The carcass of a mysterious marine creature with a furry tail and long beak that washed ashore off the coast of Russia has been identified.

The carcass, which resembled a dolphin, baffled scientists at first and created a buzz on social media around the globe after it was found on a beach on Russia's Far East island of Sakhalin a week ago. But scientists have finally confirmed that it belonged to a cub of a beaked whale, which is common in the region.

Nikolay Kim, deputy head of the forecasting department of Sakhalin Research Institute of Fisheries and Oceanography, confirmed this after a meeting with the scientists.

"We have gathered a group of scientists. We studied all the versions and came to the conclusion that the fossils found ashore belong to a whale cub," Kim said, according to RT News via Sakhalin Media.

When photos of the carcass were uploaded to social media after its discovery, it sparked shocking reactions from netizens because it had a furry tail.

Some scientists and netized theorized that the remains belonged to a Ganges River dolphin, but an expert insisted it couldn't be possible because of the presence of fur.

But scientists have solved the mystery. Whales and dolphins are mammals and share similar characteristics with other mammals, one of which is the presence of hair. However, hair on dolphins or whales eventually disappear as they mature.

The Siberian Times recently reported that Sergei Kornev, a fellow at the Kamchatka Research Institute of Fisheries and Oceanography, said the fur found on the carcass was nothing more than just "bristle," which would appear whenever a dead animal remained in the water for a long time and ended up decomposed by microorganisms.

"It's an aggressive environment. Soft tissue can be washed away and it looks like 'bristle' and in fact, is neither fur nor hair," Kornev explained.