Rare Leafcutter Bee Fossil Provides Insight to Environmental Ice Age Conditions

Scientists have recently had the rare opportunity of studying leafcutter bee fossils, providing an insight to the environment of the Ice Age.

According to LiveScience, the scientists found the fossils in the Rancho La Brea Tar Pits in Los Angeles, Calif., known to be the world's richest source of Ice Age artifacts. Researchers have previously found remnants of saber tooth cats and mammoths at the tar pits.

With high-resolution micro-computed tomography (CT), scientists examined the fossilized leafcutter bee nests for clues to the environmental conditions of the Ice Age. In a study published in the journal PLOS One, the researchers determined the nests belonged to a bee species alive today, known as Megachile gentilis.

"Based on what we know about them today and the identification of fossilized leaf fragments, we know that their habitat at the Tar Pits was at a much lower elevation during the Ice Age," study lead author Anna Holden, an entomologist at the Natural History Museum of Los Angeles County, told LiveScience.

Leafcutter bees are solitary and do not have colonies like honeybees. Female leafcutters build small cylindrical nests "look like mini cigars" out of leafs and flower petals.

"I had read some of the big literature that said leafcutter bees aren't really identifiable by their nest cells," Holden said. "But I thought, 'That just can't be true; there's got to be a way.'"

Using data and knowledge on the environmental and climate conditions necessary for survival, the researchers were able to dig up information on the Ice Age. The study authors believe the bees placed their nests in the tar pit intentionally because they were not likely to migrate due to climate change. The team concluded these leafcutters lived in a low-altitude area in the Late Pleistocene period with a moist climate.

"Because this is a fossil of rare life-stage, it's an exceptional find in itself," Holden said in a press release. "But it's just the tip of the iceberg, we know that insects offer a vivid portrait of the prehistoric conditions of this area, and there are literally thousands more to study."