Cracraft J
Department of Ornithology, American Museum of Natural History, New York, NY 10024, USA.
Proc Biol Sci. 2001 Mar 7;268(1466):459-69. doi: 10.1098/rspb.2000.1368.
The fossil record has been used to support the origin and radiation of modern birds (Neornithes) in Laurasia after the Cretaceous-Tertiary mass extinction event, whereas molecular clocks have suggested a Cretaceous origin for most avian orders. These alternative views of neornithine evolution are examined using an independent set of evidence, namely phylogenetic relationships and historical biogeography. Pylogenetic relationships of basal lineages of neornithines, including ratite birds and their allies (Palaleocognathae), galliforms and anseriforms (Galloanserae), as well as lineages of the more advanced Neoves (Gruiformes, (Capimulgiformes, Passeriformes and others) demonstrate pervasive trans-Antarctic distribution patterns. The temporal history of the neornithines can be inferred from fossil taxa and the ages of vicariance events, and along with their biogeographical patterns, leads to the conclusion that neornithines arose in Gondwana prior to the Cretaceous Tertiary extinction event.
化石记录曾被用于支持现代鸟类（新鸟亚纲）在白垩纪 - 第三纪大灭绝事件之后于劳亚大陆起源并辐射扩散，而分子钟研究则表明大多数鸟类目起源于白垩纪。本文利用一套独立的证据，即系统发育关系和历史生物地理学，来审视关于新鸟亚纲进化的这些不同观点。新鸟亚纲基部类群的系统发育关系，包括平胸鸟类及其近缘类群（古颚总目）、鸡形目和雁形目（鸡雁小纲），以及更高级的新鸟类（鹤形目、夜鹰目、雀形目等）的类群，都显示出广泛的跨南极分布模式。新鸟亚纲的时间演化历程可从化石分类单元和地理隔离事件的年代推断得出，结合其生物地理模式，得出的结论是新鸟亚纲在白垩纪 - 第三纪灭绝事件之前起源于冈瓦纳大陆。
