More than 20 million years ago, the massive lake in what is now the northwestern part of the island of Lesvos and the surrounding area, with its subtropical climate, was covered by layers of lava and became petrified. Today's visitors to the area of Sigri, but also Antissa and Eressos, enjoy a tranquil natural environment and the singular geopark of western Lesvos with its unique petrified trees.
The area's natural history is also the natural history of the planet.
Visitors to the Petrified Forest have justifiably been wondering about the apparent lack of animal life or, rather, fossils. The answer to their questions came a few years ago when excavations by scientists from the Sigri Petrified Forest Museum of Natural History brought to light, in the region of Gavathas, Antissa, the first indications of the existence of a large mammal. The first find, a fossilised lower jaw of a prehistoric form of a trunked animal, a proboscidean, was later identified by researchers as a representative of the Bavarian prodeinothere (species Prodeinotherium bavaricum). Although similar to today's elephants, the prodeinothere had downward curving tusks located in the lower jawbone. It is one of the lowest fossils of a vertebrate animal found in Greece to date and comes from one of the first trunked animals that migrated from Africa to Europe.
And then...nothing. At least up until a few days ago, at the 9th congress of the European Association of Vertebrate Paleontologists (EAVP) organised by the Crete Museum of Natural History in Heraklion, where geologist/paleontologist Katerina Vassiliadou, researcher at the Sigri Museum of Natural History, unveiled an incredible world of inhabitants that once lived among the fossilized trees in the Petrified Forest of Lesvos: snails, lake fish, reptiles and even prehistoric crocodiles, as well as small mammals, living creatures that walked the earth in this small part of the world millions of years before the advent of man.
The conclusions of the Lesvos Museum of Natural History's recent research activities in the Antissa area and discovery of a small layer of lake sediment rich in fossils of small animals were presented at the 9th EAVP annual meeting in Heraklion, Crete.
Vassiliadou told ANA-MPA that the presentation included a small introduction on the Petrified Forest and its plant fossils, as well as the prodeinothere fossil from Gavathas. Then followed a presentation of photographs from the recent samples taken of sediment created in the large lake that covered northwestern Lesvos from the era of the sub-tropical forest that later became fossilised (petrified).
After a time-consuming and meticulous process of cleaning and sifting, the miniscule grains of sediment were inspection under a stereoscopic microscope, researchers found fossils of snails, teeth, otoliths, osteic remains of fins and vertebrae of lake fish, portions of the chewing apparatus of small reptiles, crocodile teeth and teeth and bones of small mammals.
Examination and comparison of the finds conducted in Greek institutions and abroad showed that the fossilised lake snails were air-breathing (type of lung and lack of gills) aquatic gasteropod crustaceans of the Planorbidae and Lymnaeidae families that lived in the large lake that covered the area.
The pharyngeal teeth, otoliths and other fish remains were from small lake fish of the Cyprinidae family, the precursors of today's freshwater carps and barbs.
The crocodile teeth belong to a small alligator of the genus Diplocynodon, which grew to up to two meters in length and had bony armor scutes covering its neck, back, belly and tail, similar to today's Caiman alligator found in Central and South America.
The teeth of small mammals found belong to various families, while teeth were also found from three families of small insectivore families, namely Erinaceidae (hedgehogs), Talpidae (moles) and Soricidae (shrews).
Other fauna fossils are from the Muridae family of rodents from two genuses, Eumyarion and Democricetodon, both of which are extinct today.
Another rodent fossil is that of the Glirulus diremptus (kind of dormouse that is now extinct).
The systematic search for animal fossils, especially small mammals, in the Antissa area began in 2005.