Phalangista pinnata Ramsay, 1877a

Parnaby, Harry & Gill, Anthony C., 2021, Mammal type specimens in the Macleay Collections, University of Sydney, Zootaxa 4975 (2), pp. 201-252 : 220-221

Phalangista pinnata Ramsay, 1877a

Proc. Linn. Soc. N.S.W. (ser. 1) 2 (1), 12. (July 1877).

Description read at the 29th January 1877 meeting of the LSNSW.

Current name. Feather-tailed Possum Distoechurus pennatus ( Peters, 1874) following Tate & Archbold (1937).

Taxonomic status. Not accepted as a valid species or subspecies since Peters & Doria (1881), who treated it as a synonym of D. pennatus ( Peters, 1874) . Currently only one species of Distoechurus is recognised, but a taxonomic revision of the genus is needed ( Helgen et al. 2011) and D. “ pennatus ” could consist of three or more species ( Aplin 2015).

The nomenclatural status of the name P. pinnata Ramsay is open to interpretation. Over the past seven decades the name usually does not appear in synonymies (e.g., Laurie & Hill 1954; Van der Feen 1962; Flannery 1995; Groves 2005; Aplin 2015) but it is unclear whether this was an oversight or reflects a decision that the name is a nomen nudum. Parnaby et al. (2017) treated P. pinnata as a spelling error of P. pennata Peters but the issue is reexamined here.

In the decades immediately following publication, P. pinnata Ramsay was widely accepted as a newly proposed name but a synonym of Phalangista (Distoechurus) pennata Peters, 1874 . Peters & Doria (1881) and Lydekker (1896) thought P. pinnata was a misspelling of P. pennata Peters. Peters & Doria (1881) further state their belief that in any case, the Ethel River specimens were probably only a synonym of P. pennata Peters. Thomas (1888) elevated Distoechurus to generic rank with one species, D. pennatus Peters , and Phalangista pinnata Ramsay as a synonym. The nomenclature proposed by Thomas (1888) was adopted by Ogilby (1892) and the MAMU 1890s Catalogue, neither of which mention P. pinnata Ramsay.

During the first half of the 20th century, Phalangista pinnata Ramsay was often listed in the synonymy of D. pennatus Peters (e.g., Jentink 1907; Cabrera 1919; Tate & Archbold 1937). Although Thomas (1888) initially recognised P. pinnata Ramsay as a synonym, he changed his mind ( Thomas 1920), believing that pinnata was a spelling error when he proposed Distoechurus pennatus dryas , stating that Ramsay’s material was probably the same subspecies as dryas. Otherwise, he might have to admit that dryas could be a junior synonym of pinnata Ramsay.

Syntypes. M.928, female, body in alc., skull in situ; M.929, juvenile, in alc., skull in situ, both from Ethel River , Papua New Guinea. They are almost certainly the ones listed in the MAMU 1890s Catalogue , which lists two specimens only under “ Distocherus [sic] pennatus Peters ”, an adult female and a young, both in alcohol, from Ethel River . Fulton (2016a) established that the Chevert party collected at Ethel River on 25th to 26th August 1875. It appears that only two specimens were collected on the Chevert Expedition .

Locality. Ethel River, Hall Sound, Central Province, Papua New Guinea.

Comments. The two specimens M.928 and M.929 are most likely those examined by Ramsay (1877a) but their type status depends on whether P. pinnata Ramsay is considered to be an available name as defined by the Code.

In his paper on mammals of the Chevert, Ramsay (1877a) gave a brief and ambiguous account without illustrations, reproduced here in its entirety:

“ PHALANGISTA PINNATA

Adults and young of this pretty species were obtained on the Ethel River, New Guinea; the young resemble the adults; the white stripe down the forehead, however, is proportionately broader.”

Was Ramsay referring to the name proposed by Peters but had inadvertently misspelt pinnata for pennata (pinnatus and pennatus , respectively, when combined with Distoechurus )? A further ambiguity stems from Ramsay’s passing remark that adults and young were alike except for a wider dorsal head stripe of the latter. Did he intend to erect a new species P. pinnata , diagnosing it on an implied wider dorsal stripe than P. pennata Peters , or did he simply note that the dorsal stripe of the young was wider than the adult? Although the account by Peters did not include illustrations or measurements of the head stripe, this information could have been conveyed in correspondence with Ramsay.

Further confusion arose because Ramsay did not indicate an intention to propose a new name. Although the description of a new species or subspecies by convention includes indication of such intent, usually by sp. nov. or similar, this omission alone does not invalidate the description according to the Code. In his paper on Chevert mammals, Ramsay presented accounts for eleven other species in addition to P. pinnata , but his citation of species authorship was inconsistent. He provides authorship for eight species and literature citation for all but one of these. His intention to propose a further three new names is clearly indicated. One of these, Perameles macroura var. torosus , which appears on the same page as his account of P. pinnata , also failed to include subsp. nov. after the name. However, it is clear from the text that Ramsay was proposing a new race torosus .

Perhaps Ramsay and Peters independently coined similar species names, both alluding to the diagnostic tail morphology. We do not know whether Ramsay was aware of the description by Peters (1874), but the journal would surely have reached Ramsay during the intervening years before his paper was read at the January 1877 meeting of the LSNSW. If he was, the Chevert specimens of Distoechurus might have confronted him with a dilemma that he resolved by calculated ambiguity. It is likely that he did not have sufficient information or time to resolve the taxonomic status of his specimens even though they could reasonably be expected to be a new species: Peters’s description was based on a specimen from the Vogelkop, geographically distant from Ethel River. The ambiguity in Ramsay’s account would buy time for him to claim a new species if he subsequently determined that it was distinct from the species described by Peters, and save face if it wasn’t.

We have not found any indication of Ramsay’s opinion about the status of P. pinnata Ramsay subsequent to publication of the name. The species was very rare in world collections and it appears that there were no specimens in the AM Collection during Ramsay’s lifetime from which we could check the original nomenclature applied to specimen labels.

There seem to be three interpretations of how the Code could be applied to this name. First, P. pinnata is a misspelling of P. pennata Peters and Ramsay had neglected to cite Peters as the author. Second, irrespective of his intent, Ramsay introduced a new name to the taxonomic literature: Phalangista pinnata Ramsay is not a nomen nudum because a description, though poor, was provided. Ramsay did not state which species he was comparing in his diagnosis, but this would have been implicit, given that P. pennata Peters was the only other species named at that time. Third, the name is a nomen nudum, i.e. a name invalided by having no diagnosis, Ramsay merely noting that the young have a proportionately broader face stripe than adults. Ultimately, the status of this name is best resolved as part of taxonomic revisionary work. Our intent is to draw attention to the material and the nomenclatural issues involved. Our interpretation is that Ramsay introduced a valid name, even if unintentionally and by a comedy of errors.