maggot stone from Kleinnaundorf near Freital, detail
Sterile pinnules (without synangia) of the tree fern Scolecopteris/Psaronius:
three pinnule cross sections (near left margin), pinna cross section with two
pinnules attached to the axis cut lengthwise (centre). Note that both pinnule
and
pinna cross sections look like seagulls in flight because the pinnules are curved
both transversally and longitudinally. Pinnule width up to 2 mm.