Wednesday, December 23, 2009

Fossil find reveals whales as suckers

BRIDIE SMITH
December 23, 2009

A WHALE fossil found near Torquay more than 70 years ago has provided scientists with clues about how the mammals evolved, backing up the theories of naturalist Charles Darwin.

Museum Victoria palaeobiologist Erich Fitzgerald spent five years studying the fossil of a primitive toothed whale known as a Mammalodon colliveri and found, as Darwin had suggested, that some whales evolved as suction feeders.

Dr Fitzgerald said the findings showed that south-east Australia was ''a cradle of evolution'' for a variety of unusual, tiny baleen whales.

A specialist in the evolution of marine mammals, Dr Fitzgerald's research on the 25 million-year-old fossil is published in the latest Zoological Journal of the Linnean Society.

The Mammalodon colliveri, a relatively small whale at just three metres long, was unique to south-east Australia, with fossils only found in Victoria.

The fossilised skull and lower jaw of the whale, found in 1932 by local collectors, is just 45 centimetres long and has unusual features, including a short, blunt snout.

Large holes in the upper and lower jaws indicate the mammal - a close cousin of the 30-metre-long blue whale, the largest animal to inhabit the planet - had huge blood and nerve supply to the lips and facial muscles.

''This is unusual and no other baleen whale has this … and it tells us that the Mammalodon was feeding in a really unusual way. It suggests that it was a bottom-feeding mud-sucker,'' Dr Fitzgerald said. He said the whale probably used its tongue and snout to suck small prey up from sand and mud on the sea floor.

The fossil goes on public display for the first time at Museum Victoria until March. Since it was found in the 1930s, it was stored at Melbourne University's geology department before being transferred to Museum Victoria in the 1980s.

See video at: http://www.theage.com.au/national/fossil-find-reveals-whales-as-suckers-20091222-lbql.html

(Submitted by Peter Darben)

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