How the death of the dinosaurs allowed grapes to flourish

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Grapes have been intertwined with human history for thousands of years. Wine made by our ancestors A new study reveals that this might not have happened if dinosaurs hadn’t vanished from the face of the earth thousands of years ago.

When an asteroid struck Earth 66 million years ago, it wiped out the giant, lumbering animals, setting the stage for other organisms and plants to thrive.

The discovery of grape fossils dating back 19 to 60 million years ago in Colombia, Panama and Peru is shedding light on how the unassuming fruit took hold in Earth’s dense forests and eventually colonized the planet.One of the newly discovered seeds is the oldest known example of a grape plant found in the Western Hemisphere, according to a study of the specimen published in the journal Nature on Monday. Natural plants.

“These are the oldest grapes ever found in this region, millions of years newer than the oldest found on the other side of the world,” Fabiani Herrera, assistant curator of paleobotany at the Field Museum at the Negaunee Integrated Research Center in Chicago and lead author of the study, said in a statement. “This discovery is important because it shows that grapes really began to spread around the world after the dinosaurs went extinct.”

Like soft animal tissues, actual fruits don’t preserve well in the fossil record, but seeds, which fossilize easily, could help scientists understand what plants were present at different stages in Earth’s history as they reconstruct the tree of life and establish origin stories.

The oldest grape seed fossils ever found were unearthed in India and date back 66 million years, around the time the dinosaurs went extinct.

“We always think about animals, about dinosaurs, because they were the ones most affected, but the extinction also had a big impact on plants,” Herrera says. “Forests reset themselves in a way that changed the composition of their plants.”

Herrera’s supervisor, Stephen Manchester, the study’s lead author, recently published a paper on grape fossils found in India, which sparked Herrera’s suspicions that grape seed fossils might exist in other places, such as South America, where no grape seed fossils had been found until now.

“I was hoping to find grapes in South America because grapes have an extensive fossil record that begins about 50 million years ago, but it was like looking for a needle in a haystack,” Herrera says. “I’ve been looking for the oldest grapes in the Western Hemisphere since I was an undergraduate.”

Herrera and Monica Carvalho, assistant curator at the University of Michigan Museum of Paleontology and co-author of the study, were doing fieldwork in the Colombian Andes in 2022 when Carvalho discovered the fossil. It turned out to be a 60-million-year-old grape seed fossil trapped in rock, making it one of the oldest fossils in the world and the first to be found in South America.

“She looked at me and said, ‘Fabianie, grapes!’ And I looked at it and I was like, ‘Oh my God.’ I was so excited,” Herrera said.

Although the fossil was small, its shape, size, and other characteristics led the pair to identify it as a grape seed. Returning to the lab, the researchers performed a CT scan to examine its internal structure, confirming their discovery.

The team named the newly discovered species Lituvata sasmani, meaning “Sussman’s stone grape,” in honor of Arthur T. Sussman, the Field Museum’s director of South American paleobotany.

“This new species is also important because it confirms the South American origin of the group from which the common grapevine, Vitis, evolved,” said study co-author Gregory Staal of the National Museum of Natural History.

The rocks were deposited in ancient lakes, rivers and coastal areas, Herrera said.

“I broke up every rock I could get my hands on in the field looking for these tiny seeds,” he said, adding that the arduous search “is the fun part of my job as a paleobotanist.”

Encouraged by this discovery, the team conducted further field work in South and Central America, where they discovered nine new fossil grape seed species trapped in sedimentary rocks. By tracing the lineage of the ancient seeds to modern grape seeds, the team realized there was something about what allowed the plant to thrive and spread.

The team hypothesized that when the dinosaurs became extinct, their absence changed the entire structure of the forest.

“Large animals like dinosaurs are known to alter the ecosystems around them, so if they roamed forests, they would likely have cut down trees, maintaining forests that were more open than they are today,” Carvalho said.

After the dinosaurs went extinct, tropical forests grew thick, with layers of trees forming scrubland and canopies. These dense forests made it difficult for plants to receive light, so they had to compete with each other for resources. And vines had an advantage, which they exploited to reach the canopy, the researchers said.

“The fossil record shows that around this time we began to see an increase in plants that used vines to climb trees, like grapes,” Herrera says.

After the extinction of the dinosaurs, a wide variety of birds and mammals began to inhabit the Earth, and they likely also contributed to the spread of grape seeds.

Studying the seeds can show how the grapevine spread, adapted and went extinct over millennia, demonstrating the grapevine’s resilience to survive in other parts of the world despite its disappearance from Central and South America over time.

Some fossils are related to modern grapes, while others are distant relatives of grapes native to the Western Hemisphere. For example, some fossil species can be traced back to grapes now found only in Asia and Africa, but it’s unclear why the grapes became extinct in Central and South America, Herrera said.

“The new fossil species tell a turbulent and complex history,” he said. “We usually think of diverse modern rainforests as a ‘museum’ model, where all the species accumulate over time. But our study shows that extinction was a major driver of rainforest evolution. Now we need to identify the causes of extinctions over the past 60 million years.”

Herrera hopes to find other examples of fossil plants, such as sunflowers, orchids and pineapples, to see if they were present in ancient tropical forests.

Studying the origins and adaptations of plants in the past is helping scientists understand what conditions plants may face in the event of a climate crisis.

“I can only hope that most living plant seeds will adapt quickly to the current climate crisis. The fossil seed record tells us that plants are resilient, but can also disappear completely from entire continents,” Herrera said.