15945 Gymnorhamphichthys hypostomus Ellis, 1912 Rhamphichthyidae Sand knifefishes Gymnotiformes Teleostei Morse Knifefish South America: upper Mamoré and Orinoco River basins. AMNH 12487 Gymnorhamphichthys hypostomus AMNH 13422 Gymnorhamphichthys hypostomus AMNH 14307 Gymnorhamphichthys hypostomus AMNH 14370 Gymnorhamphichthys hypostomus AMNH 16790 Gymnorhamphichthys hypostomus AMNH 220347 Gymnorhamphichthys hypostomus AMNH 4422 1912 Gymnorhamphichthys hypostomus AMNH 30444 1924 Gymnorhamphichthys hypostomus AMNH 9617 1929 Gymnorhamphichthys hypostomus AMNH 39762 1964 Gymnorhamphichthys hypostomus AMNH 39922 1964 Gymnorhamphichthys hypostomus AMNH 39995 1964 Gymnorhamphichthys hypostomus AMNH 40094 1964 Gymnorhamphichthys hypostomus AMNH 40113 1964 Gymnorhamphichthys hypostomus AMNH 230868 1999 Gymnorhamphichthys hypostomus AMNH 230893 1999 Gymnorhamphichthys hypostomus AMNH 230906 1999 Gymnorhamphichthys hypostomus AMNH 230912 1999 Gymnorhamphichthys hypostomus