Did animal evolution begin with a predatory lifestyle?

Were the first animals predators or filter feeders like the sponges living in today's oceans? And what role did symbiosis with algae play, as with reef-building corals? Surprising findings by a research group led by Prof. Dr. Thomas W. Holstein of Heidelberg University on the development of sea anemones suggest that a predatory lifestyle molded their evolution and had a significant impact on the origin of their nervous system.