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

Like other mosasaurids, M. wakayamaensis has a dolphin-like body with four paddle-like fins, 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 mosasaurid species. However, what confuses researchers the most is the size of this mosasaurid's hind fin, which is even longer than its front fin. This condition is not only the first to occur in a mosasaurid, but also very rare in all living and extinct aquatic species.

Almost all swimming animals have the largest fins in the front part of their bodies, which help them navigate through water. Having larger fins in the back of the body would be like driving a car with rear wheels instead of front wheels, which would make it more difficult to turn quickly. "We lack modern analogies that have body morphology like this - from fish, penguins, to turtles," said Konishi.

Researchers speculate that instead of using their back fins to rotate, M. wakayamaensis directs them upwards or downwards to quickly dive or ascend through the water column, which may help them become skilled hunters. The dorsal fin could facilitate the creature's rotation, potentially countering the additional resistance from the back fin, they added.

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

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