the.com/stromatolites
rocks that were once alive, layered by bacteria too patient to evolve a spine.
means layered mineral structures built by microbial mats trapping sediment, one thin film at a time, for millennia.
from from greek stroma (bed, layer) plus lithos (stone) — coined in 1908 to describe fossil rock beds that turned out to be ancient life caught mid-build.
age recordsome date back 3.5 billion years
oxygen debtthey helped fill earth's atmosphere with oxygen
growth ratecan take a century to add one centimeter
near extinctiongrazing animals nearly wiped them out later
for instance
shark bay australia — living colonies since the 1950s, unesco site
lake thetis — western australia's smaller, accessible stromatolite lake
pilbara formations — western australia rocks holding earth's oldest fossil evidence
bahamas exuma cays — rare living marine stromatolites still forming today