Diagram of the many types of turtles that survived the K/T extinction event. The skulls of these turtles are illustrated (as viewed from above) as are their fossil record (thick blue bars) and evolutionary relationships (thin lines connecting bars). The red line marks the extinction event, and is matched with the photographic of the geologic section in the background. The rocks below the red line were deposited during the Age of Dinosaurs (Mesozoic Era), whereas those above the line were deposited at the beginning of the Age of Mammals (Cenozoic Era). Note that eight different lineages of turtles survived the event, while only two went extinct at the event. Image courtesy of Erik Freeman. |