| Top and bottom--Two specimens of the bark of an extinct scale tree known scientifically as genus-species Lepidodendron cf. acukatum from the upper Mississippian Diamond Peak Formation, White Pine County, Nevada. Lepidodendron is most closely related to the modern quillworts--not the club mosses, as is often erroneously related. Scale is in centimeters. Photographs courtesy Chris G. Mattinson; I edited and processed the images thorugh photoshop. |