What the species is and where it came from
The marine iguana (Amblyrhynchus cristatus) is a reptile found only on the Galápagos Islands. It was first described in 1825. It is endemic, taxonomically distinct, and ecologically specialized.
How it works, in terms someone would actually use
It forages in the sea for algae. Large males dive. Females and smaller males feed in the intertidal zone at low tide. It basks on rocky shores after cold-water foraging. It nests in soil on land, laying eggs that hatch unattended after several months.
What it gets right
It gets marine foraging right. It gets thermoregulation via basking right. It gets nesting simplicity right—no parental care, just soil, sun, and time.
What it does not
It does not regulate its body temperature efficiently in cold water. It does not avoid predators introduced by humans. It does not survive El Niño-driven algae collapse without population loss.
What it changed
It changed how we define lizard ecology. No other living lizard occupies the marine foraging niche. Its existence proves marine adaptation is possible in squamates.
Who it is for, and who it is not
It is for observers on Galápagos rocky shores, intertidal zones, mangrove swamps, and beaches. It is not for inland forests, coral reefs, or anywhere outside the archipelago.
Is it worth your time
Yes—if you are on the Galápagos Islands and want to see a reptile doing something no other lizard does: swimming and feeding underwater.
