April 24, 2025

16-Million-Year-Old Ant Preserved in Amber Shines Light on Evolutionary History

In the world of gemology, few treasures rival the rarity and allure of a flawless diamond. But for entomologist Gianpiero Fiorentino, an equally thrilling find came not from the depths of the Earth, but encased in ancient fossilized tree resin: a 16-million-year-old “dirt ant” preserved in pristine Dominican amber.

“Dirt ants are rare finds in the wild,” says Fiorentino, a Ph.D. candidate at NJIT. “But captured in amber, it’s like finding a diamond.”

Discovered in the Dominican Republic, the fossil — Basiceros enana — represents the first-ever Caribbean specimen of this cryptic ant genus. Known for their camouflage skills, modern dirt ants use specialized hairs to coat themselves in soil and leaf litter, blending seamlessly into their environment.

Their elusive nature makes them difficult to study, which only amplifies the value of this amber-encased fossil. It provides an unobstructed window into a long-extinct species, once native to Caribbean soil during the Miocene epoch (23 million to 5.3 million years ago).

The preservation of such intricate biological detail is a testament to amber’s unique properties. Formed from hardened tree resin, amber can preserve organisms in near-perfect three-dimensional fidelity, down to microscopic features.

This theme famously captured the public imagination in the 1993 blockbuster Jurassic Park, where dinosaur DNA was extracted from blood-engorged mosquitoes trapped in amber. While the science of cloning dinosaurs remains fictional, amber’s role as a natural time capsule is very real — and incredibly valuable to researchers.

Using micro-CT scanning and 3D reconstruction, Fiorentino and his team examined the fossil in extraordinary detail, revealing that Basiceros enana is significantly smaller than its modern relatives.

This discovery flips previous assumptions on their evolutionary trajectory; instead of shrinking over time, dirt ants appear to have doubled in size over the past 16 million years.

Even more astonishing, Basiceros enana already had many of the modern traits of its lineage — adaptations such as dirt-trapping hairs and sharply toothed mandibles — suggesting that its camouflage strategies were in place millions of years ago. The team’s findings were recently published in the Proceedings of the Royal Society B.

Amber has been cherished by humans for a very long time, with evidence of its use as an adornment and in trade as early as 13,000 years ago.

The ancient Greeks believed amber was born from tragedy: the petrified tears of the Heliades, who mourned their brother Phaëton after his doomed ride in the sun chariot. Their grief, immortalized in glowing drops of fossilized resin, underscores amber’s enduring association with divine power and elite status.

Today, more than 90% of the world’s amber comes from Kaliningrad, a Russian territory along the Baltic Sea. This region continues to produce large quantities of Baltic amber, prized in jewelry for its warm tones and inclusions — sometimes containing insects, just like the one that cradled Basiceros enana for millions of years.

This stunning discovery is more than an evolutionary footnote — it’s a golden intersection of geology, biology, mythology and fine jewelry. Like the finest gemstone, this tiny ant trapped in time reminds us that nature’s most exquisite creations often come in the smallest, most unexpected packages.

Credits: Photomicrograph of a newly discovered extinct dirt ant species preserved in Dominican amber courtesy of Gianpiero Fiorentino (NJIT). Artistic rendition of Basiceros enana preserved in Dominican amber from CT-scan data courtesy of Gianpiero Fiorentino (NJIT). Tumble-polished Baltic amber photo by W.carter, CC BY-SA 4.0, via Wikimedia Commons.