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
Canon of the Mass Canon of the Mass Canon of the Mass (Latin: "Canon Missæ", "Canon Actionis") is the name given in the Roman Missal, from the first typical edition of Pope Pius V in 1570 to that of Pope John XXIII in 1962, to the part of the Mass of the Roman Rite that begins after the Sanctus with the words "Te igitur". All editions preceding that of 1962 place the indication "Canon Missae" at the head of each page from that point until the end of the Mass; that of 1962 does so only until the page preceding the Pater Noster and