Isalorhynchus is an extinct genus of hyperodapedontine rhynchosaur from the late Triassic period (Carnian stage) of Toliara Province, southwestern Madagascar. It is known from the holotype MDE-R18, a nearly complete maxilla and from other specimens from the same locality, Malio River area. It was found in the Makay Formation (or Isalo II) of the Morondava Basin (or Isalo beds). It was first named by Eric Buffetaut in 1983 and the type species is Isalorhynchus genovefae. The majority of Isalorhynchus specimens are isolated jaw bones, but two nearly complete skeletons were found in 1998. Langer et al., 2000 concluded that Isalorhynchus is a synonym of Hyperodepedon and referred it to a new species of Hyperodepedon. Whatley, 2005 retained this genus as valid with a description of new material