Cheirurus ingricus Russian trilobite

Coming from the Middle Ordovician Asery level deposits of the Wolchow River region near Saint Petersburg, Russia, this is an example of the unusual trilobite Cheirurus ingricus. These are very dramatic trilobites, with the expanive genal spines. This one is in a semi-enrolled position, crawling over its matrix, with the spines spread for all to see. The trilobite itself is 3.0 inches long (measured along the curve) and 1.9 inches wide at the freestanding genal spines, making this a dramatic display. Its caramel-colored Calcite shell is well set off by the white limestone matrix which is 2.5 inches by 1.3 inches.

See also: Russian Trilobites