''Yamaceratops'' is a

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 primitive

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 ...

that lived in

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

during 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 ...

period in what is now the Javkhlant Formation. Initially, the rocks where it was found in were thought to be from the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

, but the age was reevaluated in 2009. It was a relatively small dinosaur, reaching in length and in body mass. 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 ...

, ''Yamaceratops dorngobiensis'', was described by P. J. Makovicky and M. A. Norell in September, 2006. The authors consider the animal to have had an intermediate phylogenetic position between ''

Liaoceratops ''Liaoceratops'', meaning "Liaoning horned face", is a ceratopsian dinosaur believed to be an early relative of the horned ceratopsids. It lived in the Early Cretaceous, 126 million years ago. It was discovered in China by a team of American and ...

'' and ''

Archaeoceratops ''Archaeoceratops'', meaning "ancient horned face", is a genus of basal neoceratopsian dinosaur from the Early Cretaceous (Aptian stage) of north central China. It appears to have been bipedal and quite small, reaching in length and in body m ...

'' within

Neoceratopsia 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 ...

. Examination of the frill of ''Yamaceratops'' has convinced the authors that the frill was not used for display, and that the fossils "hint at a more complex evolutionary history for ceratopsian frills". Furthermore, ''Yamaceratops'' has been dated to either

Aptian The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), S ...

-early

Albian The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...

, to even as early as mid-

Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 125.77 Ma (million years ago) and 121.4 ± 1.0 Ma (Historically, this stage was placed at 129.4 million to approximately 125 million years ago) It is a ...

. This likely predated ''Archaeoceratops'' and ''

Helioceratops ''Helioceratops'' is a genus of herbivorous neoceratopsian dinosaur from the Middle Cretaceous of China. Discovery and naming In 2000 and 2002, at the Liufangzi site of China's eastern Jilin province, excavations took place during which the j ...

'', but not ''Liaoceratops''. While there are many similarities between all four specimens, placing any into a specific family can be extremely difficult, and hotly contested between research teams. The genus name refers to

Yama Yama (), also known as Kāla and Dharmarāja, is the Hindu god of death and justice, responsible for the dispensation of law and punishment of sinners in his abode, Naraka. He is often identified with Dharmadeva, the personification of ''Dharm ...

, a

Tibet Tibet (; ''Böd''; ), or Greater Tibet, is a region in the western part of East Asia, covering much of the Tibetan Plateau and spanning about . It is the homeland of the Tibetan people. Also resident on the plateau are other ethnic groups s ...

Buddhist Buddhism, also known as Buddhadharma and Dharmavinaya, is an Indian religion and List of philosophies, philosophical tradition based on Pre-sectarian Buddhism, teachings attributed to the Buddha, a wandering teacher who lived in the 6th or ...

deity; the species name to the Eastern

Gobi The Gobi Desert (, , ; ) is a large, cold desert and grassland region in North China and southern Mongolia. It is the sixth-largest desert in the world. The name of the desert comes from the Mongolian word ''gobi'', used to refer to all of th ...

. 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 ...

IGM 100/1315 consists of a partial skull; other material has been found in 2002 and 2003 and has been ascribed to the genus. A fossilized embryo found within an ornithischian eggshell from sediments where ''Yamaceratops'' is common, was in 2008 referred to this genus. However, in 2015 it was reidentified as a bird embryo. In 2020 Minyoung Son and colleagues reported a juvenile specimen of ''Yamaceratops'' found in 2014 at the Khugenetjavkhlant ("Khugenslavkhant") locality. This probably three years old specimen, MPC-D 100/553, was described in detail in 2022.

References

External links

Dinosaur Mailing List announcement of the description (contains full abstract of the paper)

Description and Image (in German)
{{Taxonbar, from=Q132517 Ceratopsia Dinosaur genera Santonian dinosaurs Dinosaurs of Mongolia Fossil taxa described in 2006 Taxa named by Mark Norell

See also

References

External links