Filicites sect. Nevropteris BRONGNIART

Cleal, Christopher J. & Thomas, Barry A., 2018, Nomenclatural Status Of The Palaeobotanical “ Artificial Taxa ” Established In Brongniart’S 1822 “ Classification ” Paper, Fossil Imprint 74 (1 - 2), pp. 9-28 : 18

Filicites sect. Nevropteris BRONGNIART

Text-fig. 3d

1822a Filicites (Nevropteris) BRONGNIART , p. 233.

1825 Neuropteris (BRONGNIART) STERNBERG, Tentamen p. xi (nom. rej.).

Ty p e. Filicites (sect. Nevropteris) heterophyllus

BRONGNIART, 1822a, p. 233, pl. 2, fig. 6; Loc. Middle

Pennsylvanian Series, Saarbrücken, Germany (vide Brongniart 1831a: 243).

D i a g n o s i s. “pinnules arrondies, non adherents au rachis, par leur base; les nervures s’épanuoissent du point d’insertion de la pinnule, et sont en general très-distinctes et dichotomes.”

D i s c u s s i o n. The problems surrounding the type of this name have been discussed by Laveine and Blanc (1996) and Laveine (1998) with the result that since the St Louis ICBN ( Greuter et al. 2000) it has been conserved with the specimen figured by Brongniart (1831: pl. 71) as type rather than that figured in the protologue of the basionym. The spelling used by Sternberg (1825) was also conserved against that used by Brongniart (1822a).

The name is now mostly used for Palaeozoic medullosalean foliage ( Cycadopsida) with basally constricted pinnules and non-anastomosed veining. Such fossils have been extensively recorded and studied, with the result that Brongniart’s original fossil-genus has now been segregated into a series of more tightly circumscribed genera based initially on frond architecture ( Gothan 1941) and then later incorporating data on epidermal anatomy ( Cleal et al. 1990, Cleal and Shute 1995). As pointed out by Cleal and Shute (1995) there remain a few species that are morphologically well circumscribed but for which frond architecture or cuticles are insufficiently known for them to be placed in this more refined classification. These tend to be retained within Neuropteris but with no implication being made that they are related to the type of that fossil-genus ( N. heterophylla ).

The name is usually used for adpression fossils, although it can also be used for anatomically-preserved fossils if sufficient morphological characters are available, such as from paradermal sections (e.g. Beeler 1983). However, if only anatomical data are available, Neuropteris is difficult to distinguish from other types of medullosalean frond (e.g. Alethopteris STERNBERG, 1825 ) and so the more widely circumscribed fossil-genus defined exclusively on anatomical characters ( Myeloxylon BRONGNIART, 1849 ) is best used.

Figures

Text-fig. 3. Illustrations of specimens in Brongniart (1822a, b) that were originally generic or section types but which have been subsequently supressed; see text for further details. All reproduced half original size, except d which is original size. a) Lycopodites taxiformis SCHL. ex BRONGNIART. b) Filicites (Glossopteris) dubius BRONGNIART (≡ Glossopteris dubius (BRONGNIART) STERNBERG), Pennsylvanian Subsystem. c) Asterophyllites radiatus BRONGNIART (≡ Annularia radiata (BRONGNIART) STERNBERG). d) Filicites (Neuropteris) heterophylla BRONGNIART (≡ Neuropteris heterophylla (BRONGNIART) STERNBERG), Pennsylvanian Subsystem, Saar-Lorraine.