A wooden figurehead carved in the shape of a sea monster that is over 500 years old has been lifted from Swedish seas as researchers surfaced treasures from a Danish warship.

The 15th century ship is that of Gribshunden, which caught fire on its way from Copenhagen to Kalmar, Sweden, and sank in 1495 – taking down with it its masthead, which is in the form of a mythical beast with lion-esque ears and a crocodile's jaw. Despite the fire, which ultimately submerged the ship, it still remains one of the best preserved wrecks, which the researchers state, is down to the fact that sea worms are deterred by the salty waters of the Baltic Sea.

Johan Ronnby, professor of marine archaeology at Sodertorn University, told Reuters: "Last time it looked at the world, Leonardo da Vinci and Christopher Columbus were still living. "It's a monster. It's a sea monster and we have to discuss what kind of animal it is. I think it's some kind of fantasy animal – a dragon with lion ears and crocodile-like mouth. I'm amazed, we knew that it should be a fantastic figure, but it was over our expectations when we saw it now. It's a fantastic figure, unique in the world."

The diving team is hopeful more of the wreck can be brought to the surface for further examination. Marcus Sandekjer, head of the Blekinge Museum, added: "The ship comes from a time just when Columbus was sailing across the ocean and Vasco da Gama also went to India, and this is the same period and we can learn very much about how the ships were made, how they were constructed since there are no ships left from this time.

"It's unique in the world and I think there are going to be more excavations around here and we're going to find some more unique objects. But this ... today is just fantastic."