taxonID	type	description	language	source
386587D4E036FFA29BFFFA67FBBFF86F.taxon	type_taxon	Type species. Didelphis pygmaeus Shaw, 1794 by original monotypy.	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
386587D4E036FFA29BFFFA67FBBFF86F.taxon	diagnosis	Generic diagnosis. Differing externally from Distoechurus, the only other genus of acrobatid possums, in the possession of a patagial membrane between the elbow and ankle joints. Beck et al. (2022) list the following cranial and dental features as diagnosing Acrobates from Distoechurus: differing cranially in having a proportionally larger and more inflated neurocranium, a proportionally shorter and deeper rostrum, a vertically expanded sphenorbital fissure; a deep sulcus that houses the transverse canal vein extends laterally from the carotid canal and is floored ventrally by a strut of the alisphenoid vs by the posterior part of the pterygoid in Distoechurus, a narrower mandibular angular process; differing dentally in having P 3 relatively large and subequal in size to P 1 (reduced in Distoechurus), M 1 - 2 square rather than triangular, with the protocone positioned lingual to the paracone, and with more prominent buccal cingula, M 3 relatively large, more than one half the occlusal area of M 2 (Fig. 6).	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
386587D4E036FFA29BFFFCA7FBDCFAF7.taxon	diagnosis	Diagnosis. The diagnosis provided by Aplin, in Aplin and Archer (1987) remains fully applicable.	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
386587D4E036FFA29BFFFCA7FBDCFAF7.taxon	discussion	Remarks. The authorship of Family Acrobatidae has been attributed erroneously in recent works as Aplin & Archer (1987) or Aplin, in Aplin & Archer (1987), e. g., Flannery (1994); Jackson & Thorington (2012). Family Acrobatidae was proposed by Aplin (in Aplin & Archer 1987) but the publication of this work post-dates Strahan’s (1987) usage of the name which was published earlier in that year. Strahan unambiguously proposed Family Acrobatidae as new, accompanied by a diagnosis: “ The family is distinguished from the other phalangeroids by the feather-like tail ”. Although a type genus was not explicitly stated, this did not become a formal requirement under the International Code of Zoological Nomenclature until after 1999. Aplin (in Aplin & Archer 1987) provided a more detailed diagnosis and a discussion of the possible phylogenetic affinities of the group. Beck et al. (2022: 241) provided a more detailed diagnosis based on craniodental apomorphies. Phylogenetic analyses of mitogenomes and genome scale nuclear gene datasets support a sister relationship of acrobatids with a clade comprising, Petauridae, Pseudocheiridae and Tarsipedidae (Mitchell et al. 2014; Duchene et al. 2018).	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
386587D4E037FFA39BFFFA2AFC5DF9C8.taxon	distribution	Recommended common name. Narrow‐toed feather‐tailed glider	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
386587D4E037FFBA9BFFF9B2FE1EF8BA.taxon	materials_examined	Type specimens. [designation by Thomas (1922)]: The lectotype (NHMUK 1888.3.17.1; an adult male) and paralectotype (NHMUK 1888.3.17.2; an adult female) of A. pygmaeus (Shaw, 1794) are spirit preserved bodies, the lectotype with the skull extracted and in good condition, the paralectotype with cranium in situ.	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
386587D4E037FFBA9BFFF9B2FE1EF8BA.taxon	diagnosis	Diagnosis. Tail furred ventrally to the end, tipped with a small nubbin of naked skin (Fig. 3 A); terminal pads of pedal digits 4 and 5 rounded, sub-equal in length and width, and with narrow distal groove; base of hallux with two distinct raised pads, both bearing striae (Fig. 3 C); tail fringe hairs usually with a 1 – 2 mm wide cream emargination; ventral fur grey-based with cream tips, most individuals with entirely cream or white fur on throat and upper chest, rarely extending to lower abdomen (Fig. 4). The ear canal disc, in external view, occupies between 60 and 70 % of the width of the tympanic canal, has a raised narrow central ridge from the base that projects between 50 and 80 % of the width of the disc. The disc in the internal view lacks sculpturing (Fig. 5).	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
