封面说明： 早白垩世基干尾综骨类孔子鸟目复原图。孔子鸟目是早白垩世鸟类中具有角质喙和尾综骨的最原始的鸟类类群之一。在过去近 20 年的研究历史中，千余件孔子鸟类标本被发现，数目多过其他中生代鸟类和非鸟类恐龙。目前，共计 4 个属， 10 个种被先后归入到孔子鸟目中，然而这些属种的分类位置是否有效尚不清楚，使得孔子鸟目成为了一个 “ 分类垃圾桶 ”。对已发表的所有孔子鸟类属种进行详细对比研究，证实了其中多数属种的鉴定特征有误，这些特征或受保存的影响，或代表了种内和个体发育的变化，亦或广泛分布在孔子鸟类或基干鸟类中，而并不能成为这些属种建属或建种的依据。对所有已报道的孔子鸟目的分类厘定认为，目前孔子鸟目共包括 1 科、 3 属、 4 种，分别是圣贤孔子鸟、杜氏孔子鸟、横道子长城鸟和郑氏始孔子鸟，这些属种各自的鉴定特征也得到了修正。详见王敏等人文 (p. 1)。 ( 绘图： Michael Rothman)

Cover image: Life reconstruction of the Early Cretaceous stemward pygostylian Confuciusornithiformes. The Confuciusornithiformes is a basal clade of Early Cretaceous birds that includes the oldest and most basal birds with a toothless beak and an abbreviated bony tail. Over the last two decades, thousands of specimens have been collected, more than for any other group of Mesozoic birds or non-avian dinosaurs. Ten species separated into four genera have been erected with limited taxonomic phylogenetic scrutiny, making the Confuciusornithiformes like a "taxonomic garbage can". Wang et al. perform a comparative study of these ten species, and demonstrate that most of these taxa were originally diagnosed by characters that prove to be either preservational artifacts, intraspecifc variations, subject to ontogenetic variation, or widely distributed among the Confuciusornithiformes or a more phylogenetically inclusive group. The taxonomic reappraisal of published materials indicates that the Confuciusornithiformes consists of one family, three genera, and four species: Confuciusornis sanctus, Confuciusornis dui, Changchengornis hengdaoziensis, and Eoconfuciusornis zhengi, for which revised diagnoses are provided. See details in the paper of Wang et al. (p. 1). (Illustrated by Michael Rothman)