Rare Acanthoparypha gibba Russian trilobite

Acanthoparypha gibba, previously called Nieszkowskia tumidus gibbus, is among the very rarest of the trilobites from the Ordovician strata of the Wolchow River region near Saint Petersburg, Russia. While is has resemblance to the spiny trilobites of Order Lichida of the region, it is actually a Phacopid, and thus testament that the evolutionary twists and turns of a great Ordovician shallow sea elicited exotic forms across most trilobite families of the time, particularly of marine environments were recovering from the Cambrian-Ordovician extinction event. after which Order Phacopida first appears in the fossil record.