Visiting Russian scientists delve into permian era - 04/03/2014

Russian scientists have come to New Zealand to examine our fossilised bivalves in a bid to better understand conditions on Earth 260 million years ago.

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Two scientists from the Far East Branch of the Russian Academy of Sciences based in Magadan spent the past week in Wellington and Nelson collecting a large amount of information on fossil bivalves dating from about 270 million years ago – the late Permian Period.

New Zealand has arguably the best collection of these ancient bivalves in the Southern Hemisphere.

In terms of ecology and biodiversity, bivalve molluscs (clams and mussels) rose to prominence as a hugely successful group of marine organisms in the Permian era. There are Permian limestone formations in Nelson and Southland that are up to 500 metres thick, and are comprised almost exclusively of the shell remains of mussels collectively known as ‘Atomodesma’. In northern Russia, there are similar Permian limestones.

Dr Alexander Biakov and Igor Vedernikov wanted to compare the New Zealand fossils with their own extensive fossil collections in Russia.

“What’s amazing is that we have many genera in common with Russia, which underlines the fact that they were a dominant bipolar group of clams in the Permian era,” said Hamish Campbell, a senior palaeontologist at GNS Science and the host for the visitors.

The Russian pair spent three days poring over GNS Science’s National Fossil Collection in Lower Hutt, and three days exploring rock formations exposed in the Maitai and Roding River valleys near Nelson, where some of New Zealand’s best Permian fossils can be found.

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Their aim was to examine and collect representative New Zealand Permian rocks and fossils to take back to Russia for comparative research.

Dr Campbell said the pair had been aware of New Zealand’s Permian marine e fossil collections for at least three decades and were delighted to finally see them first-hand.

Distinctive Permian bivalves, including ‘Atomodesma’, became extinct 252 million years ago in an event called the Permian-Triassic extinction event. It is the Earth’s most severe extinction event with about 96% of marine species disappearing and about 70% of land animals.

The cause of this mass extinction event remains uncertain. Scientists have been exploring the possibility of a terrestrial cause (super-plume volcanism), but the available evidence is unconvincing. Increasingly, an extra-terrestrial cause seems more probable, but available evidence strongly suggests that it was not a meteorite. A comet impact is a possibility, but is very difficult to establish in terms of hard evidence.

Ongoing collaboration between New Zealand and Russian scientists may help resolve this intriguing question: did a comet cause the Permian-Triassic mass extinction?