The tree disappeared from the Americas millions of years ago

Jan 13, 2014 22:11 GMT  ·  By
About 50 million years ago, Australia, Antarctica and South America were linked by land
   About 50 million years ago, Australia, Antarctica and South America were linked by land

A group of scientists at the Pennsylvania State University (Penn State), led by professor of geosciences Peter Wilf, announces the discovery of tremendously-important fossils in South America. This time, the remains did not belong to animals, but to a species of giant coniferous evergreen tree. 

Botanists say that this discovery demonstrates a theory proposed long ago, which holds that Australia and South America were once in contact with each other. The tree in question is called Kauri in Australia and Dammar in Asia. It has been extinct in South America for millions of years.

The international team of paleobotanists behind the new research were able to identify fossilized specimens of Agathis (the scientific name for Kauri), in the fields of Patagonia. The group estimated that these trees existed in South America roughly 52 million years ago, during a time when Earth looked a lot more different than it does today.

Wilf argues that Agathis once extended from Australia, through Antarctica, and all the way to Patagonia, when the three continents were glued to each other. Confirming the existence of this tree species in Antarctica is very troublesome, since any forests on the Southern Continent were engulfed by miles-thick ices some 30 million years ago.

At this point, Agathis trees can be found from Sumatra, in Indonesia, all the way to New Zealand, southeast of Australia. Most specimens grow to be 40 to 45.5 meters (130 to 150 feet) tall, though they can reach 60 meters (200 feet) in some cases. Its resin was once used for linoleum and varnishes.

“Agathis was a dominant, keystone element of the Patagonian Eocene floras, alongside numerous other plant taxa that still associate with it in Australasia and Southeast Asia,” the research team wrote in the January issue of the esteemed American Journal of Botany.

“There is a fossil record of Agathis in Australia and New Zealand, where it still lives. However, Agathis fossils have never been found anywhere else until now, and they have never been as complete as these,” Wilf explains. Tree specimens ranging from 52.2 million years old to 47.7 million years old were found at two distinct locations in Patagonia.

“Agathis probably existed in all three areas, Australia, Antarctica and South America, at that time. Climate change in Antarctica – the cold and ice – killed them there, and a change to seasonal dryness in southern South America put an end to them in Patagonia,” the researcher concludes.