21559 - Tower Eyed 2.33 Inch Erbenochile issoumourensis Lower Devonian Kettneraspis the optical constants

the optical constants

Agassiz and Desor 1846 (sea urchin)

Subtaxa: Symphysops djebaglensis

-A new species of Argillochelys (Testudines: Cryptodira: Cheloniidae) from the Ouled Abdoun phosphate basin

United States ( Delaware

21559 - Tower Eyed 2.33 Inch Erbenochile issoumourensis Lower Devonian Kettneraspis the optical constantsSpectacularly well detailed specimen. It has been carefully prepared during a long laboratory process. Impressive eyes facets. Finest Quality specimen. Extremely rare and interesting species. With an exaggerated development of the eyes. Probably as an adaptation for a panoramic view of its environment and as a mechanism to quickly detect possible predators. Of course, many of the spines during the preparation process have been fractured and glued