Fossilized Bee Nests Inside Skeletons Are Unlike Anything We’ve Seen Before

Scientists studying an island cave in the Caribbean Sea have discovered something unexpected: ancient bees are very different from the hive-dwelling insects we are so familiar with.

For the first time ever, paleontologists have discovered fossil traces of bees hiding inside the buried bones of other animals. These fossils, thousands of years old, are the end result of a horrific life cycle that included ancient rodents and giant barn owls. They may also teach us some lessons about bees today, researchers say.

“I think the most important finding is to show how diverse bee nesting behavior is,” study researcher Lazaro Viñola Lopez told Gizmodo.

An “accidental” discovery.

Viñola Lopez was working as a doctoral student at the Florida Museum of Natural History when she helped excavate fossils from inside the cave on the island of Hispaniola (the cave is located on the eastern half of the island, which is owned by the Dominican Republic). But neither he nor his colleagues were planning to make such a discovery.

“This discovery was very serendipitous. We were looking for primates, rodents, lizards and other vertebrates for our work on late Quaternary extinctions on islands associated with humans and climate changes,” he said. “We weren’t looking for any insects because they don’t usually exist in this type of environment.”

The cave, called Cueva de Mono, contains thousands of fossils belonging to the hutia, a rodent related to the guinea pig. This discovery was surprising enough, given how rare Hutia fossils are in the area. But Vignola Lopez also noticed that one of the fossils, a specimen of a lower jaw from Hutia, had unusual softness.

Vignola Lopez didn’t immediately delve into his potential discovery, and there were some bumps along the way. Based on his previous work with dinosaur fossils, he initially speculated that the remains of the hutia were used by wasps to build their nests, but the features of these nests did not exactly match what he found.

However, he eventually realized that these remains were most likely used by a different insect, an ancient species of burrowing bee. usnidom almonte, That lived thousands of years ago. Thanks to subsequent excursions into the cave to recover more fossils, they also found evidence of these nests within the hutia vertebra and the pulp cavity of sloth teeth (sloths once lived on the Caribbean islands, but have been largely wiped out by human activity).

The team’s findings were published on Tuesday in the Proceedings of the Royal Society B for Biological Sciences.

Unusual bees

Although we mostly think of bees as social insects that build elaborate nests in plain sight, Vignola Lopez points out that most bee species live in isolation and use a wide range of structures and materials for nesting. But while these ancient bees seem to share a lot in common with their modern counterparts, they are also distinct in important and mysterious ways.

He said: “The bees that created these monuments are similar to other bees in that they nest in the ground, but they differ from all other known species in that they regularly use chambers in buried bones (such as tooth cavities).” Another major difference is the cave placement of these fossils. There has only been one other documented case of burrowing bees using a cave for their nests, according to the researchers, and that did not involve the bees using another animal’s fossil remains.

As best they could tell, the cave was home to a group of ancient barn owls that also regularly used it as a dumping ground for the hutia they hunted. The owls may have taken the rodents home for dinner or sometimes taken them out of the meal on the go. These remains later proved to be an attractive nesting site for bees. Although most of the surrounding area is unsuitable for these insects, the cave and other similar sites may have contained enough built-up soil for bees to rely on for nests.

Aside from learning more about bees, the team’s research has also taught them to be more careful.

“It has changed the way we look at and prepare fossils from cave deposits in the Dominican Republic. Now we pay more attention before cleaning them to make sure we don’t destroy any other interesting behavior of ancient insects hiding in the sediments inside the fossils,” he said.

Ancient cave bees aren’t the only discovery researchers hope to make. They are already working to describe many other fossils recovered from the cave, which should include never-before-seen species of mammals, reptiles and birds.