Deep Root of the Modem Animal Diversity

摘要

Beautifully preserved organisms from the Lower Cambrian Maotianshan Shale in central Yunnan,southem China,document the sudden appearance of diverse metazoan body plans at phylum or subphylum levels,which were either short-lived or have continued to the present day.These 530 million year old fossil representatives of living animal groups provide us with unique insight into the foundations of living animal groups at their evolutionary roots.Among these diverse animal groups,many including ctenophores,priapulids,sipunculans,arrow worms,tunicates,linguloids,are conserva-tive,changing very little since the Early Cambrian.