Taeniopteris BRONGN., 1828a

Cleal, Christopher J. & Thomas, Barry A., 2021, Naming Of Parts: The Use Of Fossil-Taxa In Palaeobotany, Fossil Imprint 77 (1), pp. 166-186 : 178

Taeniopteris BRONGN., 1828a

Cycad-like fronds are common in Mesozoic fossil floras but it has been recognised since Thomas and Bancroft (1913) that they include both cycadalean and bennettitalean foliage, two groups of seed plants that are only distantly related. The two types of frond can be easily distinguished if cuticles are preserved but is less so in impressions. Some of these foliage genera are sufficiently distinctive morphologically that they can be separated without cuticles, and hence assigned to either the cycads or bennettites; the distinctive Otozamites BRAUN ( Braun 1844) fronds, for instance, are generally regarded as bennettitalean ( Harris 1969). Other genera are more problematic, however, not least the more or less entire leaves of the Taeniopteris / Nilssonia / Nilssoniopteris complex.

The nomenclatural confusion surrounding the cycadalean Nilssonia BRONGN. ( Brongniart 1825) and bennettitalean Nilssoniopteris NATH. (Nathors 1909) has been extensively discussed ( Cleal and Rees 2003, Cleal et al. 2006, van Konijnenburg-van Cittert et al. 2017, Pott and van Konijnenburg-van Cittert 2017) and need not be repeated here. The lectotype of Taeniopteris as designated by Cleal and Rees (2003: 763) is a very similar shaped leaf but with no cuticle preserved. Since this fossil originated from the Middle Jurassic Stonesfield flora that hardly ever yields cuticles, it will almost certainly be impossible ever to place the Taeniopteris lectotype within the circumscription of either Nilssonia or Nilssoniopteris . To further clarify the situation, Cleal and Rees (2003: 762) emended the diagnosis of the genus containing the type of Taeniopteris so that it can only include species that have not yielded cuticles. By strictly following ICN, therefore, we have ended up with three fossil-genera of essentially similar-shaped entire or near-entire cycadophyte leaves: Nilssonia for those species attributable to the Cycadales , Nilssoniopteris for those attributable to the Bennettitales , and Taeniopteris for the less-well known species unattributable to either group.

Androstrobus SCHIMPER, 1870 emend. by Glasspool et al. in Deng et al. (2014)

Androstrobus has been widely used for adpressions of Mesozoic cycadalean pollen organs (e.g., Harris 1964, Watson and Cusack 2005). The genus was originally defined through relatively generalised morphological characters but van Konijnenburg-van Cittert (1971) refined the definition using cuticular and pollen characters, and a morphologically similar set of fossil cones was separated off into a second fossil-genus, Hastystrobus VAN KONIJNENB.

However, Archangelsky and Villar de Seoane (2004) pointed out that the holotype of Androstrobus preserves neither cuticles nor pollen, so it is impossible to confirm if it in fact belongs to either Androstrobus sensu Konijnenburgvan Cittert (1971) or Hastystrobus . Consequently, Deng et al. (2014) proposed that Androstrobus sensu Konijnenburgvan Cittert (1971) should be placed in a new fossil-genus, Schimperostrobus GLASSPOOL, J.HILTON, S.H.DENG et DEJAX. Deng et al. (2014) also emended Androstrobus to include only cycad-like microstrobili of this type, but for which pollen or cuticles are unknown. As pointed out in Deng et al. (2014), this limits the use of Androstrobus in phylogenetic studies, but is a useful taxon for recording cones of this type in museum collections and geological studies.