The first beetle

The oldest known fossil beetle has been discovered not in an outcrop, but in a museum drawer. A 296 million year old insect has been reclassified as a beetle, pushing back the origin of beetles by millions of years.

The evolutionary success of beetles is traditionally explained by their two-stage life style—they pass through ecologically distinct larval and adult stages that allow them to exploit different niches.

However, the new find creates a large gap between the first appearance of beetles and the diversification of beetles that occurred 65 million years later, and suggests that the innovation of the two-stage lifestyle was not the initial cause of beetle diversity.

This opens the door to other explanations for beetle success, such as the proliferation of the plant species that was favored by the beetle larvae.

Reference: Journal of Paleontology November, 2009, The Earliest Beetle identified (Olivier Bethoux)

Photo credit: This is a much younger fossil beetle from the Eocene (15 million-year-old) Florissant Fossil Beds of Colorado, which preserves a wide variety plant and animal life. Click on today's title for more information.