On the Cretaceous mangroves of Bahariya Oasis, Egypt

Abstract

Petrified stems (rhizomes) of a fern are described from Late Cretaceous (Cenomanian) beds in Bahariya Oasis. The discovered stems are related to Paradoxopteris stromeri Hirmer (fern rachii) and to Weichselia reticulata Stokes & Webb. (fern pinnae); both already known from also Cenomanian beds of this Oasis. Haloed axes are described from Late Cretaceous (Campanian) beds, i.e. younger than the beds containing the petrified stems. Comments on the nature of these axes, the affinities of the stems and the palaeoenvironments of the area in the two mentioned geologic ages (Cenomanian & Campanian) are given.

Repeated occurrence of palaeo-wildfires during deposition of the Bahariya Formation (early Cenomanian) of Egypt

“…Hirmer 1925Hirmer , 1927Edwards 1933;Koeniguer 1966), which has previously been described from the Bahariya Formation at the Bahariya Oasis (e.g. Hirmer 1925Hirmer , 1927Kräusel 1939;El-Saadawi et al 2016). Silicified remains belonging to this taxon occur frequently in the basal most horizons at Gabal El Dist (Stromer 1914;Hirmer 1925).…”

“…Belcher and McElwain 2008;Belcher et al 2010) but also the intensity of such fern fuelled fires (Belcher and Hudspith 2017). This higher flammability of Cretaceous vegetation is also Based on plant macroremains (mainly impressions, root traces and permineralised remains), Lacovara et al (2003) and El-Saadawi et al (2016) interpreted the palaeoflora of the Bahariya Formation as mainly representing a mangrove, an interpretation supported by the occurrence of typical mangrove-dwelling crabs (Schweitzer et al 2003). It is possible that the charred ferns from Chl 3 were growing in a comparable coastal (mangrove or mangrove-like) ecosystem, as it has been assumed for another deposit also containing abundant fern-charcoal probably related to Paradoxopteris from the Early Cretaceous (Barremian) of Jordan (Abu Hamad et al 2016a).…”

“…Plant remains include Paradoxopteris stromeri, Weichselia reticulata, Nelumbites, Cornaephyllum, Dipterocarpophyllum, Magnoliaephyllum, Ficophyllum, Laurophyllum, Araliaephyllum, Salix and Rogersia (e.g. Kräusel 1924Kräusel , 1939Hirmer 1925;Lejal-Nicol 1987Lejal-Nicol and Dominik 1990;El-Saadawi et al 2016). All these findings represented a unique source of information about the Late Cretaceous North African continental palaeoecosystems, although there are still many aspects of these ecosystems which have so far not been studied in sufficient detail.…”

“…However, besides dinosaurs and other vertebrates as well as invertebrates (e.g. Stromer 1936;Nothdurft et al 2002;Schweitzer et al 2003), the Bahariya Formation provided also a wealth of fossil plants in different preservational states (e.g, Kräusel 1924Kräusel , 1939Hirmer 1925;Lejal-Nicol 1987Lejal-Nicol and Dominik 1990;El-Saadawi et al 2016).…”

“…Schuster 1930;Edwards 1933), which also occurs in the Bahariya Formation at Bahariya Oasis (e.g. Hirmer 1925;Kräusel 1939;El-Saadawi et al 2016). However, due to the fragmentary nature of the charcoal specimens, a definitive assignment to either of these taxa is not possible, although it seems very likely that at least some of the charcoal specimens belong to the same source plant as these taxa.…”