''Helioceratops'' 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 herbivorous
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 ...
n
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 ...
from the
Middle Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 77.1 million years, it is the ninth and longest geologi ...
of
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...
.
Discovery and naming
In 2000 and 2002, at the Liufangzi site of China's eastern
Jilin
)
, image_skyline = Changbaishan Tianchi from western rim.jpg
, image_alt =
, image_caption = View of Heaven Lake
, image_map = Jilin in China (+all claims hatched).svg
, mapsize = 275px
, map_al ...
province, excavations took place during which the jaws were found of a ceratopsian new to science.
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 ...
''Helioceratops brachygnathus'' was named and described in 2009 by Jin Liyong, Chen Jun, Zan Shuqin and
Pascal Godefroit. The generic name means "sun horned face" from the Greek ''helios'', "sun", ''keras'', "horn" and ''ops'', "face". The reference is that the Sun rises in the East and ceratopsians also "rose" in the East; i.e. they originated in the
Orient
The Orient is a term referring to the East in relation to Europe, traditionally comprising anything belonging to the Eastern world. It is the antonym of the term ''Occident'', which refers to the Western world.
In English, it is largely a meto ...
. The name also refers to a close relationship with ''
Auroraceratops
''Auroraceratops'', meaning "dawn horned face", is a genus of bipedal basal neoceratopsian dinosaur, from the Early Cretaceous (Aptian age) of north central China. The etymology of the generic name refers to its status as an early ceratopsian a ...
'', the "dawn ceratopian". The
specific name Specific name may refer to:
* in Database management systems, a system-assigned name that is unique within a particular database
In taxonomy, either of these two meanings, each with its own set of rules:
* Specific name (botany), the two-part (bino ...
means "short jaw" from the Greek βραχύς, ''brachys'' and γνάθος, ''gnathos'', in reference to the distinguishing short lower jaw.
''Helioceratops'' was discovered in a layer of the
Quantou Formation, dating from the
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 ...
-
Cenomanian
The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...
at the boundary between 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 ...
and 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 ...
, about a hundred million years old. It is known from its
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 ...
JLUM L0204-Y-3, a
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 ...
of the right lower jaw. The
paratype
In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype (biology), isotype ...
is specimen JLUM L0204-Y-4, a left
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 ...
of the upper jaw. Both fossils were discovered at a close distance from each other and indicate animals of about the same size; however, it could not be proven they belonged to a single individual.
Description
''Helioceratops'' was a relatively small animal. In 2010,
Gregory S. Paul
Gregory Scott Paul (born December 24, 1954) is an American freelance researcher, author and illustrator who works in paleontology. He is best known for his work and research on theropoda, theropod dinosaurs and his detailed illustrations, both l ...
estimated a length of 1.3 m (4.3 ft) and a weight of twenty kilogrammes.
[Paul, Gregory S. ''The Princeton Field Guide to Dinosaurs.'' Princeton University Press, 2010]
The describing authors established three distinguishing traits. They are
autapomorphies, unique derived qualities, in this case relative to all other neoceratopsians. The ''ramus'' or horizontal branch of the dentary is deep and short, the tooth row being but 60% longer than its maximal height. The facet of the front dentary contacting the lower process of the predentary is steeply inclined under an angle of 130° with the underside edge of the dentary. On the lower jaw teeth, the denticles and secondary vertical ridges are grouped asymmetrically relative to the primary ridge, with up to nine secondary ridges in front (
mesial
This is a list of definitions of commonly used terms of location and direction in dentistry. This set of terms provides orientation within the oral cavity, much as anatomical terms of location provide orientation throughout the body.
Terms
...
) of the main ridge and four secondary rides at it rear (
distal
Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provi ...
).
The number of teeth in the upper jaws is unknown. The lower jaws bear ten to eleven teeth. Their front teeth are relatively small, with a triangular cross-section. The rear teeth are larger and ovate in section, a derived trait.
Phylogeny
''Helioceratops'' was placed in the Neoceratopsia, in a moderately basal position, outside of the
Coronosauria. Its close relationship to the latter
clade
In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...
would indicate its origin in Asia.
Paleoecology
''Helioceratops'' was a herbivore. It may have shared its habitat with ''
Changchunsaurus''.
See also
*
Timeline of ceratopsian research
References
{{Taxonbar, from=Q2087008
Ceratopsia
Dinosaur genera
Albian dinosaurs
Taxa named by Pascal Godefroit
Fossil taxa described in 2009
Dinosaurs of China