lab, conferring with colleagues and performing uranium-lead dating.