Four fossilized forests finally find a home
Sigri on Lesvos is the site of a rare stone garden. The trunks of fossilized trees have become a fine museum of natural history, as a result of efforts by Nikos Sifounakis, minister for the Aegean. An extensive network of museums on the sites of fossilized forests in Evia, Evros, Kastoria and Lesvos will soon open to the public. When these fossils were formed, the Greek landscape bore little resemblance to what it looks like today. The climate was subtropical, hot and humid, with an average annual temperature above 12 Celsius. Palms, cinnamon, cypresses and sequoia grew there, and among them wandered elephants 2.5 meters high with huge tusks and trunks. In the lakes swam fish related to modern species. Lesvos and Evros The Natural History Museum of Sigri on Lesvos was inaugurated a few weeks ago. Local residents recall the archaeologists who used to dig and search in the area in the 1970s, when there wasn’t even a proper road. Evangelos Velintzelos, now a professor of historical geology at the University of Athens, tried to convince the State to designate the fossil forest a protected area because it was being pillaged by people who quarried opals from it for use in jewelry-making or for private collections. Intensive, systematic excavation began at Sigri in 1997. More than 100 tree trunks were found and restored. We knew the location of many of them, says Nikos Zouros, director of the Lesvos Museum, but we decided not to excavate them until we found a safe way to exhibit and preserve the finds. The fossils not only had to be dug out, but they also had to tolerate the weather conditions outside. The geologists have to deal with major dilemmas whenever they expose an ancient tree trunk to the weather. Rainwater and winter ice corrode the fossils. Great variations in temperature turn the water which soaks the trunk into ice. When it expands it can break the stone. So the scientists also had to experiment with new conservation techniques. The material used now is a special resin which fills the gaps in the trunks and prevents rainwater from entering them. In addition, many of the exposed fossils are covered over in winter for protection. The most important find in the area is the mastodon found in September 1999 in the Antissa-Gavatha area. This animal lived on the slopes of the petrified forest, says Zouros. When it died it it was covered by lake sediment which encased its bones. The bones were cleaned with great care, an extremely time-consuming task, due to the hardness of the surrounding layer of limestone that had become pyrite. The vertebrate was analyzed by Georgios Koufos, professor of paleontology at the University of Thessaloniki, who says the creature was a forebear of today’s elephants which lived during the Early Miocene period, about 20 million years ago. It is an extremely rare find. The oldest petrified forest in Greece is in the Evros area. It stretches from Alexandroupolis to the Evros River, and many places in the region wanted to host the museum, which the State eventually decided to build in Alexandroupolis. The forest is 25 million years old and has some of the most abundant fossil flora in the world. We located the first oak species there, says Velintzelos, and four types of palms were recorded there, along with sequoias and cypresses. The area, which had a much warmer climate than the forest on Lesvos, experienced intense volcanic activity which gave rise to alternating marine and land ecosystems. This is why not only plant and tree fossils but also fossils of coral and large sea creatures, such as sharks, were found in this area. A 25-million-year-old herring fossil was also found there. From Kastoria to Kerasia It’s hard to believe that Kastoria was once home to mastodons, 25-meter-long sharks and to marine organisms that are now found only in tropical climates. Yet 20 million years ago the flora and fauna of the area were very different from those of today. The construction of the museum in Kastoria has been completed and the equipment has been delivered. Only the final preparations on the museum remain to be done. Until recently, the petrified forest of Kerasia on Evia was at the mercy of the elements but now the architectural study of the museum that is to house the fossils has been completed. As Velintzelos explains, most of the tree trunks found in this area were still standing and seem to have been covered by volcanic material. Vegora basin Sediment in the lignite-bearing basin of Vegora in western Macedonia contains rare plant fossils, many of which are in a perfect state of preservation. In 1970, when Velintzelos was still teaching at Saarbrucken University in Germany, he began to excavate and evaluate the fossils. Among them were conifers, sequoias, pines, cedars, palms, planes, walnut and hazelnut trees, as well as other subtropical plants which scientists say bear a strong resemblance to forests today in the Caucasus, North America and Southeast Asia. Unfortunately, says Velintzelos, plant fossils which are indis putable witnesses of plant evolution are being eroded by weather conditions after lignite quarrying. The Vegora area is the only fossil site which has yet to be surveyed and set up as a museum.