386587D4E037FFBA9BFFF9B2FE1EF8BA.taxon	description	Description. Body measurements based on mature adults are presented in Table 3. Small body size, up to 20 g and 85 mm head-body length. Flanks with a narrow patagium, running along the limbs and flank from the wrist to the knee. Soft and silky fur, greyish brown dorsally (Fig. 4 F-I). Most individuals with entirely cream or white fur on throat and upper chest, rarely extending to lower abdomen, otherwise ventral fur grey-based with cream tips (Fig. 4 F-I). Colouring sharply demarcated at the edge of the patagium. Tail equal in length to the head and body (mean = 1.08). Tail markedly distichous and oval in cross-section, with very short ashy-brown fur on the upper and lower surfaces, paler below than above. Tail furred ventrally to the end, tipped with a small nubbin of naked skin. Broad fringe of stiff long hairs along each side (about 8 mm in length), tail fringe hairs usually with a 1 - 2 mm wide cream emargination. The eyes are large, dark and encircled with black fur. The rhinarium is naked, flesh coloured, and deeply cleft; the nostrils are lateral. The ears are moderately large, flattened, oval, and moderately furred externally. Long vibrissae, unusually numerous, extend from the snout, cheeks, and base of each ear with shorter vibrissae extending from the chin. Hands and feet brown above, feet well furred, hands thinly furred. Terminal pads of pedal digits 4 and 5 rounded, subequal in length and width, and with narrow distal groove; base of hallux with two distinct raised pads both bearing striae (Fig. 3 C). Manual digits of relatively similar length in the following order 4> 3> 2> 5> 1. Palmar surfaces hairless, with four broad low pads, three at the base of the fingers and one at the base of the palm. Length of pedal digits in the following order 4> 5> 3> 2> 1. Plantar surfaces hairless with five small pads, four at the base of the toes and one at the base of the foot. Tips of the toes with flattened and striated pads, those on the syndactylous toes 2 and 3 separate and well developed, but smaller than the others. Syndactylous toes 2 and 3 united only to the ends of the first phalanx. Claws sharp and well developed, small in comparison with finger and toepads. Dentition diprotodont. The homology of the anterior dentition of the mandible is not yet determined (Aplin 2015; Kelt and Patton 2020). The dental formula is currently described as I 3 / 1, C 1 / 1?, P 3 / 3? M 3 / 3 = 20 + 16 = 36 (Fig. 6), based on examination of five vouchers (ANWC M 3745, M 6184, M 24072, NHMUK 88.3.17.1, NHMUK 1939.2988). We note that the dental formula we have observed is at variance with previous descriptions in Harris (2015), Nowak (2018), Thomas (1888), but consistent with the dental formula in an illustration of the cranium and dentary of AMS M 3294 in Harris (2015). Variation in cranial and dental morphology is illustrated in Fig. 6 and Supplementary Fig. S 2. We note that the description of cranial and dental morphology for Acrobates in Thomas’ (1888) account is likely based on a composite series of both species of Acrobates given the collection locations he listed for the 17 specimens he had available. Recently, Fabian et al. (2023), in describing several fossil acrobatids, carried out a comparison of dental morphology of extant and extinct acrobatids. From their appendix of material examined we were able to determine that they examined dentaries from 12 specimens of A. pygmaeus and 24 A. frontalis (Supplementary Table S 1). Fabian et al. (2023) effectively had done a “ blind ” analysis of dental variation in that they did not identify the vouchers to species level prior to their examination and subsequently stated that: “ we did not detect significant variation in the dental features we examined, including in m 1 morphology (see Results). We conservatively refer to all of these specimens as A. pygmaeus ”.	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
386587D4E037FFBA9BFFF9B2FE1EF8BA.taxon	distribution	Distribution. Broadly distributed across forested and wooded regions of south-eastern Australia, including: the south-eastern corner of South Australia; Victoria with the exception of the inland draining catchments of the Murray Basin; the Great Dividing Range of New South Wales, north to the Border and McPherson Ranges in south-eastern Queensland; and the coastal drainages of the Great Dividing Range, north at least to the Wallamba River, Tuncurry — AMS M 25806 (Fig. 7). Acrobates pygmaeus is regionally sympatric with A. frontalis throughout its entire range, with numerous instances of syntopy at the level of museum locational data (Supplementary Table S 1).	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
