Antechinus argentus, Baker, Mutton & Hines, 2013

Baker, Andrew M, Mutton, Thomas Y & Hines, Harry B, 2013, A new dasyurid marsupial from Kroombit Tops, south-east Queensland, Australia: the Silver-headed Antechinus, Antechinus argentus sp. nov. (Marsupialia: Dasyuridae), Zootaxa 3746 (2), pp. 201-239 : 208

Antechinus argentus , sp. nov.

(Silver-headed Antechinus )

Etymology. The species name refers to the predominantly silver colour of the animal’s head, neck and upper body and derives from the Latin argentum.

Material. Holotype: QM JM 19966 , adult male skull, dentary and frozen body (destined for long-term preservation as a puppet skin); Collected 26 April 2013 by T. Mutton and H. Hines from Kroombit Tops NP (60km SSW of Gladstone ). The holotype specimen was photographed live by Qld Museum photographer Gary Cranitch prior to accession into the Qld Museum collection (see Figure 4 ). Figure 5 shows features of the skull, dentary and teeth of the holotype specimen.

Paratypes: all specimens were from the same site as the holotype and were collected over the period December 2012 – June 2013 and have been genetically affirmed as the same taxon (range 0–0.8% divergent at mtDNA). Males: JM19998 , JM19999 , JM20000 , JM20001 ; females: JM10945 , JM19994 , JM19997 .

Holotype locality. The plateau, west and north-west of The Lookout on the eastern escarpment of Kroombit Tops NP, 400km NNW of Brisbane, 60km SSW of Gladstone , south-east Queensland, Australia. Latitude 24°23´36˝ S, longitude 151°02´34˝ E.

Distribution. Currently the only known specimens are from the type locality, a plateau in the vicinity of The Lookout on the eastern escarpment of Kroombit Tops NP. In August 2013, we captured, ear-clipped and released 3 female A. argentus 5.5km further northwest of The Lookout, on the plateau above the eastern escarpment, which we have genetically confirmed.

Diagnosis. Summary of external differences amongst congeners. Antechinus argentus differs clearly from all other antechinus species, in having a combination of striking silver-grey head, neck and shoulders, merging gradually through olive-buff to deep olive-buff on the flanks and rump. A. argentus differs from A. flavipes in being more silvery on the head, neck and shoulders and having subtle olive-buff rump/flanks (rather than much more colourful orange-toned rump/flanks) and pale olive-buff to olive –buff fur on the upper hind feet and underside of tail base (rather than much more colourful orange-toned feet and tail base). A. argentus is usually smaller than eastern Australian A. flavipes . A. argentus differs from A. mysticus in being strikingly silvery/grey (rather than greyish-brown) on the head, neck and shoulders. The eye ring in both these species is broken, but that in A. argentus is more strikingly pale smoke grey and obvious, whereas that in A. mysticus is pale buff and more akin to merely dabs of eyeliner above and below the eye (Tables 1–2).

Species by species differences. For relevance and to facilitate direct comparison, univariate statistics (means, standard deviations, range minima and maxima) are shown for each of the external and internal (cranial/dental) measures for three antechinus species— Antechinus argentus , and the two congeners that may occur in its known geographical proximity: A. flavipes flavipes and A. mysticus (refer Tables 1–3). All ANOVAs of measured variables among all antechinus species were significant (Table 4). Note that due to the low number of A. argentus samples available (3 females, 5 males) despite intensive trapping effort (refer to Discussion for details), often range and mean differences in measured external and craniodental variables indicated minimal overlap but were not significantly different due to broad confidence intervals around means. This was particularly prevalent for differences among females. In the pairwise species by species accounts appearing below, we have noted which characters in A. argentus show least (or no) overlap in ranges and thus most discriminating taxonomic power. A species key to all extant antechinus, based on craniodental measures, indicates relative skull differences between A. argentus and all congeners (see Appendix 1).

Figures

FIGURE 4.(a and b) Photograph of live A. argentus holotype specimen. Photographs are Copyright Gary Cranitch (Qld Museum).

FIGURE 5. A. argentus holotype specimen stereo microscope photographs of skull and dentary (a-f): a. skull, top view; b. skull, bottom view; c. skull, side view; d. dentary, side view; e. dentary, oblique view; f. dentary, top view. Photographs are Copyright Andrew Baker.