Hairy Museum of Natural History

A Paleozoic moon rises, hanging full and swollen on the horizon. Three hundred-million years ago the moon is closer, and its pull is stronger. At some distant ocean’s shore the tides rise high and horsehoe crabs clamber up onto the beach to spawn, drawn by the moon into a dance that they will continue, year after year, to the present day.

Farther inland, the moon climbs above a tropical forest of tree-sized horsetails and a different dance commences. Antennae probe the thick, humid air and the moonlight glints across multi-faceted eyes. Rivers of roughened cuticle eight feet long flow up from the frond litter and across the forest floor, and the air is filled with rustling as they snake around the gritty trunks of the horsetail jungle.

One by one, giant centipede-like forms emerge from the forest along the edge of an ancient lake. Their pace slows as they crawl across the lakeshore mud, but their stride never falters. Dozens of stout, spiny legs undulate in absolute precision, propelling the animals across the beach towards moonlit rendezvous. Their dance, unlike that of the horseshoe crabs, will falter after a few million years. The world will change, and their unparalleled invertebrate stature will prove impossible to maintain.

Year after year, the number of Arthropleura on the beach will diminish. None will remain at the close of the Carboniferous, but in certain places, the footsteps of their dance will be preserved.

—Matt Celeskey.

File under: Carboniferous, Permian.