Wooster’s Fossil of the Week: An asaphid trilobite from the Middle Ordovician of the Leningrad Region, Russia
Mark Wilson May 5th, 2013
This weathered trilobite is nothing like the gorgeous specimens of this genus you can buy at various rock shops around the world and on the web, but it has sentimental value to me. I collected it on an epic field trip in Russia in 2009. We hacked our way through the woods to an exposure of the Frizy Limestone (Volkhov Regional Stage, Darriwilian Stage, Middle Ordovician) where the local people had a side industry of quarrying out these trilobites for international trade. This specimen was the best I found, and it was probably abandoned by other collectors as too damaged. Still, it makes a nice reminder of my Russian experience and I keep it on a cabinet in my office. (By the way, I did not make a Cold War mistake in referring to the “Leningrad Region“. This oblast retains the old name of the city now known as St. Petersburg. Apparently the residents voted to keep it that way after the Soviet Union collapsed.)
This is the asaphid trilobite Asaphus lepidurus Nieszkowski, 1859. This group is known for having fantastic eyes, some on long stalks and others with calcareous “eyeshades” above them. This species has more conventional eyes, but they’re still cool.
A. lepidurus studies us with a cold, dead eye. From this perspective the facial suture is visible as the curved, raised line running from the near eye to the periphery of the cephalon (head). This is a line of weakness the trilobite used to split its exoskeleton for molting (ecdysis). These sutures often have diagnostic value for distinguishing trilobites, especially at the species level.
A. lepidurus was first described and named by Jan Nieszkowski (1833-1866), a Polish paleontologist (and naturalist and medical doctor). He was born in Lublin, Poland, son of an army captain. He studied at the University of Dorpat (now the University of Tartu in Estonia) and soon became an avid and productive paleontologist. He then participated in the January Uprising of Poles against the occupying Russians in 1863. He was captured and exiled to the Russian city of Orenburg, where he died at a young age of typhus.
This little trilobite brings back memories of my Russian adventure, and it is also a reminder that science is never done in a political vacuum. Here’s to the Polish patriot and scientist Dr. Jan Nieszkowski.
Dronov, A., Tolmacheva, T., Raevskaya, E., and Nestell, M. 2005. Cambrian and Ordovician of St. Petersburg region. 6th Baltic Stratigraphical Conference, IGCP 503 Meeting; St. Petersburg, Russia: St. Petersburg State University.
Ivantsov, A.Y. 2003. Ordovician trilobites of the Subfamily Asaphinae of the Ladoga Glint. Paleontological Journal 37, supplement 3: S229-S337.
Nieszkowski, J. 1859. Zusätze zur Monographie der Trilobiten der Ostseeprovinzen, nebst der Beschreibung einiger neuen obersilurischen Crustaceen. Archiv für die Naturkunde Liv-, Ehst-, und Kurland, Serie 1: 345-384.