Tracks found in Scotland look to be from an ancient water scorpion as big as a kitchen table. If the analysis is right, it is the first evidence of the creature coming ashore.
The scorpion, a six-legged thing called Hibbertopterus, was about 5 feet long and 3 feet wide. It is long since extinct.
Researchers already knew Hibbertopterus existed from fossils, but they've debated whether it ever came on land.
The tracks, found by Martin Whyte of the University of Sheffield, cover nearly 20 feet of ground. They reveal a lumbering, jerky motion, Whyte explains in the Dec. 1 issue of the journal Nature.