Newspaper Article 1999 – Hunt for lizard’s killer

Hunt for lizards’ killer

By Sue Thomas

Scientists were to don their coats, boots and microscopes today and began searching for fossils in the Mangahouanga Stream to support a dinosaur extinction theory.

The scientists from Denmark, the United States and New Zealand made the three-hour drive into the rugged area inland from Kotemaori yesterday and were due to begin their investigations today.

Their brief is to find out what killed the dinosaurs 65-million years ago.

By examining a selection of sites, the researchers aim to compare levels of extinction and disruption to ecosystems from on land to the ocean deep.

Many scientists believe a catastrophic event, such as the earth’s collision with a giant meteorite 65-million years ago, triggered a sequence of events that led to the demise of the dinosaurs.

Geologists and palaeontologists are divided on the theory because although they accept the evidence for a meteorite impact, they are not convinced it caused the extinctions.

The theory does not explain why some groups of animals went extinct and others did not or why some extinctions such as the dinosaurs, appear to have occurred gradually over the last few million years of the Cretaceous period.

The Hawke’s Bay site is of particular interest to the scientists because it is the only New Zealand site associated with fossil remains of dinosaurs.

The expedition, is being led by palaeontologist Chris Hollis from the Institute of Geological and Nuclear Sciences.

He said New Zealand research had an important role to play in understanding the causes of the dinosaur extinctions.

“Because the country is far removed from the proposed meteorite impact site in Mexico, it is possible to determine whether the catastrophe was truly global in nature,” Dr Hollis said.

Sites between Otago and Hawke’s Bay provide a cross-section through a continental margin.

“New Zealand is an ideal location to resolve the dinosaur debate.” Mr Hollis said.

“Although several thousand kilometres from the Yucatan Peninsula, Mexico, where scientists believe the meteorite impact site to be, debris from the impact appears to be abundant in several sites in Marlborough at the northern tip of the South Island.

“We have the opportunity to compare changes in plants and animals across an environmental profile from terrestrial swamp to continental shelf to deep ocean.

‘In this way we can find out if the changes really were instantaneous, as we’d expect from a sudden global catastrophe or progressive – perhaps affecting the ocean environments first and late affecting the terrestrial realm as we might expect from more gradual climate changes.”

The researchers also want to find out why some fossil studies suggest extinctions in New Zealand were less severe than in the equatorial and Northern Hemisphere areas.

The scientists will spend three days conducting research in the Mangahouanga Stream area.

It will be at least a year before the outcome of their findings is known.

Photo caption – Expedition leader Chris Hollis, with Haumoana’s dinosaur lady Joan Wiffen, and a dinosaur vertebrae she found, in front of a dryosaurus model at the Hawke’s Bay Museum yesterday.