High Quality Content by WIKIPEDIA articles! Lundomys molitor, also known as Lund`s Amphibious Rat or the Greater Marsh Rat, is a semiaquatic rat species from southeastern South America. Its distribution is now restricted to Uruguay and nearby Rio Grande do Sul, Brazil, but it previously ranged east into Minas Gerais, Brazil, and west into eastern Argentina. The Argentinean form may have been distinct from the living form from Brazil and Uruguay. L. molitor is a large rodent, with the head and body length averaging 193 mm (7.60 in), characterized by a long tail, large hindfeet, and long and dense fur. It builds nests above the water, supported by reeds, and it is not currently threatened.