''Notoceratops'' (meaning "southern horned face") is a dubious

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 ...

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 ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

. The genus was described based on an incomplete, toothless left

dentary In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone ...

(now lost) from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

Patagonia Patagonia () is a geographical region that includes parts of Argentina and Chile at the southern end of South America. The region includes the southern section of the Andes mountain chain with lakes, fjords, temperate rainforests, and glaciers ...

(in

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

), probably dating to the

Campanian The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

. Initially classified as a putative

ceratopsia Ceratopsia or Ceratopia ( or ; Ancient Greek, Greek: "horned faces") is a group of herbivore, herbivorous, beaked dinosaurs that thrived in what are now North America, Asia and Europe, during the Cretaceous Period (geology), Period, although ance ...

n found in the Lago Colhué Huapi Formation, the lost fragmentary holotype precludes confident referral of this taxon within ornithischians, with some researchers suggesting that it belongs to a

hadrosaur Hadrosaurids (), also hadrosaurs or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod fami ...

instead.

Discovery and naming

In 1918,

palaeontologist Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geolo ...

Augusto Tapia (1893–1966) discovered the genus

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 ...

. He also named 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 ...

, ''N. bonarellii'' (originally spelt as ''Notoceratops Bonarelli''), in 1918. The generic name is derived from Greek ''notos'', "the south", ''keras'', "horn" and ''ops'', "face". The specific name honours Guido Bonarelli (1871-1951), who advised Tapia in his study of the find. By present conventions the epithet is spelled ''bonarellii'', thus without a capital B. In many later publications the specific name is misspelled "bonarelli", with a single "i", from the incorrect assumption it would be derived from a Latinised "Bonarell~ius". The fossil, found near the Lago Colhué Huapi in Chubut, was eventually described by Friedrich von Huene in 1929, but it has since been lost.

Phylogeny

Originally referred as a

ceratopsian Ceratopsia or Ceratopia ( or ; Greek: "horned faces") is a group of herbivorous, beaked dinosaurs that thrived in what are now North America, Asia and Europe, during the Cretaceous Period, although ancestral forms lived earlier, in the Late Ju ...

by Tapia in 1918, it was later dismissed because no other members of that group were known from the Southern Hemisphere. However, the 2003 discovery of another possible ceratopsian, '' Serendipaceratops'', from Australia could change this view. ''Notoceratops'' has since been considered a ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium,'' it may be impossible to determine whether a ...

'' and may have been a

instead. An analysis published by Tom Rich et al. (2014), which focused on the validity of ''Serendipaceratops'', also examined the published material from ''Notoceratops'' and concluded that the holotype had ceratopsian features.

References

{{Taxonbar, from=Q141611 Ornithischia Dinosaur genera Campanian dinosaurs Fossil taxa described in 1918 Dinosaurs of Argentina Taxa with lost type specimens