(Genus) (Species) The South American lungfish (Lepidosiren paradoxa), also known as the American mud-fish[6] and scaly salamanderfish,[7] is the single species of lungfish found in swamps and slow-moving waters of the Amazon, Paraguay, and lower Paraná River basins in South America.

[14] Juvenile lungfish feed on insect larvae and snails, while adults are omnivorous, adding algae and shrimp to their diets, crushing them with their heavily mineralized tooth-plates.

The fish's usual habitats disappear during the dry season, so they burrow into the mud and make a chamber about 30–50 cm (12–20 in) down, leaving a few holes to the surface for air.

[12] Fossils of the modern species have been found between 72 and 66 mya during the Maastrichtian stage of the late Cretaceous just before the KPG extinction that killed off the non-avian dinosaurs.

[19][20][21] PiRNA, a type of RNA that normally suppresses transposon activity, was found in low levels in the animal and is possibly among the causes of such a large genome.