Monash University PhD student Erich Fitzgerald inspects the skull of a 25-million-year old fossil from southeast Australia, identifying a new family of small, highly predatory, toothed baleen whales.
Credit: William West/AFP
SYDNEY, 17 August 2006: Scientists in Australia have discovered a fossilised ancient relative of the blue whale with a fearsome razor-toothed appearance that has seen it dubbed "the T-rex of the oceans".
The fossil is the latest in a list of ancient creatures including sabre-toothed kangaroos, horned "devil wallabies" and the unlikely-sounding "demon duck of doom" that are reshaping views of Australia's prehistoric past.
The 25-million-year-old whale fossil has forced scientists to rethink the evolution of baleen whales, the placid giants which feed by using fine hair-like fibres in their mouths to filter plankton from the sea.
"The fossil proves the baleen whale, including toothless filter-feeders like the blue whale, often thought of as gentle giants of the sea, were not always so giant or gentle," said Monash University graduate researcher Erich Fitzgerald.
While baleens are large, with the blue whale reaching up to 30 metres, the prehistoric predator was a swift hunter-killer only 3.5 metres long that fed on fish and small sharks, Fitzgerald said.
He said it also had large eyes, like a modern great white, to compensate for its lack of sonar.
"[It was] Australia's very own T-rex of the oceans," he said.
The whale fossil was discovered in a limestone rock in the late 1990s by a teenage surfer at Jan Juc Beach in Victoria state.
Formally known as Janjucetus hunderi, the fossil lay unstudied for years until Fitzgerald spotted it on the desk of a PhD student.
"As soon as I saw it I realised it was something new," Fitzgerald said.
Fitzgerald's findings will be published this month in the Royal Society journal.
The fossil went on display Wednesday at the Melbourne Museum in Victoria. Museum Victoria's head of science John Long will also this week present findings from expeditions into a cave in Australia's remote Nullarbor Plain that yielded a fossil treasure trove, including the only complete marsupial lion skeleton ever found.
"It was a once-in-a-lifetime fossil," Long said. "For the first time we could see the complete limbs and feet, revealing an opposable thumb with a huge retractable claw which was used to disembowel prey.
"It was like the velociraptor of the mammal world."
The marsupial lion became extinct about 50,000 years ago, along with the rest of Australia's so-called "mega-fauna", the giant versions of harmless modern Australian animals such as wombats, kangaroos and koala bears.
The Nullarbor caves contained some 60 mega-fauna skeletons, including 10 marsupial lions and a new special of marsupial nicknamed the "devil wallaby" because of the horn-like protrusions on its head.
"They probably protected its head when it was eating spiny plants," Long said.
The University of New South Wales last month said it had found fossilised remains of a flesh-eating, sabre-toothed kangaroo that lived in Queensland more than 10 million years ago.
It also unearthed evidence at the same site of a large carnivorous bird weighing up to 400 kilograms dubbed the "demon duck of doom".
Scientists had long wondered whether the appearance of humans in Australia 45,000 years ago led to the extinction of the continent's mega-fauna.
However, this month a team from the University of Melbourne and La Trobe University released a study arguing that climate change killed the giant beasts up to 10,000 years before man arrived.
