10/15/2026
October 15 marks National Fossil Day, an occasion dedicated to highlighting the scientific and educational importance of fossils. Pictured here is a remarkable fossil piece of red shale with a clear shell attached. This fossil was gifted to Governor Samuel W. Pennypacker by R.P. Sharples, the editor of the Phoenixville Star in the 1880s.
This fossil, along with others, was unearthed during the construction of a railroad tunnel in Phoenixville, Pennsylvania. The fossils found date back to the Late Triassic period, approximately 200 to 230 million years ago. As the Black Rock and Fairview Tunnels were carved through the Lockatong Formation, a Late Triassic geological unit, they revealed a region that was once a vast system of rift valley lakes and tropical mudflats.
The formation's mudstone, siltstone, shale, sandstone, carbonate rock, and hard massive argillite, provided an ideal environment for preserving various prehistoric life. These fossils offer invaluable insights into the ancient ecosystems that once inhabited the Phoenixville area.