Giant marine reptile skull discovery reveals new evolutionary theories

CNN — The discovery of a giant marine reptile skull in the United States has revealed new theories about the speed of evolution and how quickly the process can produce diversity. The skull analysis was part of a larger research effort undertaken by an international team in order to understand how quickly body size evolved in ichthyosaurs when compared to the body size evolution of whales – another group of originally four-legged land vertebrates that returned to life in the sea, just like the ichthyosaur. The skull of the new ichthyosaur species Cymbospondylus youngorum is nearly 2 meters long and weighs 45 tonnes Stephanie Aramowiccz/Natural History Museum of Los Angeles County “Ichthyosaurs attained giant body size in a very short amount of time, evolutionarily speaking—just about 3 million years. “What this fossil discovery shows is that, if ecological conditions are just right and there’s a certain amount of environmental stability, evolution can proceed remarkably quickly.” Schmitz worked with a team of international researchers to analyze the fossil, identify the ichthyosaur as a new species, create a phylogenetic tree – a diagram which shows the evolutionary relationships among various biological species –and then led a computational analysis comparing the speed and type of the evolution of body size in ichthyosaurs to that of whales. Schmitz describes it as a “fish lizard.” The ichthyosaur fossil found in Nevada – which includes a preserved skull, shoulder and an arm similar to a flipper – was discovered in rocks that have preserved a cross section of fauna that existed approximately five million years after “the Great Dying.” That happened around 252 million years ago, when 81% of the world’s marine life went extinct.