Rhizodus was a very large freshwater sarcopterygian that lived in swamps and rivers all over pangea the entire Carboniferous period. Rhizodus would have been one of the largest fish in the carboniferous waters. It was a macropredator, feasting on the temnospondyls and the lepospondyls wherever it lived or swam. It had very large fangs at the opening of its mouth measuring up to 22 centimetres in length and gradually declining in length as the teeth went back towards the mouth.
Unlike other large sarcopterygians around at the time, Rhizodus's teeth were designed to rip into small to medium sized amphibians whereas others swallowed their prey whole after ambushing them.