A new basal neoceratopsian dinosaur, Helioceratops brachygnathus gen. et sp. nov., is described from the Quantou Formation （late Early Cretaceous or early Late Cretaceous） in the Liufangzi locality （Jilin province,...A new basal neoceratopsian dinosaur, Helioceratops brachygnathus gen. et sp. nov., is described from the Quantou Formation （late Early Cretaceous or early Late Cretaceous） in the Liufangzi locality （Jilin province, China）. Helioceratops differs from other basal neoceratopsians with its deep dentary 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 and Yamaceratops, Helioceratops represents one of the most derived non-coronosaurian neoceratopsians. The palaeogeographical distribution of basal neoceratopsians appears 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 Coronosanria.展开更多
The middle Cretaceous Kazhdumi Formation,with a thickness of 222 m,belongs to the Bangestan Group and occurs in the Zagros folded zone in southwest Iran.The lower boundary with the Dariyan Formation is disconformable,...The middle Cretaceous Kazhdumi Formation,with a thickness of 222 m,belongs to the Bangestan Group and occurs in the Zagros folded zone in southwest Iran.The lower boundary with the Dariyan Formation is disconformable,which is recognized by iron oxides and glauconite.The recognized microfossils are Valvulammina sp.,Scandonea sp.,Daxia cenomana,Choffatela sp., Pseudolituonella reicheli and calcareous algae-Lithocodium aggregation（which belongs to the Sarvak Formation）,representing the beginning of Cenomanian.Other microfossils are：Ammobaculites goodlandensis,Marsonella trochus,Hemicyclammina sigali,Praechrysalidina infracretacea,Orbitolina gr.concava,Orbitolina（conicorbitolina）conica,Orbitolina subconcava,Salpingoporella sp.,Trinocladus tripolitanus,Trinocladus sp.,Permocalculus irenae and Dissocladella deserta.These microfossils can be classified into five assemblage zones.展开更多
基金the National Infrastructure of Mineral Rock and Fossil Resources for Sciences and Technology Program(2005DKA21405-7)the Science and Technology Research and Development Program of Changchun City(04-07SF092)supported by an FNRS grant.
文摘A new basal neoceratopsian dinosaur, Helioceratops brachygnathus gen. et sp. nov., is described from the Quantou Formation （late Early Cretaceous or early Late Cretaceous） in the Liufangzi locality （Jilin province, China）. Helioceratops differs from other basal neoceratopsians with its deep dentary 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 and Yamaceratops, Helioceratops represents one of the most derived non-coronosaurian neoceratopsians. The palaeogeographical distribution of basal neoceratopsians appears 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 Coronosanria.
文摘The middle Cretaceous Kazhdumi Formation,with a thickness of 222 m,belongs to the Bangestan Group and occurs in the Zagros folded zone in southwest Iran.The lower boundary with the Dariyan Formation is disconformable,which is recognized by iron oxides and glauconite.The recognized microfossils are Valvulammina sp.,Scandonea sp.,Daxia cenomana,Choffatela sp., Pseudolituonella reicheli and calcareous algae-Lithocodium aggregation（which belongs to the Sarvak Formation）,representing the beginning of Cenomanian.Other microfossils are：Ammobaculites goodlandensis,Marsonella trochus,Hemicyclammina sigali,Praechrysalidina infracretacea,Orbitolina gr.concava,Orbitolina（conicorbitolina）conica,Orbitolina subconcava,Salpingoporella sp.,Trinocladus tripolitanus,Trinocladus sp.,Permocalculus irenae and Dissocladella deserta.These microfossils can be classified into five assemblage zones.
