Here's an article from ScienceDaily.
New Tree Of Life Divides All Lower Metazoans From Higher Animals, Molecular Research ConfirmsThere's so much wrong with this description that one hardly knows where to begin. Ryan Gregory highlighted the worst parts at Lower and basal.
ScienceDaily (Jan. 27, 2009) — A new and comprehensive analysis confirms that the evolutionary relationships among animals are not as simple as previously thought. The traditional idea that animal evolution has followed a trajectory from simple to complex—from sponge to chordate—meets a dramatic exception in the metazoan tree of life.
New work suggests that the so-called "lower" metazoans (including Placozoa, corals, and jellyfish) evolved in parallel to "higher" animals (all other metazoans, from flatworms to chordates). It also appears that Placozoans—large amoeba-shaped, multi-cellular animals—have passed over sponges and other organisms as an animal that most closely mirrors the root of this tree of life.
Do NOT use the words "higher" and "lower" to describe biological species. This is a mistake that many scientists make so we can't blame the journalists1 for this one.
1. I wonder what Graham Lawton thinks about this tree of life?