What is the phylogeny of sponges?

Sponges (phylum Porifera) are a diverse taxon of benthic aquatic animals of great ecological, commercial, and biopharmaceutical importance. They are arguably the earliest-branching metazoan taxon, and therefore, they have great significance in the reconstruction of early metazoan evolution. read more

Some form of the Mastigophora among the protozoans specialised into different functions of a simple sponge body, so that the animal became a sessile,but at the same time through the help of mastigos, could filter in the food matter. read more

The evolution of complexity The traditional view of the issue postulates that the sponges were the first group to diverge from the lineage that gave rise to all other animals -- in other words, Porifera are the sister group of all other animal species. read more