Recently, in a groundbreaking discovery published in the journal Nature Plants, researchers unearthed fossilized grape seeds that range from 60 to 19 million years old in Colombia, Panama, and Peru.
Among these findings, one species represents the earliest known example of plants from the grape family in the Western Hemisphere. These ancient seeds provide critical insights into how the grape family proliferated in the aftermath of the dinosaurs‘ demise.
“These are the oldest grapes ever found in this part of the world, and they’re a few million years younger than the oldest ones ever found on the other side of the planet,” says Fabiany Herrera, an assistant curator of paleobotany at the Field Museum in Chicago’s Negaunee Integrative Research Center and the lead author of the Nature Plants paper. “This discovery is important because it shows that after the extinction of the dinosaurs, grapes really started to spread across the world.”
The preservation of soft tissues like fruits as fossils is exceedingly rare, leaving scientists to glean insights from fossilized seeds, which have a higher likelihood of enduring over time. The oldest known grape seed fossils, dating back 66 million years, were discovered in India. The timing of these grape fossils aligns with a significant event in Earth’s history – a catastrophic asteroid impact that led to the mass extinction of the dinosaurs and reshaped life on our planet.
Paleobotanist Herrera has dedicated years to unraveling the mysteries of ancient fruits through the study of tiny seed fossils.
Unearthing evidence of ancient fruits is no easy task, as the soft fruits themselves do not fossilize. This makes the search for seeds a crucial aspect of the investigation.
Remarkably, grape seeds have a well-documented fossil history spanning over 50 million years. Notably, the discovery of 66 million-year-old grape seed fossils in India coincides with the catastrophic asteroid impact that forever altered Earth’s history.
Driven by a strong intuition, Herrera has long suspected the existence of grapes in South America millions of years ago. After years of unwavering dedication, Herrera’s persistence has finally borne fruit: his team has unearthed grape seeds in rocks dating back 60 million years.
The extinction events also have an impact on plants, according to the researchers. They suggest that the disappearance of the dinosaurs may have spurred changes in the forest.
“Large animals, such as dinosaurs, are known to alter their surrounding ecosystems. We think that if there were large dinosaurs roaming through the forest, they were likely knocking down trees, effectively maintaining forests more open than they are today,” says Mónica Carvalho, a co-author of the paper.
The absence of large herbivores in South American tropical forests is believed to have contributed to their increased density. Without dinosaurs feeding on and knocking down trees, the forests developed a thicker understory and extensive canopy layer, creating opportunities for various plant species to flourish.
The woodlands became an ideal environment for climbing vines such as grapes, aided by the role of ancient birds and mammals in spreading grape seeds far and wide.
“In the fossil record, we start to see more plants that use vines to climb up trees, like grapes, around this time,” says Herrera.
The ancient seeds were closely analyzed by the researchers using CT scans to uncover their internal structure. Analysis of the fossils’ shape, dimensions, and other physical traits indicated that they were from a previously unknown grape species.
These recently found fossils act as miniature time capsules, preserving information about the history of grapes, including details about extinction events.
“The fossil record tells us that grapes are a very resilient order. They’re a group that has suffered a lot of extinction in the Central and South American region, but they also managed to adapt and survive in other parts of the world,” says Herrera in the press release.
Journal reference:
- Fabiany Herrera, Mónica R. Carvalho, Gregory W. Stull, Carlos Jaramillo & Steven R. Manchester. Cenozoic seeds of Vitaceae reveal a deep history of extinction and dispersal in the Neotropics. Nature Plants, 2024; DOI: 10.1038/s41477-024-01717-9