Wednesday, May 31, 2023

Ceraurus? Trilobite Fossil


A few weekends ago, I was able to attend a field trip to Napoleon, Indiana USA. While there, I found this partial trilobite fossil which might be a Ceraurus (Chierurus) niagarensis (Hall, 1870). It dates to the Silurian Period  (Telychian to Sheinwoodian stage) in age. The fossil I was looking for this trip was that of the trilobite Spathacalymene nasuta (Ulrich, 1879).

According to Dr. James Thomka, professor at SUNY Plattsburgh, it is "from the mudstone lithofacies of the Massie Formation (long known as the "upper Osgood shale"), which is renowned for its 'cystoid' fauna."