作者：李 岩，张玉光，周忠和，李志恒，刘 迪，汪筱林

摘要：继1984年首次报道甘肃玉门昌马地区发现的早白垩世甘肃鸟及2006年记述多件甘肃鸟标本以来，再次对发现于2004~2006年间的9件甘肃鸟标本进行形态的详细观察，补充描述甘肃鸟新的骨骼特征，包括侧面保存的胸骨，有较完整的镰刀形龙骨突及胸骨的背侧特征等；部分前肢的骨骼上有位于关节位置、呈短长方形的尺腕骨和桡腕骨；指式“2−3−1”, 小指骨的爪节完全退化消失；后肢各趾中第1趾节最长，趾爪短小并弯曲度小；第I趾相对较短、细弱，与其他趾相对握；第III趾粗壮，略短于第IV趾。在胫跗骨和跗跖骨关节处保存有鳞片状的皮肤印痕，趾骨间有蹼的印痕。通过指示性骨骼测量的三元分析，得出甘肃鸟是一类善飞的潜水鸟类，其习性接近于部分现生的鸭科成员，与之前有关甘肃鸟生活习性的推测较为接近。

关键词：早白垩世，甘肃鸟，新材料，习性

卷期：49卷 04期

NEW MATERIAL OF GANSUS AND A DISCUSSION ON ITS HABIT

LI Yan, ZHANG Yu-Guang, ZHOU Zhong-He, LI Zhi-Heng, LIU Di, WANG Xiao-Lin

Abstract  Some newly discovered postcranial material of Gansus yumenensis are described, adding to our understanding of the skeletal anatomy of this basal ornithurine. Such anatomical features include a laterally exposed sternum with a sickle-shaped keel, the ulnare with small metacarpal incision, complete loss of ungual of the minor digit, and manual phalangeal formula of “2−3−1”, as well as some more detailed features of the leg bones. The new material not only provided additional evidence of interdigital web but also preserved some scale-like skin impressions near the joint between the tibiotarsus and tarsometatarsus. A statistic analysis of the measurements of the sternum and major elements of the leg of Gansus further supports the hypothesis that this bird was a volant and diving bird, similar to that of extant ducks.
Key words  Early Cretaceous, Gansus, new material, habit