''Isalorhynchus'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of hyperodapedontine

rhynchosaur Rhynchosaurs are a group of extinct herbivorous Triassic archosauromorph reptiles, belonging to the order Rhynchosauria. Members of the group are distinguished by their triangular skulls and elongated, beak like premaxillary bones. Rhynchosaurs ...

from the late

Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...

period Period may refer to: Common uses * Period (punctuation) * Era, a length or span of time *Menstruation, commonly referred to as a "period" Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (o ...

(

Carnian The Carnian (less commonly, Karnian) is the lowermost stage (stratigraphy), stage of the Upper Triassic series (stratigraphy), Series (or earliest age (geology), age of the Late Triassic Epoch (reference date), Epoch). It lasted from 237 to 227.3 ...

stage) of

Toliara Province The Toliara Province (formerly Toliary or Tuléar) is a former province of Madagascar with an area of . It had a population of 2,229,550 (July, 2001). Its capital was Toliara. Near Toliara was the " spiny forest". Toliara Province bordered the foll ...

, southwestern

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

. It is known from the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

MDE-R18, a nearly complete

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

and from other specimens from the same locality, Malio River area. It was found in the

Makay Formation Isalo II, also known as the Makay Formation, is an informal Triassic geological unit in Madagascar. It is described as "thick beds of mottled red or green clays associated with soft cross-bedded sandstones, light in colour and much finer-grained ...

(or Isalo II) of the

Morondava Basin Morondava Basin is one of the major sedimentary basins of Madagascar. It encompasses the large Tsimiroro heavy oil field Field may refer to: Expanses of open ground * Field (agriculture), an area of land used for agricultural purposes * Airfi ...

(or Isalo beds). It was first named by

Eric Buffetaut The given name Eric, Erich, Erikk, Erik, Erick, Eirik, or Eiríkur is derived from the Old Norse name ''Eiríkr'' (or ''Eríkr'' in Old East Norse due to monophthongization). The first element, ''ei-'' may be derived from the older Proto-Nor ...

1983 1983 saw both the official beginning of the Internet and the first mobile cellular telephone call. Events January * January 1 – The migration of the ARPANET to TCP/IP is officially completed (this is considered to be the beginning of the ...

and the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

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 ''

Hyperodapedon ''Hyperodapedon'' (from , 'above' and , 'pavement') is an extinct genus of rhynchosaur reptiles which lived during Triassic, Late Triassic period. Like other rhynchosaurs, it was an heavily built Archosauromorpha, archosauromorph, distantly rel ...

'' and referred it to a new species of ''Hyperodapedon''. 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.

Phylogeny

''Isalorhynchus'' in a

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

based on Ezcurra ''et al.'' (2016):

References

Rhynchosauria Late Triassic reptiles of Africa Triassic Madagascar Fossil taxa described in 1983 Taxa named by Éric Buffetaut Prehistoric reptile genera {{triassic-reptile-stub