Ancient microbe fossils show earliest evidence of shell making
809-million-year-old eukaryotes turned calcium phosphate into armor
SHELL GAME Roughly 809-million-year-old microbe fossils, such as this one found in Canada, may be the oldest evidence of organisms creating minerals for protection against predators. The shells take many shapes, including this honeycomb pattern.
P. Cohen
DENVER — Life on Earth got into the shell game more than 200 million years earlier than previously thought.
Fossilized eukaryotes — complex life-forms that include animals and plants — discovered in Canada are decked out in armorlike layers of mineral plates, paleobiologist Phoebe Cohen said September 27 at the Geological Society of America’s annual meeting. At about 809 million years old, the find is the oldest evidence of organisms controlling the formation of minerals, a process called biomineralization.
This new origin of biomineralization coincides with major changes that mark the end of a period known as the “boring billion” (SN: 11/14/15, p. 18), said Stanford University paleontologist Erik Sperling, who was not involved in the discovery. “There were big things going on with ocean chemistry,” he said.
