Flowering plants may have recruited dinosaurs long before birds or mammals, with hundreds of fossil fruits revealing an ancient seed-spreading strategy

The next time you pop a blueberry in your mouth, think about this: the fleshy fruits we eat today may partly exist because of dinosaurs. A stunning trove of fossils from New Mexico suggests that flowering plants were already making big, animal-friendly fruits tens of millions of years earlier than scientists thought and that prehistoric creatures, perhaps even dinosaurs, were likely helping to spread those seeds around the ancient forests.

A new 2026 study, titled ‘Diversification of angiosperm reproductive strategies predated the end-Cretaceous extinction,’ was published in Science by paleoecologist Jaemin Lee and colleagues at the University of California, Berkeley. The team analyzed 450 fossil diaspores from volcanic ash in south-central New Mexico, findings that could challenge decades of scientific consensus. The fossils, collected from the site from 1992 to 2016, date to about 74.6 million years ago.

A snapshot frozen in ash
The New Mexico deposit, known as Dori’s Tuff, is within the Jose Creek Formation and is nearly a mile in length. The Science study reveals that a volcanic ashfall, at one moment in time, buried an entire inland forest, preserving leaves, flowers, and seeds just as they fell, giving the site the nickname “botanical Pompeii.” UC Berkeley professor Cindy Looy, a co-author, notes that most fossil plant sites are a jumble of material that drifted into rivers or lakes over time. This place is different; it offers a real snapshot.

The team catalogued diaspores in almost 80 different shapes. Some were built with wings to ride the wind. More than a third were pulpy. The largest were about the size of a small date. And the average size, comparable to a large blueberry, was a more than thousandfold increase in volume over the typical Cretaceous plant fossils, where the average diaspore was no larger than a poppy seed. The fossilized forest was composed of large-trunked flowering trees that included relatives of laurel and palms, along with ferns and redwoods.

The old theory and why it's now under scrutiny
For many generations, scientists have believed that flowering plants, or angiosperms, played a relatively minor role in reproduction until the dinosaurs became extinct. The seminal 2000 study by Eriksson, Friis, and Löfgren in The American Naturalist, ‘Seed size, fruit size, and dispersal systems in angiosperms from the Early Cretaceous to the Late Tertiary,’ found that seed and fruit sizes were generally small throughout most of the Cretaceous, with the upward trend only beginning near the end of the period. The common belief is that plants didn’t start producing big, animal-dispersed fruits until after the asteroid impact 66 million years ago that killed off all non-avian dinosaurs and kicked off the Age of Mammals. Only then did plants have partners worth investing in. Rodents, bats, and primates diversified rapidly.

The New Mexico fossils cast serious doubt on that timeline, pushing evidence for diverse, large-fruited angiosperms back at least 10 million years prior to that extinction event.

Who was doing the eating?
The shape and size of these ancient fruits strongly suggest that animals were eating them. As these fruits became available, Cretaceous birds and dinosaurs, which are known to have eaten seeds and fruits from conifers, may have switched to angiosperms, according to the Science study. Pterosaurs and extinct rodent-like mammals, called multituberculates, are also plausible candidates. Fossilized dung from the Late Cretaceous identified in earlier research contains diaspores consistent with vertebrate ingestion.

In the Annual Review of Ecology, Evolution, and Systematics, Tiffney stated in his review ‘Vertebrate dispersal of seed plants through time’ that the Mesozoic was dominated by large herbivorous dinosaurs that could have acted as diffuse dispersal agents of whole plants, while smaller vertebrates, including early birds and mammals, may have developed more specific plant–animal associations, but the direct fossil evidence for this is scarce. The New Mexico findings now provide important weight to that possibility.

A broader evolutionary picture
The results fit other known patterns of angiosperm development in the Cretaceous, when plants were already expanding their leaves, growth forms, and overall size rapidly, University of Michigan paleobotanist Selena Smith told Science News.

The results fit with other known patterns of angiosperm development in the Cretaceous, when plants already were expanding their leaves, growth forms, and overall size rapidly, University of Michigan paleobotanist Selena Smith told Science News. “It only makes sense that the reproductive structures would be similarly evolving during the Cretaceous as plants are becoming more efficient and specialized,” she said.

Brian Atkinson, a paleobiologist at the University of Kansas who was not involved in the research, said the evidence that larger diaspore sizes were well-established before the end of the Cretaceous was “a very important finding,” and said the next step is sampling other Late Cretaceous fossil sites around the world to confirm the pattern.

These plants eventually grew into the thick, angiosperm-dominated forests we know today, but they appear to have gotten their start while T. rex was still roaming the earth.