侏罗纪的花化石与被子植物起源

Jurassic flower fossils and the origin of angiosperms

理解被子植物的历史对于人们了解现代被子植物之间的关系十分重要。以前欧美古植物学家认为,被子植物的历史不会早于白垩纪,使得被子植物看起来似乎是在白垩纪早期突然爆发的。但是分子钟和系统分析显示,被子植物应当早在三叠纪,至少在侏罗纪就已经出现了,但是问题的关键是相应化石证据的缺失。因此侏罗纪的花化石成为解决两个学派之间争斗的关键证据。本文简要地介绍了产出于中国辽西同一地层的、侏罗纪的三个被子植物属种及其特征,确认了被子植物在侏罗纪的存在,提出了新的被子植物雌蕊同源性理论,并为下一步植物系统学的发展打下了坚实的基础。

Understanding on the history of angiosperms is hinged with our appreciation of the relationship among extant angiosperms. Formerly European and American palaeobotanists believed that angiosperms cannot be older than the Cretaceous, leaving the origin of angiosperms as if a sudden explosion during the Early Cretaceous. But molecular clock and systematic analysis suggested that angiosperms should have been in place in the Triassic or at least the Jurassic, but this point of view lacked fossil support. Therefore the fates of angiosperm evolution hypotheses are hinged with the existence of fossil flowers in the Jurassic. Herein we introduce three taxa of angiosperms from a single Jurassic fossil locality in western Liaoning, China, confirming the existence of angiosperms in the Jurassic, advancing a new theory on the homology of angiosperm gynoecium, and paving the road for further development of plant systematics.