多刺甲龙亚科恐龙在亚洲的首次发现

First discovery of polacanthine ankylosaur dinosaur in Asia

基于采自兰州-民和盆地下白垩统河口群中的化石(一前中部尾椎,三根背肋,一个近乎完整的左髂骨和若干甲片)建立恐龙一新属种:金城洮河龙(Taohelong jinchengensis gen.et sp.nov.)。洮河龙具有三个自有裔征:前中部尾椎神经孔呈倒立的梯形,髂骨前突外侧缘背视呈翻转"S"形及荐盾由大小不一排列无规则的甲片愈合而成。分支系统分析表明洮河龙属甲龙类结节龙科中的多刺甲龙亚科,并且和发现于英国早白垩世巴雷姆期的Polacanthus foxii是姐妹群。洮河龙代表了多刺甲龙亚科化石在亚洲的首次发现,也再次表明兰州-民和盆地的河口群蕴含着一个丰富而独特的恐龙化石组合。

A new dinosaur, Taohelongjinchengensis gen. et sp. nov., is described based on material （a proximo-middle caudal vertebra, three dorsal ribs, an almost complete left ilium, and several armors including a partial sacral shield） from the Lower Cretaceous Hekou Group in Lanzhou-Minhe Basin, north-central China. Taohelong jinchengensis possesses three autapomorphies： neural canal of proximo-middle caudal inverted trapezium, lateral edge of preacetabular process inverted ＂S＂ -shaped in dorsal view, and sacral shield composed of various- sized and irregularly-arranged osteoderms. Cladistic analysis shows that Taohelong is a member of polacanthine nodosaurid ankylosaur, and is the sister taxon of Polacanthusfoxii from the Early Cretaceous Barremian of England. Here Polacanthinae is defined as the most inclusive clade containing Polacanthus foxii Owen, 1865 but not Ankylosaurus magniventris Brown, 1908 or Panoplosaurus mirus Lambe, 1919. Taohelong represents the first occurrence of polacanthine in Asia, and indicates again the existence of a rich and unique dinosaur assemblage in the Lower Cretaceous Hekou Group in the Lanzhou-Minhe Basin.