Iconic Australasian Trees Found as Fossils in South America

Sophie Antonioli

Mr. Mathieu

Period 2

14 January 2014

Author: unknown

Published: January 9, 2014

Link: http://www.sciencedaily.com/releases/2014/01/140109132650.htm

Summary:

Scientist have recently discovered a tree fossil native to Australian in South America. The tree is known as Dammar in Australia and Kauri in Asia but does not have a name in South America due to the fact that it was not grown there unless planted. This specific tree is 52 million years old and the most intact fossilized one that they have found anywhere. The scientists are predicting that these trees grew in Patagonia when the supercontinent Gondwana was formed. Gondwana was made of Australia, South America, and Antarctica. It is also thought that the Agathis (another name for the tree) must have also grown on Antarctica because it was not all ice when Gondwana was composed. However, the trees much have died because of the extreme temperatures that later undertook Antarctica. So, the Agathis tree moved away from the cold south and towards northern Australia and spread to Asia. In Patagonia, they died out due to the seasonal dryness. The inconsistancy of water availability made it hard for them to survive.

Connection:

In this unit, we learned about continental drift and adaptation. Continental drift plays a huge role in this discovery. We know that the tree was able to be on all three of these continents (South America, Australia and Asia) because the continents were once connected. Without this connection, if Gondwana was never formed, the Agathis tree would not be present in all these places because of geographic isolation. It is also important to notice that as Antarctica began to freeze, the trees were dying and natually migrated north, toward the equator where they could survive in the hot and wet environments.