Can we ever identify the Urmetazoan

Abstract

Unraveling the root of the metazoan tree of life has been a difficult task since the time of Haeckel and the invention of phylogenetics. Even considerable amounts of recent molecular data have not provided a generally accepted answer. Here, we review the major problems of this phylogenetic conundrum and provide some directions for solving it. © The Author 2007. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved.