Caimans are not considered “true” crocodiles, but they are members of the broader biological group that includes all crocodiles. They belong to the ancient order Crocodilia, which encompasses alligators, caimans, crocodiles, and gharials. The key distinction lies in the family classification, which separates caimans and crocodiles into two distinct groups based on physical traits and lineage. This taxonomic difference makes a caiman a crocodilian, but not a crocodile.
The Overarching Crocodilian Order
All crocodilians, including the caiman, belong to the Order Crocodilia, a group of large, semi-aquatic reptiles. This order is organized into three main families: Crocodylidae, Alligatoridae, and Gavialidae.
The Crocodylidae family is known as the “true” crocodiles and includes species like the Nile crocodile and the Saltwater crocodile. The Gavialidae family contains the gharial and the false gharial, which are characterized by their extremely long, thin snouts.
Caimans, along with alligators, are placed within the Alligatoridae family. This classification means the caiman is more closely related to an alligator than it is to a true crocodile. Caimans belong to the subfamily Caimaninae, which includes six different species.
Telling Caimans and True Crocodiles Apart
Distinguishing caimans from true crocodiles is done by observing specific details of their heads and jaws. The snout shape is the most immediate visual difference between the two families. Caimans, like their alligator relatives, possess a broad, rounded, U-shaped snout.
True crocodiles have a longer, narrower, V-shaped snout. This difference in skull structure reflects distinct hunting strategies, with the broader jaw of the caiman being suited for crushing hard-shelled prey.
Jaw alignment and tooth visibility provide another reliable method for identification. When a caiman or alligator closes its mouth, the wider upper jaw completely conceals the teeth of the lower jaw. For true crocodiles, the upper and lower jaws are nearly the same width, allowing the fourth tooth on the lower jaw to fit into an external notch on the upper jaw. This means some lower teeth remain visibly exposed along the jawline even when the mouth is closed.
Where in the World They Live
The geographic distribution and preferred habitat types offer another clear distinction. Caimans have a highly restricted range, being native exclusively to Central and South America. They are mostly found across rivers, swamps, and wetlands throughout the Amazon Basin and other tropical freshwater environments.
True crocodiles exhibit a much wider global distribution, with species found throughout tropical regions in Africa, Asia, Australia, and the Americas. Their habitats include freshwater rivers and lakes, but many species also show a greater tolerance for brackish water and marine environments.
This tolerance is linked to specialized salt glands that many true crocodiles possess, which help them excrete excess salt. Caimans lack these glands, which limits their ability to survive in saltwater for long periods.