Isalorhynchus is an extinct genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of hyperodapedontine

Hyperodapedontinae

Hyperodapedontinae is a subfamily of rhynchosaurs within the family Hyperodapedontidae. Fossils have been found from Argentina, Brasil, Canada, India, Madagascar, Scotland, Tanzania, USA and Zimbabwe.-Classification:...

 rhynchosaur

Rhynchosaur

Rhynchosaurs were a group of Triassic diapsid reptiles related to the archosaurs.-Description:Rhynchosaurs were herbivores, and at times abundant , with stocky bodies and a powerful beak...

 from the late Triassic

Triassic

The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...

 period (Carnian

Carnian

The Carnian is the lowermost stage of the Upper Triassic series . It lasted from about 228.7 till 216.5 million years ago . The Carnian is preceded by the Ladinian and is followed by the Norian...

 stage) of Toliara Province

Toliara Province

Toliara is a former province of Madagascar with an area of 161,405 km². It had a population of 2,229,550 . Its capital was Toliara...

, southwestern Madagascar

Madagascar

The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

. It is known from the holotype

Holotype

A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...

 MDE-R18, a nearly complete maxilla

Maxilla

The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper...

 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

Morondava Basin

Morondava Basin is one of the major sedimentary basins of Madagascar. It encompasses the large Tsimiroro heavy oil field and giant Bemolanga ultra heavy oil field....

 (or Isalo beds). It was first named by Eric Buffetaut in 1983

1983 in paleontology

-Newly named dinosaurs:Data courtesy of George Olshevsky's dinosaur genera list and Dr. Jeremy Montague's dinosaur genus database.-New taxa:-Non-mammalian:...

 and the type species

Type species

In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the 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

Hyperodepedon

Hyperodapedon is a genus of rhynchosaur from the late Triassic period . The type species of Scaphonyx , Scaphonyx fischeri that once thought to be a dinosaur, is now known to be based on dubious material and therefore should be a nomen dubium...

and referred it to a new species of Hyperodepedon. Whatley, 2005 retained this genus as valid with a description of new materials in her PhD thesis. Montefeltro et al., 2010 and Langer et al., 2010 accepted Isalorhynchus as valid genus.