| Arthroacantha carpenteri Arkona Formation Arkona, Ontario, Canada Size: 25 cm across the plate See the "Before and After" page to see this piece before it was prepared. | 
|
| Arthroacantha carpenteri Arkona Formation Arkona, Ontario, Canada Size: 25 cm across the plate See the "Before and After" page to see this piece before it was prepared. |
|