Marine Iguanas on Lava Shore

Marine Iguanas on Lava Shore is an original illustration set in Fernandina Island, Galapagos, Ecuador. It lies in equatorial latitudes, where the climate is hot desert — evaporation far outruns rainfall.

Several charcoal-black iguanas lie warming on ropy black basalt at a dry shoreline. The largest, in the foreground, shows a blunt snout, a spiny dorsal crest and a salt-crusted crown. Two others angle toward white surf. Sparse prickly pear and pale dry scrub stand behind, with a low shield volcano far across the water.

Why does this iguana have a crust of salt on its head?

The salt crust is the giveaway: this lizard feeds underwater on algae and sneezes concentrated brine out through a gland above its nose. Nowhere else has a marine lizard evolved. Ropy black basalt and a low shield-shaped volcano mean fluid lava from a hot spot, not an explosive arc, and a desert-dry shore directly on the equator points to a cold current running past.

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