Here is a large plate of shale with two Flexicalymene retrorsa trilobites. This specimen is from the Ordovician of Ohio. The trilobites are very inflated and nicely articulated. Both of the trilobites have the free cheeks intact and tightly attached. The trilobites have thick, brown exoskeleton and contrast nicely with the gray matrix. This is a very nice specimen of Flexicalymene retrorsa from Ohio.