BioEssays 7/2009

Cover Photograph: (Left) top: Cricocosmia jinningensis , a nematomorph worm. This species is known from thousands of specimens. The anterior proboscis, armed with spines, and the dark‐coloured gut, are often clearly seen. It is known only from the Lower Cambrian of Yunnan Province. Middle: Hallucigenia fortis , a lobopodian, is envisaged to have had an epibenthic, crawling mode of life. The species is confined to the Lower Cambrian of Yunnan, but the genus is also known from the Middle Cambrian Burgess Shale of British Columbia, and may also be present in the Kaili Lagerstatte of Mid‐Cambrian age from Guizhou Province, China. Bottom: Yunnanozoon lividum , an enigmatic form. This animal may have been a deposit feeder. It has only been recorded from the Chengjiang biota. Right (background photo, lightened): Naraoia spinosa , an arthropod with an unmineralized cuticle, is often preserved with distinct traces of its alimentary system. The species has been unrecorded outside the Chengjiang fauna. The cover photos are used with the generous permission of Professor Derek Siveter, University of Oxford, from the book: The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life, by Xian‐guang Hou, Richard Aldridge, Jan Bergstrom, David Siveter, Derek Siveter, Xiang‐Hong Feng, Wiley‐Blackwell, ISBN: 978‐1‐4051‐0673‐3 and ISBN 978‐14051‐6719‐2 (pbk).