| Both sides of the same crinoid dorsal cup from the Dennis Limestone, Kansas City Group of the Missourian Stage (306.5-305.5 million years old). Called scientifically, genus Apographiocrinus. Image courtesy Pennsylvanian Atlas of Ancient Life Midcontinent United States, under terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. I edited and processed the photograph through photoshop. |