Museums Victoria Researcher Ruairidh Duncan (L) and Palaeontologist Erich Fitzgerald with the partial fossil skull and teeth of Janjucetus dullardi in Melbourne / MUSEUMS VICTORIA / AFP

Australian scientists have discovered a razor-toothed whale that prowled the seas 26 million years ago, saying Wednesday the species was "deceptively cute" but a fearsome predator. 

Museums Victoria pieced together the species from an unusually well-preserved skull fossil found on Victoria's Surf Coast in 2019. 

Scientists discovered a "fast, sharp-toothed predator" that would have been about the size of a dolphin. 

"It's essentially a little whale with big eyes and a mouth full of sharp, slicing teeth," said researcher Ruairidh Duncan. 

"Imagine the shark-like version of a baleen whale -- small and deceptively cute, but definitely not harmless." 

The skull belonged to a group of prehistoric whales known as the mammalodontids, distant smaller relatives of today's filter-feeding whales. 

It is the fourth mammalodontid species ever discovered, Museums Victoria said. 

"This fossil opens a window into how ancient whales grew and changed, and how evolution shaped their bodies as they adapted to life in the sea," said palaeontologist Erich Fitzgerald, who co-authored the study. 

Victoria's Surf Coast lies on the Jan Juc Formation -- a geological feature dating to the Oligocene epoch between 23 and 30 million years ago. 

A string of rare fossils have been unearthed along the scenic stretch of beach, a renowned site for the study of early whale evolution. 

"This region was once a cradle for some of the most unusual whales in history, and we're only just beginning to uncover their stories," said Fitzgerald.

"We're entering a new phase of discovery.

"This region is rewriting the story of how whales came to rule the oceans, with some surprising plot twists."

The species was named Janjucetus dullardi, a nod to local Ross Dullard who stumbled across the skull while strolling the beach in 2019. 

It was described in the peer-reviewed Zoological Journal of the Linnean Society.

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