Monday, January 19, 2015
This fossil was found in the Carlile Shale Formation of Grant County, South Dakota, USA. He has been carefully extracting the hidden fossil shark teeth. The fossils date to the Cretaceous Period (Turonian). The picture shows what appears to be a Ptychotrygon triangularis sawfish rostral denticle fossil. Field of view (FOV) is about 3 mm.
Thanks to Kenny for the image.