黑龙江嘉荫晚白垩世一鸭嘴龙亚科恐龙齿骨化石

鸭嘴龙科(Hadrosauridae)化石根据头骨特征等被划分为鸭嘴龙亚科(Hadrosaurinae,无头冠)和赖氏龙亚科(Lambeosaurinae,有头冠)。黑龙江嘉荫龙骨山晚白垩世渔亮子组保存了丰富的鸭嘴龙化石,其中黑龙江满洲龙Mandschurosaurus amurensis(Riabinin,1925)是最早在中国发现的恐龙,属鸭嘴龙亚科;嘉荫卡龙Charonosaurus jiayinensis(Godefroit et al,2000)也是在这里发现的,属赖氏龙亚科。本文描述了采自嘉荫龙骨山的部分左齿骨化石和一些牙齿化石,新的化石明显属于鸭嘴龙亚科,主要特征为:齿骨每个牙列有5个以上的牙齿,牙冠边缘小锯齿由乳头状小瘤构成。新发现的牙齿牙冠上发育有明显的第二、三副脊,这在鸭嘴龙中是罕见的。新发现的化石明显不同于产于同一地点的嘉荫卡龙,但由于黑龙江满洲龙模式标本没有保存牙齿,因此暂不能与之充分对比。

A hadrosaurine dentary from Upper Cretaceous of Jiayin,Heilongjiang

Abstract: Hadrosauridae is taxonomically subdivided into the Hadrosaurinae and Lambeosaurinae based mainly on the skull characteristics. Hadrosaurid fossils are particularly abundant in Upper Cretaceous of Yuliangzi Formation from Longgushan of Jiayin, Heilongjiang. Mandschurosaurus amurensis (Riabinin, 1925) , the first dinosaur fossil found from China, was discovered in this locality and belongs to hadrosaurinae. Charonosaurus jiayinensis (Godefroit et al. , 2000) was also excavated here and belongs to lambeosaurinae. The authors describe a partial left dentary with dozens teeth from the Longgushan, and this new fossils clearly belong to hadrosaurinae. Because it is characterized by the following synapomorphies: 5 teeth ormore in each alveolus of the dentary and dentary marginal denticles reduced to small papillae along the dorsal half of the crown. Well developed secondary and tertiary ridges on the lingual side of the dentary crowns are unusual in hadrosaurids. The newly discovered fossil is obviously different from Charonosaurus jiayinensis occurred in the same place, while the comparisons with Mandschurosaurus amurensis are difficult, because the dentary referred to the holotype of this taxon lacks teeth in preservation.