“They got stuck in asphalt, stuck like flies on fly paper. If they were lucky, they succumbed to hunger and thirst after about a week. If they were unlucky, they were torn apart by wandering predators and scavengers.”

In the past, paleontologists focused on the large mammals, but the remains of smaller creatures such as snails or insects are now getting more attention. These microfossils give scientists a better picture of the ancient ecosystem. They also tell scientists how organisms are affected by climate change.

Unlike the extinct large mammals, the descendants of these smaller creatures still exist but do not necessarily live in the same area as their ancestors.

“Well if we have some idea of how life changes when we have changes in climate, then we can take precautions when we’re actually undergoing those same climatic changes ourselves,” said Harris.

Scientists say the plants and animals preserved in tar can tell them how global warming in the past affected ancient organisms and can help them understand which species may be the most vulnerable as temperatures rise in the modern world.