Friday , August 19 2022

The fossils of ancient tooth whales are found in Victoria


Thousands of "strange" toothed whales wandering the planet's oceans millions of years ago, but disappeared because of falling sea levels.

Victorian scientists used fossilized ear bones to help identify why the toothed paleen whales disappeared about 23 million years ago.

Hundreds of bones, described as the "fingerprints" of whales, were collected around the Torquay and Geelong areas of southwest Victoria.

"We wanted to get to the bottom of the question of what happened to the whales in this apparent dark age," said Victoria Museums palaeontology and curator Dr Erich Fitzgerald.

The research was published in a leading international palaeontology journal this week.

Few whale fossils and virtually no known fossil whales of paleen whales from the mass extinction period.

Before mass disappearance there were plenty of different whale species including "strange" varieties with teeth.

"Toothed paleen whales seem to have disappeared … early primitive paleen whales that were so ancient that they still had teeth," said Dr Fitzgerald.

He said the research suggested that the smaller types of toothed whales living in shallow coastal waters disappear in the "dark age" period.

"What happened to the small, hooked, coastal whales, small toothed ones … environmental change has a big part to play."

He explained that a global reduction in sea levels had resulted in the loss of coastal seas and the loss of habitat to the toothed whales.

The larger offshore whales managed to survive sea level changes but it took millions of years for these whales to repeat the coastal areas.

According to the research, environmental change had evolutionary consequences, says Dr Fitzgerald.

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