作者：郑晓廷，邹晶梅，王孝理， 张晓梅，王岩 

　　摘要：根据发现于内蒙宁城早白垩世义县组地层中一件保存近乎完整的亚成年鸟类标本，报道了早期今鸟型类一新属、新种——陈氏天宇鸟(Tianyuornis cheni gen. et sp. nov.)。新属种与红山鸟科(高冠红山鸟Hongshanornis longicresta, 侯氏长腿鸟Longicrusavis houi及朝阳副红山鸟Parahongshanornis chaoyangensis)的特征最为相近，如体型大小相似，后肢明显长于前肢等；但也具有一系列与其他红山鸟科成员不同的特征，包括上下颌都保存有牙齿，齿骨直(特殊的“S”形齿骨曾被认为是红山鸟科鸟类的近裔特征)，胸骨后外侧突远端呈扇形扩展等。这些特征表明新标本为红山鸟科一新属种。该新属种的发现使红山鸟科成为已知种属分化最丰富的早白垩世今鸟类群。另外，新标本也丰富了红山鸟科鸟类许多新的重要形态学信息，证实这一支系鸟类仍保留有牙齿结构。 

　　关键词：内蒙古宁城，早白垩世，义县组，今鸟型类，红山鸟科 

　　卷期：52卷 02期 

New Information on Hongshanornithidae (Aves: Ornithuromorpha) from a new subadult specimen

ZHENG Xiao-ting, Jingmai K. O’CONNOR, WANG Xiao-li, ZHANG Xiao-mei, WANG Yan
 

Abstract We report on a new species of basal ornithuromorph bird, Tianyuornis cheni gen. et sp. nov., based on a nearly complete and articulated subadult individual from the Lower Cretaceous Yixian Formation in the eastern region of Nei Mongol, China. The new specimen shows features characteristic of the Hongshanornithidae (Hongshanornis longicresta, Longicrusavis houi, and Parahongshanornis chaoyangensis), such as small body size and elongate hindlimbs relative to their forelimbs, but it also possesses some unique features that support the erection of a new genus and species, including a straight dentary (a sigmoidal dentary was previously considered an autapomorphy of hongshanornithids), teeth preserved on both the upper and lower jaws, sternal caudolateral trabecula has a distinct fan-shaped expanded distal end. With the addition of this new taxon, Hongshanornithidae represents the most diverse recognized clade of Early Cretaceous ornithuromorphs. The new specimen reveals new important morphological information regarding the Hongshanornithidae and confirms the controversial presence of teeth in this clade.
Key words Ningcheng, Nei Mongol, China; Lower Cretaceous, Yixian Formation, ornithuromorpha, Hongshanornithidae