“Exquisitely Grotesque Creature” Leaves Tracks

Feeling “bugged” this summer? Be glad youíre not living 300 million years ago when eight-foot long millipedes dominated the landscape. Now the Museum hosts evidence of the worldís largest specimen of Arthropleura. Museum scientists recovered the fossilized tracks in a remote canyon near Española. The trackway looks like two parallel rows of tire tracks.

Museum Director Adrian Hunt, PhD, was in the field with the team that recovered the rare specimen. “This is a very spectacular thing,“ he said. “Something like this has never been found before in the Western United States.“ The Arthropleura was the top of the food chain with no natural enemies for about 40 to 50 million years. It lived during the Pennsylvanian era when the Earth was covered in ferns and coal swamps 280 to 325 million years ago.

"This is basically the Tyrannosaurus of its time, millions of years before dinosaurs evolved,î explained paleontology curator Spencer Lucas. “We're not really sure what they ate. This guy probably patrolled the forest eating smaller bugs and maybe small vertebrates. New Mexico was near the equator then, and the land was much warmer and wetter.”

Today's millipedes and centipedes aren't directly related to Arthropleura but might be from a related branch of the now-extinct creature's family tree, Spencer added. “Bugs this big just couldn't survive in modern air,” Spencer said. “Insects this big, need to have a lot more oxygen. Breathing, food and locomotion are tough for a bug that big. When the world changed, they just couldn't adapt. These guys were an evolutionary dead end.”