Therefore, paleontologists think it probably lived in shallow, weed-choked swamps, the legs adapted to some other function than walking on land. Also, there is a change in the arrangement of teeth from previous types. At that period, for the first time, deciduous plants were flourishing and annually shedding leaves into the water, attracting small prey into warm oxygen-poor shallows which were difficult for larger fish to swim in. Both "Ichthyostega" and "Acanthostega" may heve breathed air by sticking their heads above the water in these shallows.