The piece of chert shown here (Fig.1) has a size of 12 x 7,5 cm. After carefully choosing a suitable plane for cutting and with some luck I obtained a larger part of a pinna of last-but one order of a Pecopteris sp. frond on the polished face. (The form genus Pecopteris covers the sterile fronds of all Scolecopteris species.) Judging from the many clearly visible forked pinnule veins, it cannot be a sterile part of Scolecopteris elegans. However, it is certainly some Scolecopteris species because pinnules with forked veins and pinnules with synangia are present in other fragments of the same chert type.

						Fig.1: chert with pinna of a Pecoperis frond (overview)
						Fig.2: chert with pinna of a Pecoperis frond (detail)
						Fig.3: pinnules with forked veins

During my work underground in the "Willi Agatz" mine (Dresden) I succeeded in collecting fern fossils in every accessible coal seam, notably seam 5 and Lette 7 therein (Lette=barren layer). Owing to the well-known good preservation in light-colored siltstone [1] the pinnule veins were clearly seen. The variety of ferns seen in the siltstone suggests the assumption that the cherts, too, contain more ferns than only one species, Scolecopteris elegans. Numerous samples, similar as the one shown here, support this assumption.

text & photographs: G. MUELLER/Dresden