BU 42.3/3, chert from Kleinnaundorf/Burgk
Fig.1: Chert with a larger part of a pinna of last-but one order
of a Pecopteris sp.
frond on the polished face (horizontal cut). The fern frond part above is well
visible.
coll. & photograph: G. MÜLLER/Dresden, size
12 x 7,5 cm