Reptiles fossil helps rules out ancient flood in New Zealand

January 21st, 2009 - 12:37 pm ICT by ANI  

London, Jan 21 (ANI): The discovery of the fossil of a reptile on New Zealands South Island has helped to rebuff the theory that an ancient flood had submerged the countrys islands, just like the fabled Atlantis.

According to a report in New Scientist, Marc Jones of University College London, UK, and colleagues found the portions of fossilized reptile jaw on New Zealands South Island.

The wear patterns of the teeth suggest its owner had two parallel rows of upper teeth, and a single row of lower teeth that slotted in between.

The only reptile known to have this type of jaw is the endangered tuatara and its ancestors.

With its spiny crest and unique jaw, the lizard-like tuatara is remarkable even among New Zealands extraordinary wildlife.

But what is most exciting about the fossil that Jones found is its age.

It dates to just 3 million years after a time when some researchers have suggested the land mass that forms New Zealand sank beneath the waves.

After Zealandia New Zealands precursor broke off from Antarctica, it drifted northwards and shrank, due to a combination of tectonic movements and rising sea-levels.

Marine sediments that now lie above sea level provide evidence of this, but just how small the land area got is open to debate.

A group of researchers in New Zealand suggested that the absence of fossils between 25 and 22 million years ago means the islands completely disappeared, and then later re-emerged.

If this were the case, the ancestral tuatara discovered by Jones and colleagues, and all of New Zealands biodiversity, could only have arrived after the land drowned.

To do this, the ancient reptile would have had to cross vast oceans in a few million years.

According to the research team, this is an unlikely feat for an animal that is a poor swimmer and would have rapidly dehydrated in salt water.

Its not just the tuatara fossil that suggests New Zealand did not fully drown.

There is a lot of diversity in this fossil deposit, said Jones. There are about 24 species of birds, a lot of plants, insects, and freshwater fish. Four million years is a long time, but that still leaves a lot of explaining, he added.

Jones believes Zealandia sank, but did not disappear, allowing a certain number of species to survive and then repopulate as the continental crust re-emerged.

Even if it was reduced to 1 percent of current-day land area, there would still be quite a lot of land there, said Jones. Its quite possible there could have been an archipelago of islands and these can support a huge amount of life, he added. (ANI)

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