Ololygon argyreornatus, commonly known as the Rio Mutum snouted treefrog, is a species of frog in the family Hylidae endemic to Brazil. Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical moist montane forests, subtropical or tropical moist shrubland, freshwater marshes, intermittent freshwater marshes, and heavily degraded former forests. It is threatened by habitat loss. References argyreornatus Endemic fauna of Brazil Amphibians of Brazil Amphibians described in 1926 Taxa named by Alípio de Miranda-Ribeiro Taxonomy articles created by Polbot Taxobox binomials not recognized by IUCN