Newly discovered 52-million-year-old fossil hints one fruit is a lot older than we thought

Turns out old things come in small packages. Tomatillos are fruits that look like small green tomatoes with delicate husks on them, and they might be a whole lot older than scientists previously thought. 

According to a new paper published in Science, researchers found a fossil of a variety of an ancient tomatillo that dates back 52 million years ago. Experts previously believed the tomatillo and other nightshade plants, like potatoes and eggplants, first evolved 40 million years ago, Richard Olmstead, an evolutionary biologist at the University of Washington told NPR. 

A team of researchers found the fossil, an imprint of the tomatillo's husk that was about the size of a paperclip, in a former lake bed in Patagonia, Argentina, NPR reported. 

"Each new fossil helps us better reconstruct the past, and understanding history of all kinds is the key to navigating the present and near future,"  Peter Wilf, a paleobotanist at Penn State University and the lead author of a new paper, said in an email. 

This is also a big freakin' deal because tomatillos are thought to be more evolved than other nightshades, meaning the ancestors of the tomatillo might just possibly have been around when dinosaurs walked the earth, Wilf explained to NPR. 

Tomatillos are older than humans, that's for sure, but it's possible our ancestors chowed down on early iterations of tomatillo and other nightshades. Scientists discovered fossils of Neanderthal poop in southern Spain and deduced that people were eating a meat-heavy diet but also ingesting some plants, National Geographic reported, explaining pollen samples from the region reveal the Neanderthals could have eaten early potatoes, which are in the same nightshade family as tomatillos.

"That fossil is a message from the past, from a time before wifi, before roads, before politics, well before any people at all, when the climate and other conditions of life were totally different from today." - Peter Wilf, paleobotanist

The ancient tomatillo has been through a lot, Wilf explained. "After the time of these fossils, South America separated from Antarctica, which began its glaciation, and global temperatures began their slow decline toward today's icehouse conditions," he noted, explaining that the land know known as Patagonia became colder and drier and new species lineages evolved to adapt to the new conditions. Since the Andes uplift began 15 million years ago, the tomatillo and nightshade family have adapted to occupy a large range of habitats. 

"That moment when you look at a new fossil that no one else has ever seen.. is life-changing," Wilf said when asked about the thrill of discovering new fossils. He said sometimes researchers yell or cry when a lucky blow of a hammer allows them to discover their first fossil. "That fossil is a message from the past, from a time before wifi, before roads, before politics, well before any people at all, when the climate and other conditions of life were totally different from today."

The discovery of ancient tomatillo is an inspiring tale when you think about it. If the ancient fruit (yes, it's a fruit!) survived — heck, thrived — over 50 million years on planet Earth, you can survive whatever the week throws your way.