Rare Cyrtometopus Russian Phacopid Trilobite
Order Phacopida, Suborder Cheirurina, Superfamily Cheiruroidea,
Time: Lower Ordovician, Kunda Horizon
Site: Wolchow River Region, Kunda Horizon, St.
Petersburg region, Wolchow river, Russia
Coming from the nearly half billion year old Middle Ordovician
Level deposits of the Wolchow River region near Saint Petersburg,
Russia, this is an example of a member of the Order Phacopida,
Cheiruridae of the genus Cyrtometopus. Its affinities with other
Cheirurids such as Nieszkowskia
are apparent, but there are substantial differences as well.
trilobite itself is 35 mm long (measured along the curve) and 25
mm wide at the dramatically backswept pygidial spines.
Notice the small Brachiopod to the left of the right genal