The mata mata ('Chelus fimbriata') is a freshwater turtle found in South America, primarily in the Amazon and Orinoco basins. It is the only extant species in the genus 'Chelus'.

It is a large, sedentary turtle with a large, triangular, flattened head with many tubercles and flaps of skin, and a "horn" on its long and tubular snout. Three barbels occur on the chin and four additional filamentous barbels at the upper jaw, which is neither hooked nor notched.

Mata mata turtles use a specific method of seizing their prey. They will move the prey into shallower areas of water, surround the prey, and wave their front legs to prevent them from escaping. Once surrounded, the mata mata turtles will open their mouths and contract their pharynx, causing a rush of water that pushes the prey into their mouth.

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