Description: The great Permian extinction, which took place about 251 million years ago, destroyed as much as 90 percent of all marine species and a lot of land-bound life as well. This post-extinction scene—a tropical coastline much like the modern southern Persian Gulf coast—is home to slimy mounds known as stromatolites. Formed by an unlikely partnership of photosynthetic bacteria and algae, these stinky, slimy mounds inhabit shallow and salty pools.

Formation: Lykins

Artist: Jan Vriesen

Best Viewing Spots: Roxborough State Park Garden of the Gods Park and Visitor Center Red Rocks Park and Amphitheatre

Roxborough State Park contains examples of the Lykins Formation that was mined to make the mortar that binds bricks in Denver's Larimer Square buildings.

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