Chelus fimbriata, the matamata turtle (Family Chelidae), is the largest member of its pleurodiran family, and is surely the most bizarre turtle in the world. It has an exceedingly rough, tuberculate carapace, a greatly elongated and thickened neck, and a wide, triangular, extremely flattened head, with a tubular nasal extension, reduced anteriorly displaced eyes, and an extremely wide mouth. It is specialized for feeding upon live fish that it sweeps into its mouth by a rapid lateral strike of the neck and jaws, and a vigorous simultaneous expansion of the hyoid apparatus in the neck. It is distributed widely in South America, and currently does not appear to be threatened significantly anywhere in its range.

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