LESVOS PETRIFIED
FOREST (GREECE)
Taxodioxylon gypsaceum trunk measuring 4.30 m in height and 1.15 m diameter.
The petrified forest situated near Sigri on the western side of the Greek island of Lesvos is possibly the most extensive of the known petrified forests. It exists over an area of 150 kmē or more. Large, upright trunks complete with root systems are found, as well as trunks up to 22 m in length.
The sub-tropical forest is of Late Oligocene to Lower - Middle Miocene age (15-20 Ma), and was buried within volcanic ash during intense volcanic activity in the area. The first report on the petrified forest was in 1844. Since 1979, the Division of Historical Geology and Palaeontology of the Department of Geology at the University of Athens, has been conducting palaeobotanical research in the petrified forest of Lesvos.
The
Lesvos Petrified Forest is managed by the Natural History Museum of the Ministry
of Culture, Hellenic Republic. Natural
Monument status was decreed in 1985 and a museum was commenced in 1994.
The museum has hosted international symposia dealing with natural monuments,
geological heritage, geoparks, geotourism and environmental education.
This
standing trunk at left is of height of 7.02 m and perimeter of 8.58 m. It is the largest
known petrified trunk in the Petrified Forest on the island of Lesvos, and
possibly the largest of anywhere in Europe. Trunks like this are the
largest plant fossils in the world. The species of the large tree has been
identified as Taxodioxylon gypsaceum. The majority of trees in the forest
are believed to be T. gypsaceum. This species is regarded as an
ancestor of the present day species Sequioa semprevirens which grows on the west
coast of the USA (California, Oregon). The two smaller trees
at above right may be Pinoxylon paradoxum. The Petrified Forest of Lesvos
developed in a subtropical climate that abruptly changed to a warm continental
climate. The flora of the region was that characteristic one of subtropical
zones of Southeast Asia and America. 
Of the trees
preserved in fallen position which have so far
been encountered, the longest (above right)
is more than 20m in length.