386587D4E037FFBA9BFFF9B2FE1EF8BA.taxon	discussion	Remarks. The lectotype and paralectotype of Didelphis pygmaea Shaw 1794 are leached of all pigment and stained a uniform brown colour. The lectotype is in poor condition, with much of the fur stripped from the venter and from the tail. The manus and pes are clenched and dehydrated, and no details of the plantar surface are discernible. However, the terminal pads of pedal digits 4 and 5, while folded and somewhat shrivelled, seem to be relatively unexpanded and thus consistent with Acrobates pygmaeus rather than A. frontalis. The holotype of Acrobates pulchellus Rothschild, 1892 (NHMUK 1939.2988) is a well-preserved puppet skin and a cleaned skull which lacks the rear part of the skull Supplementary Fig. S 2 B). The purplish-brown colour of the dorsal fur, noted as a diagnostic feature by Rothschild (1892), falls within the observed variation of both species. The tail is short but the density of ventral fur at the tip leaves us in no doubt that it is damaged, possibly to a significant degree. The pes is consistent in morphology with A. pygmaeus, featuring relatively small, ovate terminal pads on each of digits IV-V and a prominent accessory hallucal pad on which the striae are clearly visible. The extensively grey-based ventral pelage of NHMUK 1939.2988, though not strictly diagnostic at species level, nonetheless is also consistent with the typical condition in A. pygmaeus. Our assessment of the holotype of A. pulchellus supports and extends the previous findings of Tate (1938). In all morphological respects, including the morphology of the skull and teeth examined by Tate (1938), the purportedly New Guinean holotype of Acrobates pulchellus resembles A. pygmaeus of south-eastern Australia, rather than northern populations of A. frontalis. Like Tate, we favour the view that the locality details accompanying NHMUK 1939.2988 are spurious and that it was derived from somewhere in south-eastern Australia, a conclusion that could be tested further by DNA sequencing of the holotype. Because of the extensive regional sympatry of the two species of Acrobates in south-eastern Australia, retrospectively identifying which species was used in published studies of Acrobates could be problematic. For instance, Ward (1990) reported four mammae in Acrobates but the specific identity of the material he examined is not known. A possible exception would be for studies carried out on the Southern Tablelands of New South Wales at elevations above 600 m.	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
386587D4E02FFFBC9BFFFD53FE41FB67.taxon	materials_examined	Type specimens. Syntypes QM J 568, 569 (F), 570, three spirit preserved thinly furred pouch young, collected by Mr Kendall Broadbent in the vicinity of Herbert Vale on the Atherton Tableland of north Queensland. According to De Vis (1887: 1134) “ Three specimens caught in the same tree … all three of the same age and size ”; the three are clearly non-independent siblings taken from a nest. QM J 12569 has had the skull removed but this was not located in the QM collection; it may have been sent to Oldfield Thomas in London and formed the basis of his margin annotation regarding examination of a syntype in October 1916.	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
386587D4E02FFFBC9BFFFD53FE41FB67.taxon	diagnosis	Diagnosis. Tail with terminal 2 – 3 mm unfurred ventrally, naked skin forming a prehensile pad (Fig 3 B); terminal pads of pedal digits 4 and 5 broadly heart-shaped, much wider than long and with broad distal groove; base of hallux with a single raised pad bearing striae (Fig. 3 D); tail fringe usually lacks pale emargination; ventral fur usually white or cream to roots, occasional individuals with grey-based fur in groin through to lower abdomen (Fig. 4). The ear canal disc occupies between 70 and 90 % of the tympanic canal, has a raised narrow central ridge from the base that projects between 50 and 80 % of the width of the disc, with the interior of the disc being depressed so that the margin appears raised. The disc in the internal view has sculpturing that emphasises the raised margin (Fig. 5).	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
386587D4E02FFFBC9BFFFD53FE41FB67.taxon	description	Description. Body measurements based on mature adults are presented in Table 3. Small body size, up to 92 mm head-body length. Flanks with a narrow patagium, running along the limbs and flank from the elbow to the knee. Soft and silky fur, greyish brown dorsally. Ventral fur usually white or cream to roots, occasional individuals with grey-based fur in groin through to lower abdomen (Fig. 4 A-D). Colouring sharply demarcated at the edge of the patagium. Tail slightly longer than the head and body (mean = 1.2). Tail markedly distichous and oval in cross-section, with very short ashy-brown fur on the upper and lower surfaces, paler below than above. Tail with