Marine iguanas

The Galapagos are baby islands, fresh from underwater volcanic action, some less than 500,000 years old.  So, while they're working at it, they aren't terribly fertile, and many look like hardened volcanic ash, which they are.  Marine iguanas have adapted.

The only marine lizard, these evolved from land iguanas to feed on what was available and plentiful -- coastal seaweed. Their noses flattened, their tails became vertical for swimming (like a gator), and they developed salt-eliminating glands.  They can stay underwater for over an hour, grazing. The water's cold and when they come out they need to quickly warm their bodies for digestion, and to get ready to do it again.  And while the volcanic rocks are warm, they pile onto each other for added warmth in the cooler months.  

Marine iguana, feeding underwater. 

Looking out to sea.

Hanging out - they're sociable creatures.

A warming pile of friends. 

They expel excess seasalt through special nasal glands.  It's explosive and surprising, and they always look a little drippy, like they need a tissue afterwards.  I've seen only a few people who have mastered this nasal snort.

In a warm spot of sand - no need to move out of the path just for us.

They're harmless, have few natural predators as adults, and, being Galapagos inhabitants, are unconcerned about humans.

The multitudes.  The roughness apparent on the rocks is hundreds of iguanas, warming in the sun.

They grow to about a meter in length.

Another great place to hangout with friends.  Notice the tail tracks.

Tail up - means it's pooping, otherwise it's tail down, hence the tracks as above.

And a land iguana, the marine's ancestor.  Notice its tail, lost in some epic battle for survival.