Phyllites 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 : 20-21

Phyllites BRONGNIART

Text-fig. 2f

1822a Phyllites BRONGNIART , p. 210.

Ty p e. Designated here. Populus latior A. BRAUN, 1845, p. 169 (figured Heer 1855: pl. 53, fig. 1); Loc.: Miocene Lagerstätte, Öhningen, Switzerland; ≡ Populus populina (BRONGNIART) KNOBLOCH, 1964 nom. illegit. – see Doweld 2017b.

P l a n t F o s s i l N a m e s R e g i s t r y N u m b e r.

PFN0000147 (for type designation).

D i a g n o s i s. “Feuilles à nervures bien limitées, plusieurs fois divisées ou anastomosées.”

D i s c u s s i o n. It has been widely assumed that Brongniart (1822a) only included a single species ( Phyllites populinus (“ populina ”) BRONGNIART) in this genus (e.g. Kvaček 2008) and that this was therefore the generic type (e.g. Andrews 1955). However, this species name was not validly published by Brongniart (1822a) as no diagnosis was provided and there is only a single outline drawing of a single leaf with partial indication of the venation ( Brongniart 1822a: pl. 3, fig. 4); the latter is totally inadequate to be regarded as “an illustration with analysis” that might validate the name through ICN, Art. 38.9 (the ICN Glossary defines an “analysis” as a “figure or group of figures, commonly separate from the main illustration of the organism … showing details aiding identification”). Moreover, Brongniart (1822a: 238) also mentioned a second species, which he later in the same work described and figured as Phyllites multinervis BRONGNIART ( Brongniart 1822b: 51; pl. 5, fig. 4). Brongniart (1822a) regarded this as rather different from P. populinus , and later transferred it to another genus as Potamophyllites multinervis (BRONGNIART) BRONGNIART, 1828a, p. 114 . Nevertheless, because two species names were mentioned in Brongniart (1822a) the generic diagnosis alone cannot be used to validate either P. populinus or P. multinervis . Consequently, as neither species mentioned by Brongniart (1822a) under Phyllites was validly published there, neither can be regarded as the generic type, and an alternative must therefore be designated (ICN, Art. 38.2).

Nevertheless, the principle behind Andrews’ (1955) suggestion makes considerable sense: Brongniart (1822a) clearly stated that his “ Phyllites populinus ” was the only species that was fully compatible with Phyllites and he used the specimen that he figured under that illegitimate species name to characterise the genus. This species was subsequently transferred to the extant genus Populus L. by Knobloch (1964); but, as pointed out by Doweld (2017b), the resulting combination ( Populus populina (BRONGNIART) KNOBLOCH, 1964 ) was pre-dated by Populus populina JARMOLENKO, 1935 and thus illegitimate. There is, however, another previously published species ( Populus latior A. BRAUN, 1845 ) that has very similar-shaped leaves to Brongniart’s (1882a) “ Phyllites populinus ” specimen and originated from the same locality (the Miocene Lagerstätte at Öhningen, Switzerland). Since both the original Brongniart specimen of “ Phyllites populinus ” and the Braun (1845) type of P. latior are lost, Doweld (2017b) proposed as neotype for both species the same specimen, which also originated from Öhningen. As a consequence P. populinus becomes a later homotypic (“nomenclatural”) synonym of P. latior , and so we propose here that P. latior should be regarded as the type of Phyllites .