- Peter Holland
‘Deuterostomes III: vertebrates on land’ considers the chordates of the ‘sarcopterygian’ group. There are three groups of living lobe-finned vertebrates — coelacanths, lungfish, and the tetrapods, the latter including all the land vertebrates including humans. The single evolutionary lineage of vertebrates that overcame the challenges of living on dry land gave rise to all of the land vertebrates still living today: amphibians, reptiles, birds, and mammals. To live successfully on land, animals must be able to obtain oxygen from air, find and catch food on land, carry their body weight in a medium far less supportive than water, propel themselves along land, and avoid drying out through excessive loss of moisture.