64 of 90


What might be mistaken for dinosaur bones being unearthed at a paleontological dig in this false color satellite image are some of the individual reefs that make up the Great Barrier Reef, the world's largest tropical coral reef system. The reef stretches more than 2,000 km (1,240 mi) along the coast of Queensland and is a UNESCO World Heritage Site. It supports astoundingly complex and diverse communities of marine life and is the largest structure on the planet built by living organisms. Image courtesy of USGS.