The cetacean that washed up dead on Banjaard Beach near Kamperland, Zeeland, on Friday was a rare Risso’s dolphin, the Dutch Marine Animal Rescue Team (RTZ) announced.

The animal was first thought to be a Beluga whale, but research by Utrecht University’s Faculty of Veterinary Medicine confirmed that it was a Risso’s dolphin, also called a grey dolphin, RTL Nieuws reported.

The last time a Risso’s dolphin stranded in the Netherlands was in the 1970s. Belugas, on the other hand, have been spotted several times off the Dutch and Belgian coasts this year.

The Utrecht researchers confirmed the animal’s species by researching its skull, RTZ said. “Due to the decay, there were no teeth left in the mouth, but four to five cavities were visible in the front part of the lower jaw, whereas no cavities were present in the upper jaw. The grey dolphin is the only species this fits. Belugas have teeth in both the upper and lower jaws,” the rescue team said.