terminal 2 - 3 mm unfurred ventrally, naked skin forming a prehensile pad (Fig. 3 B). Broad fringe of stiff long hairs along each side (about 8 mm in length), tail fringe usually lacking pale emargination. The eyes are large, dark and encircled with black fur. The rhinarium is naked, flesh coloured, and deeply cleft; the nostrils are lateral. The ears are moderately large, flattened, oval, and moderately furred externally. Long vibrissae, unusually numerous, extend from the snout, cheeks, and base of each ear with shorter vibrissae extending from chin. Hands and feet brown above, feet well furred, hands thinly furred. Terminal pads of pedal digits 4 and 5 broadly heart-shaped, much wider than long and with broad distal groove; base of hallux with a single raised pad (Fig. 3 D). Claws thin and sharp, barely extending beyond the level of the pads. Manual digits with relatively similar length in the following order 4> 3> 2> 5> 1. Palmar surfaces hairless, with four broad low pads, three at the base of the fingers and one at the base of the palm. Length of pedal digits in the following order 4> 5> 3> 2> 1. Plantar surfaces hairless with five small pads, four at the base of the toes and one at the base of the foot. Mammary formula unknown. Dentition diprotodont with a formula of I 3 / 1, C 1 / 1?, P 3 / 3? M 3 / 3 = 20 + 16 = 36, based on examination of three vouchers (ANWC M 223, M 2960, M 298760). Variation in cranial and dental morphology is illustrated in Fig. 6 and Supplementary Fig. S 2.	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
386587D4E02FFFBC9BFFFD53FE41FB67.taxon	distribution	Distribution. Broadly distributed across forested and wooded regions of eastern Australia, including: the south-eastern corner of South Australia; Victoria with the exception of the Wimmera region; and the Great Dividing Range and its coastal drainages of New South Wales and Queensland, north to Cape Weymouth on the eastern side of Cape York Peninsula. Acrobates frontalis is regionally sympatric with A. pygmaeus throughout large areas of south-eastern Australia, with numerous instances of syntopy at the level of museum locational data (Fig. 7, Supplementary Table S 1).	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
386587D4E02FFFBC9BFFFD53FE41FB67.taxon	discussion	Remarks. Even though the syntypes of A. frontalis are clearly non-independent pouch young, the key diagnostic features of the widespread taxon are evident, including the naked prehensile pad on the underside of the tail tip, the heart-shaped terminal pads on pedal digits 4 and 5, and the accessory striated pad at the base of the hallux. The tail was accurately described by De Vis (1887: 1135) — “ The under surface of the tail is more scantily clothed with shorter white hair continued centrally to an eighth of an inch from the tip, and laterally nearly to the tip ”. The patagium, noted as “ rudimentary ” by De Vis, is represented by a distinct skin fold that extends from the elbow to the knee. The stiffened hairs of the tail fringe, so characteristic of the adult animal, are undeveloped and the future fringe is evident only in the laterally divergent growth of some fine hairs in the basal portion of the tail. De Vis (1887: 1135) reported the accompanying Indigenous name of “ cubbie-cubbie ”. The geographic range of A. frontalis in south-eastern Australia overlaps extensively with that of A. pygmaeus (Fig. 7). However, there are large areas where A. frontalis is the only species present: Queensland north of the McPherson and Border Ranges, coastal New South Wales north of the Wallamba River, the headwater catchments of the Murray River in north-eastern Victoria and southern New South Wales, and the middle reaches of the Murray between Swan Hill in north central Victoria and Renmark in South Australia. Unfortunately, very few of the published studies of Acrobates were conducted in regions of exclusive occurrence. Among the few exceptions are Russell’s (1980) natural history observations on feather-tailed gliders in northern Queensland and studies that include feather-tailed gliders from the northern coast of New South Wales and south-eastern Queensland (Kirk et al. 2000; Hackett & Goldingay 2001; Smith & Agnew 2002; Wormington et al. 2002, Goldingay et al. 2007).	en	P. Aplin, Kenneth, N. Armstrong, Kyle, M. Aplin, Lucy, Jenkins, Paula, Ingleby, Sandra, Donnellan, Stephen C. (2025): Hidden diversity in an ecologically specialized genus of Australian marsupials, the feather-tailed gliders, Acrobates (Diprotodontia, Acrobatidae). Zootaxa 5566 (3): 535-564, DOI: 10.11646/zootaxa.5566.3.5, URL: https://doi.org/10.11646/zootaxa.5566.3.5
