Crocodile

Crocodile vs. alligator

The two are often confused, but they’re distinct families with different ranges and identifiable differences:

• Snout shape — crocodiles are V-shaped and pointed; alligators are U-shaped and broad.
• Visible teeth — crocodiles’ fourth lower tooth juts out when the mouth is closed; alligators’ upper jaw covers all the lower teeth.
• Habitat — crocodiles tolerate saltwater and live in tropical rivers and estuaries; alligators are freshwater specialists, mainly in the southern US and China.
• Temperament — crocodiles are generally more aggressive than alligators.

A bite without equal

The saltwater crocodile has the strongest measured bite of any living animal — around 3,700 PSI, exceeding any big cat, hyena, or shark. Crocodile jaws clamp shut with this force but open with surprisingly little — the muscles to open the mouth are weak enough that adults can be held shut by hand.

Living fossils

Modern crocodiles look strikingly similar to their 200-million-year-old ancestors. Their body plan — armored, low-slung, ambush-oriented predators with eyes and nostrils raised to the top of the head — has been so successful that natural selection has changed it relatively little since the late Triassic. They survived the asteroid impact that killed the dinosaurs.

Death roll and ambush

Crocodiles use a notorious death roll: gripping prey in their jaws and spinning their bodies rapidly to disorient and tear apart victims. Combined with explosive lunges from underwater ambush positions, this makes them lethal hunters of large mammals at riverbanks. Wildebeest crossings on the Mara River are an annual feast for Nile crocodiles waiting in the water.

Saltwater specialists

The saltwater crocodile (Crocodylus porosus) is the largest living reptile and ranges from northern Australia across Southeast Asia to eastern India. Adult males regularly exceed 6 meters; the largest verified individual was over 7 meters long. They hunt in oceans as well as rivers and have been documented swimming hundreds of kilometers across open sea.