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Today's gentle giant whales were once fearsome predators with sharp teeth

30 Août 2017

Fossilized ancient whale skull.

Museum of Victoria scientists developed their study after creating a 3D model of a prehistoric tooth which was dug out of the rocks near Torquay on Victoria's southern coastline in 2016.

Their growth spurt, which has seen blue whales balloon to up to 30m in legnth, was mainly driven by climate changes and a massive increase in the amount of plankton in the ocean.

All living whales are descended from terrestrial mammals, but how these aquatic creatures evolved into giant filter-feeders remains a biological mystery.

"Our findings provide crucial new insights into how the biggest animals ever evolved their most important trait: filter feeding", Evans said.

'These teeth are adapted for one thing only and that is cutting and slicing flesh, and in fact they are almost as sharp as the teeth of today's top predators like lions, cheetahs, wolves and dingos, ' he told AAP. "Filter feeding is the defining trait of modern whales - there are few ways in which this unique strategy could have evolved from tooth-bearing, predatory ancestors, and our study firmly rules out one of them".

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As she battles for re-election, Mrs Merkel has been subjected to ridicule and protest over her laissez-faire stance on migration. Merkel lost popular support past year over worries about how Germany could absorb an influx of over 1 million migrants.

But until now, researchers weren't exactly sure how ancient whales put their teeth to use. As Evans explained, the size, orientation, and sharpness of teeth can tell us much about what an animal eats.

"Predators that kill and chew their prey need sharp teeth with cutting blades", Dr Evans said.

Ancient whales had extremely sharp predator teeth similar to lions, Australian scientists said Wednesday in a discovery they believe debunks theories the mammals used their teeth to filter feed like today's gentle giants.

The sieve trapped food in the mouth and also allowed water to flow between the teeth.

Can't get here from there: New research suggests baleen filters emerged independently from ancient "raptorial" teeth. The "raptorial" composition of this ancient teeth (i.e. teeth used to grab and chomp-up large prey) highly preclude the possibility of these features evolving into the keratinous, comb-like filtering structure that now grows in the upper jaw of modern baleen whales, say the researchers.

Today's gentle giant whales were once fearsome predators with sharp teeth