This specimen was collected from an active surface mine in West Virginia. It is an example of the "decurrent" attachment of the leaves to the stem that is the trademark of Alethopteris (i.e. the leaflets attach not as a point, but rather along a continuous strip). This feature is obvious here, but is often much more subtle-- especially in Alethopteris specimens dating back to an earlier time.
This specimen was provided courtesy of Gary Wolfe.
Rock Type: Gray shale
Formation: Kanawha
Interval: Stockton seam
Age: Middle Pennsylvanian Period, approx. 305 million years.
Location: Kanawha County, West Virginia; Catenary Coal. Co., Samples
Mine, located about 10 miles south of Cabin Creek, West Virginia, just west
of Route 79/3. It is an active surface mine and requires permission for
access.
