Taeniaster spinosus starfish from Pennsylvania

This is a piece of mudstone from the Martinsburg formation at Swatara Gap, PA with parts of a fossil starfish called Taeniaster spinosus.

Swatara Gap was a well known collecting site up until about ten years ago when the Pennsylvania Department of Transportation buried the site to prevent undercutting of I-81. The Martinsburg formation is dated to the late Ordovician (Katian stage or Tentonian to Edenian of N. America stages)