Scientists at the University of California, Riverside have discovered a fossil of a newly discovered organism from the “Ediacara Biota”—a group of organisms that occurred in the Ediacaran period of geologic time.
Named Plexus ricei and resembling a curving tube, the organism resided on the Ediacaran seafloor. Plexus ricei individuals ranged in size from 5 to 80 centimeters long and 5 to 20 millimeters wide. Along with the rest of the Ediacara Biota, it evolved around 575 million years ago and disappeared from the fossil record around 540 million years ago, just around the time the Cambrian Explosion of evolutionary history was getting under way.
“Plexus was unlike any other fossil that we know from the Precambrian,” said Mary L. Droser, a professor of paleontology, whose lab led the research. “It was bilaterally symmetrical at a time when bilaterians—all animals other than corals and sponges—were just appearing on this planet. It appears to have been very long and flat, much like a tapeworm or modern flatworm.” Via Paleontologists discover new fossil organism.