Genesis 2008 Nov;46(11):580-6
Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK.
Since the discovery of the marine worm Xenoturbella bocki in 1915 by Sixten Bock and its first published description by Einar Westblad (Westblad,1949, Arkiv Zoologi 1:3-29), Xenoturbella was generally allied to the turbellarian flatworms, perhaps most closely to acoelomorphs. In 1997, however, analyses of ribosomal DNA (Norén and Jondelius, 1997, Nature 390:31-32) and developing oocytes (Israelsson, 1997, Nature 390:32) [and, subsequently, embryos (Israelsson, 1999, Proc R Soc Lond B 266:835-841)] recovered from Xenoturbella specimens led to the surprising conclusion that it was in fact a highly degenerate bivalve mollusc. Bourlat et al. Read More