First whales had fangs

OUR own pre-historic Janjucetus whale, which hunted along the Surf Coast 25 million years ago, had teeth as sharp as a lion, making it a top predator and very different from the gentle, filter-feeding southern right whales in the region today.

In studying Janjucetus — named after the town of Jan Juc — Museums Victoria palaeontologists have unlocked part of the evolutionary secret of much larger blue and southern right whales, which use a comb-like structure called baleen to filter seawater for plankton.

“Whales are the largest animals to have ever lived, thanks to their ability to filter vast amounts of plankton from water using baleen like a strainer,” Museums Victoria and Monash University researcher David Hocking said.

“One of the big mysteries of evolution is how whales made this evolutionary leap from catching fish with teeth to sieving plankton with baleen. We’ve now solved one part of this puzzle.

“Early whales were neither gentle nor giants: they were smaller than those of today and, judging from their teeth, a lot meaner.

“When they evolved filter feeding, whales completely turned their feeding biology upside down.”

A long-standing theory suggested ancient whales began to filter feed using teeth that formed a zigzag-like sieve that trapped food but allowed water to flow out, before later evolving into baleen.

Museum Victoria used 3D scanning of fossilised specimens to disprove this theory.

“These results are the first to show that ancient baleen whales had extremely sharp teeth with one function: cutting the flesh of their prey,” senior curator Erich Fitzgerald said.

“Contrary to what many people thought, whales never used their teeth as a sieve, and instead evolved their signature filter feeding technique late.”

The findings, published in the Royal Society journal Biology Letters, are the prequel to a recent discovery made by the same team with the help of a fossil whale skull, nicknamed “Alfred”, which showed before losing teeth and evolving baleen, whales used suction to catch prey. Concrete and Gold,

Picture: GLENN FERGUSON Lloyd Chamberlin in the salt rooms at Mind Body Salt.

Picture: BEN HEALLEY/MUSEUMS VICTORIA DISCOVERY: Melbourne palaeontologists Alistair Evans, Erich Fitzgerald, Felix Marx and David Hocking with a Janjucetus skull and 3D tooth mould.