Whale fossil could shed light on 'dark age'

Bruce McCulloch (right) and his son Murray found the skeleton on a beach near Oamaru in 2007....
Bruce McCulloch (right) and his son Murray found the skeleton on a beach near Oamaru in 2007. PHOTO: BRONWYN MCCULLOCH
A suspected 20 million-year-old fossilised whale, which for the past 12 years has been lying in an Oamaru backyard, could now help answer questions about a "dark age''.

Visiting PhD candidate Atzcalli Ehicatl Hernandez Cisneros, of the Instituto Politecnico Nacional...
Visiting PhD candidate Atzcalli Ehicatl Hernandez Cisneros, of the Instituto Politecnico Nacional in Baja California Sur, Mexico, who calls the collection of fossils at Bruce McCulloch's home a "candy store'', pulls a fossilised whale's ear bone from the pile in Oamaru. PHOTOS: HAMISH MACLEAN
Prof Ewan Fordyce, a paleontologist in the University of Otago geology department, said if the fossilised remains of the whale recovered from a nearby beach by the McCulloch family, of Oamaru, were in fact the bones of an animal from 20million to 23million years ago, it would also "quite likely'' represent a newly discovered species - but the work to confirm that had only just begun.

The so-called dark age was an "obvious gap'' in the fossil record of whales and dolphins through much of the world - and one of the hypotheses of the research he was now undertaking was that something crucial in the evolutionary process of modern cetaceans happened during that time.

"We are pretty sure that, especially with New Zealand fossils, we can resolve some of the issues of the dark age. We should be able to fill it in with species that have not been studied thoroughly - new specimens,'' Prof Fordyce said.

"We know when the dark age was, from 20 to 23 million years [ago], and we know that before the dark age there were various sorts of archaic whales and dolphins, which were ... ancestors in some modern lineages. We know that after the dark age the oceans were filled with diverse species of whales and dolphins - after this gap in the record.''

Former North Otago Museum director Bruce McCulloch, along with his family, especially his now 32-year-old son Murray, has fossicked on North Otago beaches for the past 25 years.

Assistant research fellow Marcus Richards shows the telltale "honeycomb'' in a fossilised whale...
Assistant research fellow Marcus Richards shows the telltale "honeycomb'' in a fossilised whale vertebra, which distinguishes the pre-historic bone from rock.
In November 2007, his son came across the fossilised whale skeleton on a beach south of Cape Wanbrow.

"We knew it was a whale - it was pretty obvious - and it was a huge number of vertebrae just stretched out along the sand. It's not going to be anything else but a whale - it's just too big,'' Bruce McCulloch said.

University of Otago department of geology paleontology lab technician Sophie White secures the 20...
University of Otago department of geology paleontology lab technician Sophie White secures the 20 million-year-old whale fossil for transport to Dunedin.
They knew it was a significant item, and called Prof Fordyce, but the next weekend when they returned to the beach pieces were already missing.

"They'd actually washed along the beach - they were actually weathering out; it wasn't lasting long - so we decided at that stage that in order to ... preserve it, basically, we had to pick it up then and there,'' he said.

It took the family about "four or five hours'' to recover the fossils, having hauled the last of them encased in sandstone off the beach just as Prof Fordyce arrived.

They agreed the family would store them at home at the time.

Mr McCulloch was "delighted'' when Prof Fordyce's research assistants arrived at his home late last month to transport the fossils back to the university.

Late last year, Prof Fordyce was granted $928,000 for a Marsden Fund project dubbed "Fossils of Zealandia elucidate a global 'dark age' in whale evolution''.

In a statement the university said preliminary fieldwork in the South Island had recovered unprepared fossils of the right age, and had identified other material yet to be collected.

Once the research is complete the fossilised whale will go to the North Otago Museum.

Forrester Gallery, North Otago Museum and Waitaki District Archives director Jane Macknight said staff were "tremendously excited'' to partner with the university on "new research into a largely complete whale fossil found along the coast in our district''.

The fossils would ultimately become a highlight of the museum's displays, she said.

hamish.maclean@odt.co.nz

 

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