Arthropods have segmented bodies and jointed legs. Opabinia had a clearly segmented body but did it have jointed legs? Look closely at the fossils and reconstructions above. Each body segment has two pairs of flaps. One pair was a simple flap and was probably used for swimming but these were not jointed. The second pair looks striped in the reconstruction above. These stripes are the imprints of gill layers and were used for getting oxygen from the water.