The fossilized trail of an aquatic creature suggests that animals walked using legs at least 30 million years earlier than had been thought. The tracks -- two parallel rows of small dots, each about 2 millimeters in diameter -- date back some 570 million years, to the Ediacaran period.
© Kevin Fitzsimons, Ohio State University
Trackway of one of the earliest animals, a multi-legged creature that walked over the bed of an ancient sea once covering Nevada. The animal left behind a pair of parallel impressions - small, round dots in the silt that later became rock.
The Ediacaran preceded the Cambrian period, the time when most major groups of animals first evolved.
Scientists once thought that it was primarily microbes and simple multicellular animals that existed prior to the Cambrian, but that notion is changing, explained Loren Babcock, professor of earth sciences at Ohio State University.
"We keep talking about the possibility of more complex animals in the Ediacaran -- soft corals, some arthropods, and flatworms -- but the evidence has not been totally convincing," he said. "But if you find evidence, like we did, of an animal with legs -- an animal walking around -- then that makes the possibility much more likely."
Comment: Interesting that the power structures of society have nearly destroyed an analogous ability within the human population to recognize pychopathic predators and share that knowledge, particularly in women.