Fossil Analysis Reveals Early Presence of Fruit-Bearing Plants in the Late Cretaceous

Over 74 million years ago, fruit-bearing plants thrived in Cretaceous ecosystems, challenging previous assumptions about the evolution of flowering plants, according to a study published in Science on June 25. Researchers led by paleoecologist Jaemin Lee of the University of California, Berkeley, analyzed 450 fossilized diaspores—structures that include fruits and seeds—from a volcanic ash layer in New Mexico, revealing a diversity of winged seeds and fleshy, berry-like fruits as large as small dates.

What Do the Fossils Reveal?

The study’s findings overturn the long-held belief that flowering plants (angiosperms) relied primarily on wind for seed dispersal before the Cretaceous-Paleogene extinction event 66 million years ago. Instead, the diaspores—some with winged adaptations and others resembling modern berries—suggest that angiosperms had already developed complex seed dispersal strategies involving animals. “These fossils indicate that large, fleshy fruits were common long before the mass extinction,” Lee said. “This challenges the idea that angiosperms only diversified after dinosaurs disappeared.”

Among the 80 distinct diaspore shapes identified, more than a third featured fleshy textures, a trait associated with animal-driven seed dispersal today. Brian Atkinson, a paleobiologist at the University of Kansas not involved in the study, noted that such diversity “was previously thought to be rare in the Late Cretaceous.” The research also aligns with evidence of angiosperm leaf and growth form evolution during the period, suggesting reproductive structures adapted in tandem with plant specialization.

How Did Dinosaurs Influence Plant Evolution?

The presence of fleshy fruits implies that Cretaceous animals, including pterosaurs, early mammals, and birds, may have consumed these plants. Fossilized dung containing diaspores, discovered in prior studies, supports this theory, though identifying the exact animals remains challenging. “Matching poops to their extinct producers can be tricky,” Lee acknowledged. However, the similarity between ancient diaspores and modern fruits strongly suggests that Cretaceous fauna played a role in spreading angiosperm seeds.

Selena Smith, a paleobotanist at the University of Michigan, emphasized the significance of the findings: “It makes sense that reproductive structures evolved alongside plant efficiency. This study adds to a growing body of evidence that angiosperms were already dominant in certain ecosystems before the dinosaur extinction.”

Why Does This Matter for Paleontology?

The discovery reshapes understanding of prehistoric ecosystems. Angiosperms, which now dominate global forests, appear to have established their ecological foothold during a time when dinosaurs still roamed. “These plants were already shaping their environments through complex interactions with animals,” Smith said. The study also highlights the need for further research at other Late Cretaceous sites to confirm whether these fruits were widespread or localized phenomena.

As researchers continue to analyze fossil records, the interplay between plant evolution and animal behavior during the Cretaceous period remains a critical area of inquiry. “This work opens new questions about how ecosystems functioned before the mass extinction,” Atkinson said. “It’s a reminder that life’s adaptations are often more complex than we assume.”