Did the Extinction of the Dinosaurs Pave the Way for Grapes?

Newly discovered fossils in South America hint at the evolution and proliferation of grapes around the world

Reddish-purple grape clusters hanging from a vine among green leaves
The grape family had a complex, tumultuous history of extinction and dispersal in Central and South America. Pexels

Whether fermented into wine, dried into raisins or eaten cold straight from the refrigerator, grapes are a delicious fruit that humans have enjoyed for thousands of years. Now, new research suggests the proliferation of these sweet, juicy orbs may be linked to the extinction of the dinosaurs.

After an asteroid struck Earth and wiped out the dinosaurs some 66 million years ago, the forests grew thicker and denser. The abundance of trees, in turn, allowed vining plants—including grapes—to thrive. In addition, as mammals and birds diversified following the mass extinction event, they may have helped spread grape seeds to new locations.

That’s the theory scientists spell out in a new paper in the journal Nature Plants. Their hypothesis is based on the discovery of fossilized grape seeds in Colombia, Panama and Peru that range from 19 million to 60 million years old. In the paper, scientists describe nine new species of grapes, including one that’s the oldest known grape in the Western Hemisphere.

Overall, ancient fruits can be difficult for scientists to study because their soft flesh decomposes quickly. Their hard seeds, however, were sometimes preserved as fossils.

In 2013, scientists described the world’s oldest known grape seed fossils, which had been found in India and were around 66 million years old. Their age lined up with the mass extinction event caused by an asteroid colliding with Earth.

That’s no coincidence, the scientists hypothesize. As dinosaurs traipsed around, their large bodies likely knocked down trees and kept the forests more open than they are today. When these hulking creatures disappeared, however, the forests became more crowded. To survive, plants had to compete with each other for sunlight and resources. Those that could climb, such as vines, had an advantage and blossomed.

“The history of the common grape has long, long roots, going back to right after the extinction of the dinosaurs,” says study co-author Fabiany Herrera, a paleobotanist at the Field Museum of Natural History in Chicago, to USA Today’s Claire Thornton. "It was only after the extinction of the dinosaurs that grapes started taking over the world."

Four panes showing CT scans and drawings of fossilized grape seeds
Scientists used CT scans (top) to understand the internal structures of the fossils. An artist also created a reconstruction of the fossilized seeds (bottom). Fabiany Herrera and Pollyanna von Knorring

Ancient grape seed fossils had never been discovered in South America, but scientists suspected they were there, so they decided to go looking for some. And their search was fruitful: They found nine new species, including one they named “Susman’s stone grape” (Lithouva susmanii) after Arthur T. Susman, who supports South American paleobotany at the Field Museum, according to a statement.

In addition to being the oldest grape ever found in the Western Hemisphere, Susman’s stone grape is important because it’s related to the subfamily Vitoideae, which gave rise to modern commercial grapes.

Together, the newly discovered fossils help paint a picture of the grape family’s trials and tribulations. Over time, some species of grapes went extinct in Central and South America, but adapted and survived elsewhere.

“What we’re seeing is this family has a complex history of extinction and dispersal in the New World,” says study co-author Mónica Carvalho, a paleobotanist at the University of Michigan, in a statement. “Various groups of this family, such as the genus Leea and species of tribe Cayrateae, only live today in Southeast Asia and the Indo-Pacific, but their fossils indicate that they lived in the New World for a very long time before becoming regionally extinct.”

Researchers don’t yet know why grapes went extinct in Central and South America but persisted in other parts of the world. But these tiny, humble fossils may offer a preview of what’s to come amid human-caused climate change.

“I only hope that most living plant seeds adapt quickly to the current climate crisis,” Herrera tells CNN’s Ashley Strickland. “The fossil record of seeds is telling us that plants are resilient but can also completely disappear from an entire continent.”

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