The 2-metre-long mammal weighing 50kg appeared on the beach in Łazy, close to the seaside resort of Mielno.
The dentary bone with two rows of cusps on molars and double-rooted teeth is the oldest of its type in the world and belonged to a new early-diverging haramiyid species from the late Triassic period named Kalaallitkigun jenkinsi (Greenlandic for 'tooth from Greenland') by its discoverers.
According to the project’s team leader, the pioneering early ‘rabbit’ brain research is “very important for the evolutionary biology of the entire Euarchontoglires group, including humans.”
The ancient remains consisting of the front part of the skull and both horns measuring 90cm were found by workers on the future Bródno metro.
The giant toothless creature was more closely related to mammals than dinosaurs and looked like a hippo with bent legs, a beak and two tusks.