A new record of Paradoxopteris stromeri Hirmer 1927 (Monilophyta, incertae sedis) from the Cenomanian of Sinai, Egypt

Abstract

The taxon Paradoxopteris stromeri Hirmer, representing the rachis/petiole/stem of the fern Weichselia reticulata (Stokes et Webb) Fontaine, has a widespread occurrence in the Early–early Late Cretaceous of Northern Africa and the Near East, Europe, as well as South America. Here a new record of this taxon is presented from Cenomanian deposits at Gebel El Minshera in the Northern Sinai (Egypt), adding further evidence for the widespread occurrence of this taxon during this period. The preservation of the here described specimen is peculiar, as it consists of permineralised (silicified) vascular strands, mostly without parenchyma or other tissues preserved in between individual strands. This preservation allows for an observation of the “fishbone” pattern formed by alternating circles of the main vascular strands and perpendicular accessory strands, which makes this taxon unique amongst ferns. Based on the specimen from Sinai, as well as previously figured specimens from the type locality at the Bahariya Oasis in the Western Desert, Egypt, an improved reconstruction of the vascular system of this taxon is proposed.