Remarkably beautiful, large, and tridimensionally preserved head ofBalteurypterus tetragonophtalmus on matrix.Eurypterids, also known as sea scorpions due to their pointed tails, originated in the Ordovician period. They were the dominant predators of the Upper Ordovician, Silurian, and Lower Devonian seas and reached their greatest species diversity during this time.This order's most impressive representatives could grow up to a length of 3 m, while Balteurypterus tetragonophtalmus only reached a few modest centimeters. The large group of eurypterids had a fin-like, powerful last pair of legs. They also had two respiratory systems, book gills and gill plates, and trace fossils show that they were quite capable of going ashore. Unfortunately, they didn't quite make the leap, for like their close relatives, the horseshoe crabs, they used their leg attachments for chewing, which is much more efficient underwater than on land.Fish were increasingly competing with them in the marine environment, causing the Eurypterids to retreat to river systems.Only a few varieties of what is believed to be the largest known arthropod of all time remained in the Permian period.Age: Silurian, Bagovitsa FormationLocality: Smotrych (left branch of Dniester River), near Kamianets-Podilskyi,Khmelnytskyi Oblast, UkraineHead size: 2.7 cmMatrix: approx. 3.5 x 3.5 cmDue to technical reasons, colors in product photos may differ from those of the original piece.

Age: Upper Silurian;Locality: Valley of Kosoř near Radotin, district Prague-West, Central Bohemian Region, Czech RepublicSize: approx. 5 x 5 x 1 cmColors in product photos may differ slightly from those of the original specimen due to technical reasons.

With potential for follow-up preparation.Age: Middle Silurian;Locality: Dudley, West Midlands, England, UKSize: approx. 5 x 4 x 2 cmColors in product photos may differ slightly from those of the original specimen for technical reasons.

Age: SilurianLocality: Gotland, SwedenSize: approx. 6 x 7 cm (coral 2x3 cm)Colors on photos may differ from the colors of the originals due to technical reasons.

Historical microscope slide with retiolid graptolite. Isolated and therefore very detailed.Rare piece!Age: Lower Silurian, Ludlow; Locality: Northern glacial till, Berlin-Spandau, Havelland/Berlin, GermanyDue to technical reasons, colors on photos may differ slightly from those of the original specimen.

Age: Silurian;Locality: Völkenreuth, Schwarzenbach an der Saale, Upper Franconia, Bavaria, GermanySize cardboard card: 9cm x 6,5cmColors on product photos may differ slightly from those of the original specimen due to technical reasons.

Age: Upper Silurian;Locality: Ronneburg, Main-Kinzig district, Hesse, GermanySize of cardboard card: approx. 8 x 12 cmColors in product photos may differ from those of the original specimen for technical reasons.

Age: SilurianLocality: Rostock, GermanySize:  Fossils 2,5 cm, Matrix 6,5 x 4 cmThe colours on the pictures may slightly differ from the original specimen.

Old collection piece.Age: Silurian;Locality: Kosov near Beroun, Bohemia, Czech RepublicSize: approx. 10 x 7 x 2 cmColors on photos may differ slightly from those of the original piece due to technical reasons.

Deformed lobolite (hollow, spherical stem section of Scyphocrinites), the “floating body” or floating apparatus of a crinoid.Age: Silurian;Locality: Karlštejn, Beroun district, Středočeský kra (Central Bohemian Region), Czech RepublicSize: approx. 8 x 7 x 3 cmColors on product photos may differ slightly from those of the original specimen due to technical reasons.

Two cephala and several thorax segments of Balteurypterus tetragonophtalmus.Eurypterids, also known as sea scorpions because of their pointed tails, evolved in the Ordovician. They were the dominant predators of the Upper Ordovician, Silurian and Lower Devonian seas and attained their maximum species diversity at that time.The most impressive representatives of this order could grow up to 3 m long, while Balteurypterus tetragonophtalmus only reached a few modest centimetres. The large group of eurypterids possessed a fin-like, powerful last pair of legs. They had two respiratory systems - book gills and gill plates - and trace fossils show that they were quite capable of walking on land. Unfortunately, they didn't quite make the leap, because like their close relatives, the horseshoe crabs, they used the tips of their legs to chew, which is much more efficient underwater than on land. Fish also increasingly competed with them in the sea, so that they retreated to the river systems. By the Permian, there were only a few species of these presumably largest known arthropods of all time. Age: Silurian, Bagovitsa Fm;Locality: Smotrych (left tributary of the Dniester), near Kamjanez-Podilskyj, Khmelnytskyi oblast, UkraineSize head: 1 x 1.3 cmSize matrix: approx. 5 x 7 x 1 cmColors on product photos may differ from those of the original specimen for technical reasons.

Historical microscope slide with retiolid graptolite.Isolated, so the structures are perfectly visible. A unique piece!Age: Upper Silurian, Ludlow; Locality: Northern glacial till, Berlin-Spandau, Havelland/Berlin, GermanyDue to technical reasons, colors on photos may differ slightly from those of the original specimen.