Ancient ape fossil links earliest man to Thailand

Found in a Krabi coal mine, the fossil is even older than one formerly believed to be the ancestor of all primates - aged 32 million years and found in Africa.

Mineral Resources Department's director-general Adisak Thongkhaimuk chose the department's 118th anniversary yesterday to announce the discovery of the fossil's lower right-side jaw with teeth and a complete upper jaw attached to an eye socket. He hailed it as the world's oldest anthropoidia fossil and in the best condition.

Crediting the department's experts, Adisak said the Siamopithecus eocaenus fossil find had been published in the Anatomical Record in November 2009.

A previous jaw piece with inferior condition had been discovered in 1995 and published the following year in the magazine Nature. It described the new species of anthropoidia's ancestor as 7kg gibbon-sized and of the Amphipithecidae family, he said.

In 1996, department geologist Sasithorn Khansupa found more fossil pieces compressed between the mine's coal layers, but they were difficult to excavate without damage. Scanning by a micro CT scan and a 3D computer programme produced a full visual.

Geologist Dr Yaowalak Chaimanee said the finds confirmed the Siamese ape was a highly evolved ancestor of anthropoidia primates, whose face was short with eye sockets placed on the front and close to one another like a gibbon.

She said this ancestor hunted at daytime and lived on hard food. The discovery proved that anthropoidia primates originated and evolved in Asia, Yaowalak said. In Thailand they could be found at Krabi's Neu Khlong Coal Mine only. This contradicted previous theories the anthropoidia primates' ancestors and apes originated in Africa, following the discovery of 32-million-year old fossils there.

The Thai study was a collaboration of the department, France's Poitiers University, French Synchrotron Research Facility, and Switzerland's University of Zurich, with the Provincial Electricity Authority of Thailand's permission to survey the site.

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