Sigillaria 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 : 14

Sigillaria BRONGNIART nom. cons.

Text-fig. 1c

1821 Rhytidolepis STERNBERG , p. 32 (nom. rej.).

1822a Sigillaria BRONGNIART , p. 209 (nom. cons., non Sigillaria RAFINESQUE ex NUTTALL, 1819 ).

Ty p e. Sigillaria scutellata BRONGNIART, 1822a, p. 222 , pl. 1, fig. 4; MNHN.F.1072.1; Loc.: Middle Pennsylvanian Series, Puits du Moulin, Anzin, Départment du Nord, France (vide Brongniart 1837b: 455).

D i a g n o s i s. “Tiges cannelées, non articululées, impressions en forme de disques disposées en quinconce.”

D i s c u s s i o n. This name is widely used for Palaeozoic lycopsid stems with the spirally formed leaf scars or cushions secondarily arranged in longitudinal rows. Sternberg (1820) placed them within “ Lepidodendron STERNBERG tribe Alveolariae STERNBERG ”, but were later assigned to a separate genus Sigillaria by Brongniart (1822a); although published earlier, Alveolariae does not take precedence over Sigillaria as it is invalid, having been designated as a tribe rather than a taxon at a sub-generic rank (ICN, Art. 37.6). Sigillaria has been conserved since the Vienna ICBN ( McNeill et al. 2006; see Zijlstra 2001 for details of the proposal; also Vogellehner 1968) but only against an earlier homonym Sigillaria RAFINESQUE ex NUTTALL, 1819 (a genus of living angiosperms) and a heterotypic synonym Rhytidolepis STERNBERG, 1821 (the possible conflict with Syringodendron STERNBERG has been dealt with above).

The type of Sigillaria is a stem adpression but Brongniart (1839) later also used the name for an anatomically-preserved fossil (see also ICN, Art. 11.1, Ex. 1). All Sigillaria -like petrifactions that have been described (e.g. Lemoigne 1960) have essentially the same anatomy and there seems little justification for assigning them to a different fossil-genus to the casts or adpressions.