Question: what were the the first animals on earth?

Charlotte Brassey answered on 13 Jun 2012:

Life first appeared on the earth in the oceans, rather than on land. At first, creatures would have been made up of only a single cell, and then later on multicellular animals appeared. One of the most widespread organisms during this time was call ‘cyanobacteria’ or blue-green algae, and it’s basically identical to the green pond scum you see floating on top of duck ponds today!

The first official ‘animals’ (if you don’t include sponges and corals etc) appeared around 550 million years ago, and included species similar to starfish, mussels, shrimp and even trilobites (which look like giant aquatic woodlouse!)