Holozoa

Holozoa is a group of living things that includes animals, and some single-celled relatives of animals. It excludes fungi. "Holozoa" is also an old name for the tunicate genus "Distaplia". 
Holozoa is a clade: a group of plants or animals with a common ancestor. It has all organisms close to animals."
An example of a well-known holozoan is the choanoflagellate, which looks a lot like the cells of a sponge. "Proterospongia" is an example of a choanoflagellate that might give clues as to how sponges evolved.
Evolution.
The phylogenic tree (evolution tree) below shows how clades broke into newer clades. This includes Holozoa.