Carpolithes SCHLOTHEIM ex BRONGNIART, 1820

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 : 22

Carpolithes SCHLOTHEIM ex BRONGNIART nom. illegit.

Text-fig. 2g

1820 Carpolithes SCHLOTHEIM , p. 418 (nom. inval.).

1822a Carpolithes BRONGNIART , p. 210 (nom. illegit.).

Ty p e. Carpolithes thalictroides BRONGNIART, 1822b, p. 61 , pl. 3, fig. 5; Loc.: upper Oligocene Calcaire de Beauce, Paris Basin, France; ≡ Stratiotes thalictroides (BRONGNIART) CHANDLER, 1923 .

D i a g n o s i s. “Fruits ou semences.”

D i s c u s s i o n. The complex nomenclatural history of this genus has been summarised by Wang (2011), who pointed out that there were a number of 18 th and very early 19 th century records of fossil disseminules as Carpolithus , but they predate the starting point for palaeobotanical nomenclature and so are invalid. The most widely quoted was when Linnaeus (1768: 172) referred to “ Phytolithus fructus ” as Carpolithus , but it is far from clear that he intended it as a generic name: he did not use it as part of a binomial, and it was not listed in the Index Generum Lapidum towards the end of the book.

The earliest validly published name that was intended for such fossils was Carpolithes BRONGNIART 1822a , the spelling of which had been based on the earlier but invalid Carpolithes SCHLOTHEIM, 1820 , who used the name for a range of disseminule-like fossils of different ages. The name Carpolithes BRONGNIART had been used marginally earlier in Cuvier (1822) in combinations Carpolithes thalictroides var. parisiensis BRONGNIART , Carpolithes thalictroides var. websteri BRONGNIART and Carpolithes ovulum BRONGNIART , but neither genus, species nor variety names were accompanied by diagnoses and so were not validly published here; based on the same argument used earlier in the present paper in the section dealing with Phyllites , we cannot accept these as “illustration with analysis” that could validate the publication of the names under ICN, Art. 38.9 (the fossils had also been documented earlier by Alexander Brongniart, 1810: 382, pl. 23, figs 16, 17, but without name). The earliest validly published binomial that was accompanied by diagnosis was C. thalictroides BRONGNIART, 1822b ; Brongniart (1822b) also mentioned Carpolithes ovulum , but only as a name in the caption for his pl. 6, fig. 2, without diagnosis or any other comment, and so was not validly published there. Consequently, as the first validly published species name to be combined by Brongniart with the generic name Carpolithes , C. thalictroides may be taken as the indicated type. However, as that species is the seed of an Oligocene aquatic angiosperm of the extant genus Stratiotes LINNAEUS, 1753 ( Chandler 1923) , Carpolithes BRONGNIART was a later illegitimate taxonomic synonym of Stratiotes and should be supressed.

It might be queried if the diagnosis provided by Brongniart (1822a, b) was sufficient to distinguish Carpolithes from other taxa and therefore validated the publication of that name; it certainly provides few distinguishing characters. However, it is evident that Brongniart (1822a, b) had intended the genus to be used for any isolated fossil fruit or seed of uncertain affinities, and so in this context it does act as an effective diagnosis; Carpolithes BRONGNIART, 1822a was therefore validly published.

“ Carpolithus Mantellii ” was mentioned in a paper by Mantell (1824: 423, pl. 46, figs 3–4) but with no proper diagnosis; it is stated that there are “…veins on its surface…” but the fossils were not described or any indication given of how these “veins” distinguished the fossil from other species (although one of the figures is a close-up of the ovule, this is insufficient to merit designation as “illustration with analysis” that might validate the publication of the name). This species is usually attributed to C. Stokes and P. B. Webb, but their names are not mentioned in the paper, and the fossil is now regarded as an Equisetum LINNAEUS, 1753 tuber rather than a disseminule ( Watson and Batten 1990). The earliest validly published use of the name was Carpolithus ARTIS, 1825 , based on a Pennsylvanian-age disseminule from Yorkshire, UK (type and only described species Carpolithus marginatus ARTIS, 1825 ). Wang (2011) suggested that Artis was merely adopting Brongniart’s (1822a, b) Carpolithes , but Artis did not say this and it is notable that he used this quite different spelling to that of Brongniart (for the other taxa, Artis rigorously maintained the spelling used by the earlier authors). It therefore appears that the earliest published valid name for the fossil-genus envisaged by Brongniart (1822a) for fossil disseminules of uncertain affinities (and which is still widely used today – e.g. Crookall 1976) is Carpolithus ARTIS, 1825 .