Holoptychius scale positive and negative, beautifully preserved, from a Rte 15 roadcut. Gift from @historianmichael
Rte 15, Late Devonian, Catskill Fm., PA.
This block actually contains many Holoptychius sp. scales, but the rest are not visible as they are layered onto each other, you can see some to the right of the scale on the outside.
Late Devonian, Catskill Fm,. PA.