Contributions to Zoology, 71 (1/3) (2002)

The improbability of dorso-ventral axis inversion during animal evolution, as presumed by Geoffroy Saint Hilaire

J.A.M. van den Biggelaar , E. Edsinger-Gonzales , F.R. Schram

Faculty of Biology, Dept. of Experimental Zoology, University of Utrech Padualaan 8, 3584 CH Utrecht, Netherlands,

Smithsonian Marine Station, Smithsonian Institution 701 Seaway Drive, Fort Pierce, FL

Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam Mauritskade 57, 1092 AD, Amsterdam,

Keywords: amphistomy, axis inversion, deuterostomes, spiral cleavage, protostomes, gastrulation