There are 23 species in the group Crocodilia, including crocodiles, alligators, caimans, and gharials. Members of this group have occupied the earth for more than 200 million years, they have been important members of ecosystems since the age of the dinosaurs! All crocodilians are adapted to a semi-aquatic lifestyle and are important predators. All crocodilians have similar body shapes, with long tails, heavily armored bodies, long heads with large mouths full of conical teeth, and eyes set near the tops of their heads to allow for binocular vision. Crocodilians range in size from smaller caimains, which reach a maximum of 1.5 meters in length (5 feet) to large crocodiles, which have been recorded up to 7 meters long (23 feet). Crocodilians occur throughout the world in tropical and semi-tropical areas.