基于骨骼羟磷灰石稳定碳同位素组成分析的孔子鸟食性研究

孔子鸟在早期鸟类食性研究中有着极其重要的作用，因其是目前已知最早无牙、代之以角质喙的鸟类，且处于有牙早期鸟类或带羽毛恐龙向进步的、长有角质喙鸟类过渡的重要阶段。然而，迄今发现的孔子鸟的食物或其它类似残留证据极少，不足以清晰地认识其食性，类似问题也存在于其它早期鸟类的相关研究中，从而制约了对早期鸟类食性的深入了解。鸟类骨骼羟磷灰石稳定碳同位素组成可有效记录其摄取的食物信息，其衍生的实验手段已被成功地应用于恐龙、较进步的古鸟类以及现生鸟类等动物的食性研究中。因此，本项目拟对孔子鸟的骨骼羟磷灰石稳定碳同位素组成进行分析，并将结果与食性较明确的同时代的会鸟和燕鸟的骨骼羟磷灰石稳定碳同位素组成进行对比分析，以判定孔子鸟的食性。本项目是首次利用地球化学手段开展早期鸟类孔子鸟的食性研究，将为早期鸟类食性演化研究提供重要证据，同时有望为早白垩世热河生物群其它动物的类似研究探索出一条行之有效的方法。

Confuciusornithid birds play a key role in understanding early bird's diet, because they are the earliest known birds with beak, rather than teeth, two preliminary feeding organs coexisted in the transitional period from primitive toothed birds or feathered dinosaurs to late beaked birds. However, a few known food fossils or other remains alike could not provide enough evidences to clearly understand confuciusornithids' diets, a similar situation exists in other early birds, both limited our knowledge on the early birds’ diets. The stable carbon isotope composition (δ13C) of birds’ bone hydroxylapatite could effectively record birds' diets, and the derived food-analyzing method has been successfully adopted in dinosaurs, the late or extant birds, or other animals. In this program, we would analyze the confuciusornithid's bone hydroxylapatite δ13C first, then compare the results to those of sapeornithids and yanornithids, two other primitive birds whose diets appear more obvious than that of confucusornithids, and to deduce the diet of confuciusornithids finally. The method's first attempt carrying out to confuciusornithids is expected to provide important evidence for the evolution of early birds’ diets, and to be applied to those of other animals in Early Cretaceous Jehol Biota.