The extinction of the dinosaurs was followed by the spread of grapes.

The end of the dinosaurs 66 million years ago led to the spread of plants such as grapevines. Fossil grapes ranging from 60 to 19 million years old have been discovered in Colombia, Panama and Peru..

One of the species included in the finds is the oldest known specimen of grapevines in the Western Hemisphereaccording to a study published in the journal Nature Plants.

“This is the oldest grape ever found in this part of the world, and it’s several million years younger than the oldest grape found on the other side of the planet,” said Fabiani Herrera, assistant curator of paleobotany at the Field Museum’s Negaunee Center for Integrative Studies in Chicago and lead author of the paper, in a statement. “This discovery is important because shows that after the extinction of the dinosaurs, grapes actually began to spread around the world“.

Soft tissues like fruits rarely fossilize, so scientists’ understanding of ancient fruits often relies on seeds, which are more likely to fossilize. The oldest known grape seed fossils were found in India and are 66 million years old.

The impact of asteroid on plants

It is no coincidence that grapes appeared in the fossil record 66 million years ago, around the time that a huge asteroid struck Earth, causing a mass extinction that changed the course of life on the planet. “We always think of animals, of dinosaurs, because they suffered the most, but The extinction event also had a huge impact on plants.“,” says Herrera. “The forest was restored in such a way that the composition of the plants changed.”

Herrera and his colleagues suggest that The extinction of dinosaurs may have helped change forests. “Large animals like dinosaurs are known to alter the ecosystems around them. “We thought that if there were large dinosaurs roaming the forest, they would probably cut down trees, effectively keeping the forests more open than they are today,” says Monica Carvalho, a co-author of the paper and an assistant curator at the University of Michigan Museum of Paleontology. But without large dinosaurs to prune them, some rainforests, including those in South America, became more crowded, with layers of trees forming understory and canopy. .

These dense new forests They provided an opportunity. “Around this time in the fossil record, we started seeing more plants that use vines to climb trees, like grapes,” Herrera says. The diversification of birds and mammals in the years after the mass extinction may have also helped grapes spread their seeds.

In 2013, Herrera’s thesis advisor and lead author of the new paper, Stephen Manchester, published a paper describing the oldest known grape seed fossil from India. Although Fossil grapes have never been found in South America.Herrera suspected they might be there too.

“Grapes have an extensive fossil record dating back to about 50 million years ago, so I wanted to find one in South America, but it was like looking for a needle in a haystack.”says Herrera. “I’ve been looking for the oldest grape in the Western Hemisphere since I was a student.”

But in 2022, Herrera and her co-author Monica Carvalho were conducting fieldwork in the Colombian Andes when they discovered a grape fossil in a 60-million-year-old rock. not only in the first grape fossil in South America, but also in one of the oldest grape fossils in the world.

The fossil seed is tiny, but Herrera and Carvalho were able to identify it based on its distinctive shape, size and other morphological characteristics. Back in the lab, they performed CT scans showing its internal structure, which confirmed its identity.

The team named the fossil Lithouva susmanii, or “Susman’s rock grape,” after Arthur T. Susman, a proponent of South American paleobotany at the Field Museum. “This new species is also important because it confirms a South American origin for the group in which the common Vitis vine evolved,” says co-author Gregory Stull of the National Museum of Natural History.

The team conducted additional field work in South and Central America, and in the Nature Plants paper, Herrera and his co-authors ultimately described nine new species of fossil grape varieties from Colombia, Panama and Peru that existed between 60 and 19 million years ago. These fossilized seeds tell not only the story of the spread of grapes throughout the Western Hemisphere, but also the numerous extinctions and expansions that this grape family has endured. The fossils are only distant relatives of grapes native to the Western Hemisphere, and some, such as the two species of Lia, are found today only in the Eastern Hemisphere.

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