EXCAVATIONS IN THE PETRIFIED FOREST

The standing trunk of a pertified tree with a height of 7.02 m and a perimeter of 8.58 m. This is the largest known petrified trunk up to today, not only on the island of Lesvos but almost certainly in Europe. This lower trunk preserved in excellent condition is one of the largest plant fossils in the world. According to Professor E.Velitzelos, the artefact pertains to the species Taxodioxylon gypsaceum.

Finds which have come to light following excavations conducted by the Museum of Natural History of the Petrified Forest of Lesvos have proven to be of considerable scientific value. It is expected that these finds, officially announced at an international conference this May, will stimulate lively interest within the scientific community and among the numerous visitors who come to the Petrified Forest each year to marvel this truly unique natural monument.

This year for the first time the Museum is carrying out excavations in the area of the Petrified Forest in cooperation with the Lesvos Directorate of Forests with funding provided by the Ministry of Culture. The purpose of this endeavour is to uncover parts of the Petrified Forest buried under large masses of volcanic rock and to collect data regarding the composition of the fossilised ecosystem. Finds are to be exhibited in their natural environment within the Petrified Forest Park as well as in the museum now under construction. Excavations are being conducted under the direction of Museum Director Dr N.Zouros in cooperation with Professor of Palaeobotany - Palaentology of the University of Athens, E.Velitzelos.

The principle excavation area is located within the Petrified Forest Park at «Bali Alonia», site of the largest concentration of petrified trees.

To date excavations have progressed considerably revealing a large number of fossilised plants of particular scientific importance. In the course of activities, five excavation pits were opened revealing the followings:

First excavation site

The standing trunk of a pertified tree with a height of 7.02 m and a perimeter of 8.58 m. This is the largest known petrified trunk up to today, not only on the island of Lesvos but almost certainly in Europe. This lower trunk preserved in excellent condition is one of the largest plant fossils in the world. According to Professor E.Velitzelos, the artefact pertains to the species Taxodioxylon gypsaceum.

Two standing petrified conifer trunks less than 2.0 m apart most probably pertaining to the Protopinaceae family. The heights of the trunks are 2.70 m and 2.22 m, having perimeters of 2.90 m and 2.26 m respectively. The external structure and internal characteristics of the wood are excellently preserved with the concentric annual rings evident in both cases. In all likehood, these trunks pertain to the new coniferous species Pinoxylon paradoxum SUSS & VELITZELOS, first found in Lesvos and abundant throughout the broader region of the Petrified Forest of Lesvos.

Second excavation site

Two standing petrified conifer trunks less than 2.0 m apart most probably pertaining to the Protopinaceae family. The heights of the trunks are 2.70 m and 2.22 m, having perimeters of 2.90 m and 2.26 m respectively. The external structure and internal characteristics of the wood are excellently preserved with the concentric annual rings evident in both cases. In all likehood, these trunks pertain to the new coniferous species Pinoxylon paradoxum SUSS & VELITZELOS, first found in Lesvos and abundant throughout the broader region of the Petrified Forest of Lesvos.

Apart from the above mentioned, excavations also brought to light a fallen trunk probably of the species Taxodioxylon gypsaceum. Excavation of this particular trunk is still in progress.

Third excavation site

A standing petrified tree trunk, the upper section of which was revealed as a result of the natural erosion of volcanic rock. The tree’s root system has been uncovered in very good condition. The height of the artefact is 2.15 m and perimeter 2.18m. Besides this is a falen petrified trunk, a large portion of which was also uncovered as a result of the natural erosion of volcanic rock. The restored trunk using the existing fragments and pieces measures 4m in length. Excavation of the particular trunk is still in progress.

Forth excavation site

A standing petrified trunk with impressive shades of purple, clear annual rings and excellently preserved morphological characteristics of the wood’s structure. According to speculations this tree pertains to the protopinaceae family, more specifically of the species Pinoxylon paradoxum SUSS & VELITZELOS. The height of the trunk is 2.05m and its perimeter 2.56m.

Fifth excavation site

A standing petrified trunk twisted in a characteristic fashion most probably because of the pressure exerted by the volcanic material that covered the flora and finally led to petrification. This trunk is of a diameter of 50 cm and height of 1.2 m. Excavation has not yet been completed.

In the course of excavations, parts of plants were uncovered (fruit, leaves, branches, roots) which have remained well preserved until today, protected by the volcanic material in which they are embedded. Nonetheless, exposure to the elements of the erosion, the danger of theft and destruction  pose a true threat for these fragile artefacts. Finds of this nature are to be exhibited in the Museum of Natural history of the Petrified Forest.

Initial Conclusions

The importance of the finds is based on the fact that they reveal with great certainty that the area of excavation is located at the highest point of mixed coniferous forest. The majority of trees in the forest are of the species Taxodioxylon gypsaceum (GOPPERT) KRAUSEL. This species is a ancestor of the present day species Sequioa semprevirens. Contemporain trees of these species, classified as members of the Protopinaceae family, reach a height of 120-130m. The majority pertains to the new coniferous species Pinoxylon paradoxum SUSS & VELITZELOS first found on Lesvos and ancestor of the present day pine-tre. The olotipos of the species exists within the Petrified Forest Park.

Representatives of poplar, bay, cinnamon, plane, oak, beech, palm, sklithro, maple and cypress-tree species have also been found in the Petrified Forest.

The composition of the petrified flora demonstrates that 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.

The abundance of preserved standing trunks with their root systems intact and in a stage of full development, attests to the fact that the trees were petrified and are still located in their original position. In other words, this is an indigenous petrified forest. Aside from the petrified trunks, fossilised roots, fruit, leaves, seeds etc. are preserved in excellent condition, embedded in and protected by volcanic rock.

The geological history of the Aegean basin of the last 20 million years is imprinted upon the petrified forest. This provides us with unique information not only regarding the flora but ecological conditions, the climate and its fluctuations, volcanic activity and the tectonic movement which resultd in the geological structure and formation of the area.

Our medium term aims are to conduct systematic excavations to uncover the numerous petrified trunks that are nowdays covered by volcanic rock. There are indications that a particularly large number of petrified trunks are from coniferous trees of the species Pinoxylon paradoxum, Taxodioxylon gypsaceum and Cunnihamia meiocenica which made up the subtropical forest which was developed in the Aegean region 20 million years ago. At lower relief points, the coniferous tree forest is mixed with the deciduous forest. An ecosystem comparable to that which existed in the Petrified Forest, the subject of research conducted under the auspices of the Museum, is that of coniferous forests found today in North America.

Our medium term aims are to conduct systematic excavations to uncover the numerous petrified trunks that are nowdays covered by volcanic rock.

The excavation finds provide us with unique information not only regarding the flora but ecological conditions such as   tectonic movements which resultd in the geological structure and formation of the area (see twisted laying tree trunk).