Discover which land mammals turned to the sea in search of food and adapted to their equatic environment and consider the Cretaceous extinction and rise of the great sea mammals.

First swimmers -- Ecological overview -- School of swimming reptiles -- Placodonts-the shell seekers -- Between the land & the sea -- Giants of the sea -- Range of pliosaurs -- Elasmosaurs-the long necks -- Elasmosaur lifestyle -- Ichthyosaurs-the fish lizards -- Range of ichthyosaurs -- Ichthyosaurs-dispelling a myth -- Mosasaurs -- Crocodiles -- What came next? -- Did you know? --More books to read.