Dorcopsis chalmersii Miklouho-Maclay, 1884a

Parnaby, Harry & Gill, Anthony C., 2021, Mammal type specimens in the Macleay Collections, University of Sydney, Zootaxa 4975 (2), pp. 201-252 : 224-227

Dorcopsis chalmersii Miklouho-Maclay, 1884a

Proc. Linn. Soc. N.S.W. (ser. 1) 9 (3), 570, plate 19. (29th November 1884).

Description read at the 30th July 1884 meeting of the LSNSW.

Current name. Grey Forest Wallaby Dorcopsis luctuosa luctuosa ( D’Albertis, 1873) following Groves & Flannery (1989).

Taxonomic status. Not considered to be a valid species since Thomas (1888), who synonymised it with Dorcopsis luctuosa .

Holotype. M.1029, unsexed skull and mandibles ( Fig. 9 ), determined here. Stated in the original account to be a young adult male preserved in alcohol, obtained by Miklouho-Maclay from locals in December 1880. The fate of the body is unknown.

Type locality. Papua New Guinea mainland, “opposite Dinner Island” [= Samarai Island], Milne Bay Province, Papua New Guinea.

Comments. The original account states that the description was based on one animal, a young adult male. We are not aware of any published or unpublished reference to the type material of Dorcopsis chalmersii since Miklouho-Maclay’s original account. Nor have we found documentation indicating that it was in Macleay’s Collection. Neither the MAMU 1890s Catalogue nor MAMU Mammal Register list this species and the three Dorcopsis specimens listed in both documents are all accounted for and remain in the Collection. These are the presumed types of D. macleayi and D. beccarii , along with a young male mounted skin listed as Dorcopsis luctuosa . The last-mentioned specimen is probably M.379, a skin mount with skull inside. The rear molars of the two former specimens were fully erupted, unlike those illustrated for the holotype of D. chalmersii . Miklouho-Maclay (1885d) illustrated a stuffed specimen that he cited as Dorcopsis luctuosa from Port Moresby, which is consistent with the mounted skin M.379. That specimen is a young male with the skull in situ, and the corroded teeth are consistent with the effect of storage in brine observed in other specimens from New Guinea obtained from Goldie.

A skull that we are confident is that of the holotype was discovered in the Collection during this study in 2016. The cranium and both dentaries (M.1029) were labelled “ Dorcopsis ?sp.” but without further data. The unnumbered skull and mandible were registered as M. 1029 in the 1960s and listed as “macropod skull” without further data in the MAMU Register. A tag subsequently attached to the skull at an unknown date identified it as “ Dorcopsis ?sp.”. The registration date is not recorded for most specimens in the Register, but M.1029 would have been registered in 1965 or 1966, given that M.1166–M.1176 were assigned to specimens in 1966 as indicated in the Register.

Several lines of evidence strongly support our conclusion that M.1029 is the missing holotype skull. First, the skull closely resembles the one illustrated in Miklouho-Maclay’s plate 19, as exemplified by the ventral view ( Fig. 10 ). In particular, the close match in size and shape of the outline of the remnants of the two posterior palatal vacuities of M.1029 with those of plate 19 is significant because these are thought to be highly individualistic in macropods (Dr Ken Aplin pers. comm. 2015). Second, skull measurements closely match those given by Miklouho-Maclay in the original description and additional measurements we took from his skull illustrations ( Table 5 ). The three measurements showing the greatest discrepancy are within 2 mm of Miklouho-Maclay’s (see Table 5 ) and were taken from his fig. 5. Differences between the left and right side of the skull and jaw in his figs 5 and 6 are consistent with optical distortion. It is likely that Miklouho-Maclay prepared the skull illustrations either from camera lucida or perhaps by tracing photographs.

Two additional considerations provide circumstantial support that M.1029 is the holotype. The skull is unusual in that a neat, empty cavity has been excavated in the bone where the upper and lower left permanent premolars and first molars would have been embedded ( Fig. 9 ). This feature is not unique to the holotype and other macropod skulls in the MAMU have cavities from which permanent premolars have been extracted. However, M.1029 is consistent with Miklouho-Maclay’s description of how he employed a dentist who neatly extracted teeth embedded in the skull and jaw from the same side of the skull as the cavities in M.1029. Although he does not indicate from which side the teeth were extracted, the permanent premolar and first molars illustrated in his plate 19 are clearly from the right side. A faint ink inscription of “M. M.” is visible on the rear, outer surface of the right zygomatic arch. This might stand for “Macleay Museum”, or “Miklouho-Maclay” but we are not able to resolve this. The bone surface is rough and pitted, and if Miklouho-Maclay had initialed the specimen, perhaps it was necessary to use solid straight lines, rather than the more graceful artistic flourish of other material with his initials in the Macleay Collection.

A distinctive hole in the distal ear margin of the holotype is evident in fig. 1 of the original account and is a potentially useful feature for recognising the type skin, though it might not have survived. It is not clear from his account whether Miklouho-Maclay preserved an entire body in alcohol, a skinned body, or only the head. We suspect that he did preserve the skin, given the level of detail provided for the dorsal fur patterns in D. chalmersii in a subsequent paper that discussed the distinctive, circular hair whirls of macropods ( Miklouho-Maclay 1885d).

A search of Miklouho-Maclay’s archival documents might reveal when the holotype reached the Macleay Museum. Miklouho-Maclay typically indicated in which collection specimens of his new species were housed but as he did not do so in his account of Dorcopsis chalmersii , the holotype was possibly in his private collection at the time the description was published. Either he gave the holotype to Macleay, or it might have been included in a donation of some of his specimens from Lady Miklouho-Maclay in 1889. A list of material from that donation in the MAMU Donations Book for 1889 is too general to resolve this.

Figures

FIGURE 9. Skull of M.1029, likely holotype of Dorcopsis chalmersii Miklouho-Maclay, 1884a [= Dorcopsis luctuosa (D’Albertis, 1873)]. Right side of skull and dentary have cavities to remove unerupted teeth, as described by Miklouho-Maclay. (© Chau Chak Wing Museum, photo Stuart Humphreys 2016). Scale bar = 2 cm.

FIGURE 10. Skull of M.1029, likely holotype of Dorcopsis chalmersii Miklouho-Maclay 1884a [= Dorcopsis luctuosa (D’Albertis, 1873)], compared with illustrations of the type skull reproduced from Miklouho-Maclay’s original account. Scale bar = 1 cm. (© Chau Chak Wing Museum, photo Stuart Humphreys 2016).