"Dream - Scientists in Japan have discovered the remains of an almost complete ancient sea monster the size of a great white shark. This creature is believed to have been a terror in the ancient oceans. The prehistoric predator, which researchers have named “blue dragon,” has an unusual body shape that distinguishes it from its extinct relatives and unlike any other living creatures that exist today."

"Like other mosasaurs, M. wakayamaensis has a dolphin-like body with four paddle-like flippers, an alligator-shaped snout, and a long tail. It also has a dorsal fin like a shark or dolphin, which is not seen in other mosasaurus species. However, what confuses researchers the most is the size of the mosasaurus's rear flippers, which are even longer than its front flippers. This condition is not only the first of its kind in mosasaurs but is also very rare among all living and extinct aquatic species."

"Almost all swimming animals have the largest fins at the front of their bodies, which helps them navigate the water. Having larger fins at the back of the body would be like driving a car using the rear wheels instead of the front wheels, which would make it harder to turn quickly. “We lack modern analogies that have such body morphology – ranging from fish, penguins, to turtles,” said Konishi."

The researchers suspect that instead of using the tail fin to turn, M. wakayamaensis directs it upwards or downwards to quickly dive down or rise through the water column, which may help them become skilled hunters. The dorsal fin could make it easier for the creature to turn, which might counteract the extra drag from the tail fin, they added.

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This opens up a lot of worms that challenge our understanding of how mosasaurs swam,” said Konishi. M. wakayamaensis is nearly the same size as a great white shark (Carcharodon carcharias), which is about 16 feet (4.9 meters) long. However, other species can grow up to 56 feet (17 meters), longer than a school bus.

"Mosasaurus appeared about 100 million years ago and died around 66 million years ago along with non-avian dinosaurs after a large asteroid struck Earth. According to researchers, during the last 20 million years of its existence, this fearsome sea lizard was equivalent to Tyrannosaurus rex in the waters and was at the top of the food chain, partly due to the loss of other top marine predators such as ichthyosaurs and pliosaurs. (Livescience)"