The longest worldwide petrified tree has been discovered in the Bantak Petrified Forest Park, measuring 2 metres in diameter and over 72 metres long. Bantak Petrified Forest Park is located in Tak Province, in the west of northern Thailand.
Petrification is the result of a tree having completely transitioned to stone with all the organic materials replaced with minerals while retaining the original structure of the plant material A large petrified log, partially exposed for about 1 metre, was found by a villager in a forest at Ban Tak District, Tak Province, in October 2003.
The discovery of the petrified wood was reported to the National Park, Wildlife and Plant Conservation Department,
under the administration of the Ministry of Natural Resources and Environment. An officer from the department subsequently came to examine the petrified log and survey the surrounding area. The petrified log was further excavated and the trunk was exposed to a length of 21 metres without reaching the upper end.
Many additional pieces of petrified wood were found scattered in the surrounding area covering 35 square kilometres or more. Some pieces were found on the soil surface and some only partly exposed with problems being experienced with people illegally removing sections to be sold as souvenirs. These fossil trees are very important in terms of scientific value. They help to understand the diversity of ancient trees, paleobiogeography of plants, the climate and environment of the past, including geological changes through time.