The Lost Worlds of Planet Earth Ortelius hypothesized the idea that land masses may have been connected in the past, Alfred Wegener who hypothesized the idea of a super-continent Pangaea and continental drift despite the prevailing idea of flooded land-bridges at the time, and Bruce C. Heezen and Marie Tharp who discovered the Mid-Atlantic Ridge that supported the theory of plate tectonics. Tyson describes how the landmasses of the earth lay atop the mantle, which moves due to the motion and heat of the earth's outer and inner core. Tyson moves on to explain the asteroid impact that initiated the Cretaceous–Paleogene extinction event, leaving small mammals
Backs to the Land The three women are Daphne, Cockney Jenny and Jewish, down to earth Shirley. They end up at Crabtree Farm in Clayfield, Norfolk. The owner is Tom Whitlow, and his sons are Roy and Eric. All three series of "Backs to the Land" have been released on 28 June 2010 and on 6 February and 9 April 2012. A 3-disc set of the complete series is scheduled to follow at some point. Backs to the Land Backs to the Land is a British sitcom that aired on ITV from 1977 to 1978. Starring Philippa Howell, Terese Stevens and Marilyn Galsworthy, "Backs