Micro-CT investigation of a seed fern (probable medullosan) fertile pinna from the Early Permian Petrified Forest in Chemnitz, Germany

摘要: Abstract A new bipinnate fertile pinna, Sterzelitheca chemnitzensis, bearing alternate synangia, is described from the Chemnitz Petrified Forest, Germany. The specimen occurs in basal volcanic ash of Zeisigwald Tuff Horizon, Leukersdorf Formation, Lower Permian. Because it partially embedded tuffaceous matrix, X-ray micro-computer tomography was employed to investigate complete morphology without mechanical preparation hand specimen. pinna 66 mm long and branched once at least, ultimate pinnae alternately positioned on penultimate axis angles 45–55°. Stalked synangia are bell-like, borne both terminal portion axes 25–60°. smooth walled stalk 3–7 mm long, 1–1.5 mm wide. Individual up 6.5 mm diameter 10 mm bear 12–14 elongated sporangia. Tubular sporangia thin walled, circular transverse section, arranged rim synangial pad around a central hollow. unique preservational mould studied neither permineralisation nor compression–impression. It three-dimensionally preserved, but lacks any organic remains. We provide first detailed three-dimensional features probable medullosan male reproductive organ Fossil Lagerstatte. relatively simple structure offers better understanding Palaeozoic seed ferns.