Placozoan Taxonomy

• Applicant: Professor Dr. Bernd Schierwater
• Subject Area: Systematics and Morphology (Zoology)
• Term: from 2009 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 129047966

In the first three years of funding we have shown that the formally monotypic phylum Placozoa (the only valid species being Trichoplax adhaerens) harbors at least 22 distinct lineages (haplotypes), which are genetically, morphologically and ecologically well separated. Thus we have erected 21 new species hypotheses, which we rigorously test by an integrative dynamic circle approach. For the latter we collect as much information as possible from a variety of molecular and organismal characters. The preliminary data suggest deep branching patterns between the 22 haplotypes and the existence of several higher taxonomic clades. Thus the phylum Placozoa is in dire need for a rigorous taxonomic revision. This provides us with the completely unique opportunity to use this phylum as a tabula rasa example to explore classical approaches to taxonomy using Linnaean (rank based) principles and another newly proposed (and yet controversial) approach to taxonomy called the Phylocode. Finishing up data collection and performing the systematic analyses is expected to reveal up to 21 new placozoan species and a genuinely new taxonomy for the phylum Placozoa.

• DFG Programme: Research Grants