Ancient Whale Was T-Rex of the Sea

Aug. 16, 2006 — Scientists in Australia have discovered a fossilized 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," Monash University graduate researcher Erich Fitzgerald said.

While baleens are large — with the blue whale reaching up to 98 feet — the prehistoric predator was a swift hunter just 11.5 feet long that fed on fish and small sharks, Fitzgerald 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," Fitzgerald 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 realized it was something new," Fitzgerald said.

Fitzgerald's findings will be published this month in the Royal Society journal, and 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.

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.