Trichoplax adhaerens: discovered as a missing link, forgotten as a hydrozoan, re-discovered as a key to metazoan evolution - Syed, T.; Schierwater, B. (Vie Milieu, 2002)
Trichoplax adhaerens is more simply organized than any living metazoan. After its original description by FE Schulze 1883, it attracted particular attention because it possibly possessed the basic and ancestral state of metazoan organization. The interest of zoologists and evolutionary biologists suddenly vanished for more than half a century when Trichoplax was claimed to be an aberrant hydrozoan planula larva. Recently, Trichoplax has been rediscovered as a key species for unraveling early metazoan evolution. Hox genes and whole genome sequencing promise insights into the genetics underlying the origin and development of basal metazoan phyla. We here review the history of research on Trichoplax, and provide a modern interpretation of special Trichoplax features in an evolutionary context.