[D] Helioceratops brachygnathus [sG] [T]
Jin, Chen, Zan, Godefroit 2009
Cretaceous Early Cretaceous Late
Ornithischia Genasauria Cerapoda Marginocephalia Ceratopia Neoceratopia
Quantou Formation, Liufangzi locality, Jilin Province, China
Helioceratops brachygnathus differs from other basal beoceratopsians with its deep dentatry ramus, its steeply-inclined ventral predentary facet, its heterogeneous dentary crowns, and by the denticles and secondary ridges asymmetrically distributed on either side of the primary ridge on its dentary teeth. Along with Auroraceratops rugosus and Yamaceratops dorngobiensis, Helioceratoops represents one of the most derived non-coronosaurian neoceratopsians. The palaeogeographical distribution of basal neoceratopsians appaers limited to northern China and southern Mongolia in the current state of our knowledge. It is therefore probable that this region constituted the birthplace for more advanced Late Cretaceous Coronosauria.
In ancient Greek mythology, Helios was the god of the sun, who drove his golden chariot across the sky from the east to the west every day. He was also the brother of Eos (\\\"the dawn\\\"). This generic name suggests an oriental origin for this neoceratopsian, which is closely related to Auroraceratops. Brakhus, Greek for short and Gnathos Greek for \\\"jaw\\\".
JLUM L0204-Y-3, a right dentary in the Jilin University Museum, Changchun, Jilin Province, China.
JLUM L0204-Y-4, a left maxilla. Although both specimens were found close to each other in the same bone-bearing layer and are of approximately the right size to be associated, it cannot be strictly proven that they belong to the same individual. In any case, we interpret them to be conspecific, pending evidence to the comtrary.
Non-coronosaurian Neoceratopia is characterized by the following autapomorhies: dentary ramus deep with a ratio \\\"length of the tooth row/maximum height of dentary ramus\\\" =1.6; ventral predentary facet more vertical than in other bassal neoceratopians, forming an angle of approxiamtely `130 degrees with the ventral border of the dentary ramus; and denticels and secondary ridges asymetrically ditributed on either side of the primaary ridge on the dentary teeth with up to nine secondary ridges on the mesial half and up to four in the distal half.