The Mexican share of the oldest fossils on Earth

The first reefs of stromatolites date back some 3.5 billion years! They are structures formed by microorganisms like cyanobacteria or microbial mats. They were widespread on Earth abut Mexico has its share of living stromatolites located in the Laguna Bacalar, Quintana Roo. They are fragile ecosystems because … more @ThePlayaTimes here.