[PaleoMammalogy • 2026] Miyumba chrisdickmani • A New Genus of dasyurid (Marsupialia: Dasyuridae) from the Early Miocene Deposits of the Riversleigh World Heritage Area, north-western Queensland

 

Miyumba chrisdickmani

 Churchill, Archer, Hand & Farman, 2026 

 

DOI: doi.org/10.1071/AZ26024

Artist reconstruction by Neville Garden

 

This study describes Miyumba chrisdickmani gen. et sp. nov., a new genus and species of dasyurid (Marsupialia, Dasyuridae) from Early Miocene deposits of the Riversleigh World Heritage Area in north-western Queensland. This taxon, similar in size to extant species of Antechinus and Sminthopsis (23–33.5 g), is the oldest and most plesiomorphic member of the family Dasyuridae. Character analysis identifies one new lower dental synapomorphy for Dasyuridae that previously lacked any dental synapomorphies uniting the family. Parsimony and Bayesian phylogenetic analysis supports the placement of M. chrisdickmani as the sister taxon to all other dasyurids. These analyses also recover the diminutive Mayigriphus orbus from early Late Miocene deposits of Riversleigh either as a sminthopsine dasyurid or as the second most plesiomorphic member of the family after M. chrisdickmani. Joculusium muizoni from Riversleigh’s Middle Miocene deposits was recovered outside Dasyuridae as a sister taxon by both phylogenetic analyses. Urrayira whitei was recovered by both analyses as a member of the dasyurid genus Planigale, whereas Antechinus yuna and Antechinus yammal were supported as species of Antechinus. Morphological similarity of M. chrisdickmani to extant dasyurids from New Guinea suggests a possible close phylogenetic relationship between these lineages and may represent yet another remnant New Guinean group of rainforest-adapted marsupials that had its origins in the Miocene rainforests of Riversleigh.

Keywords: Dasyuridae, dasyuromorphia, dentition, fossil, Marsupialia, Miyumba, palaeontology, phylogenetics, Riversleigh, systematics

 Miyumba chrisdickmani sp. nov. holotype left dentary QM F62121 shown as MgO coated photographs (a, e–f) and micro-CT images (b–d, g–h):
(a–b), occlusal stereo pairs; (c) anterior view; (d) posterior view; (e) and (g), buccal views; (f and h), lingual views.

Systematic palaeontology

MAMMALIA Linnaeus 1758 

MARSUPIALIA Illiger 1811sensuBeck et al. (2014) 

DASYUROMORPHIA Gill 1872sensuKealy and Beck (2017) 

DASYURIDAE Goldfuss 1820 

Type species: Dasyurus maculatus Geoffroy 1796.

Revised familial diagnosis: All dasyurids possess a p3 that is absent, reduced, or subequal in length relative to p1 and p2. In addition to these features, dasyurids differ from malleodectids in p2 being narrow, blade-like and smaller in all dimensions relative to m2. In addition to the above features, dasyurids differ from thylacinids in metaconids being present on m1 and not highly reduced on m2-4 (except secondarily in S. harrisii), and from the myrmecobiid, M. fasciatus in possessing an unreduced dentition with deciduous premolars lost in adulthood.

†MIYUMBA gen. nov

 Type species: Miyumba chrisdickmani.

Generic diagnosis: 

The new taxon differs from all other dasyurids in the following combination of lower dental features: p1 reduced so as to be approximately subequal (~10% shorter) in length to p1; p2 longer than p1 and p3; no premolar diastemata present; m1 not reduced compared to m2 and m3; paraconid unreduced on m1; metaconids unreduced on all molars; anterior cingulids present; posterior cingulids present; buccal cingulids well-developed on premolars and molars; preentocristids well-developed; three cusps on m4 talonid; and m4 approximately subequal in length compared to other molars.

...

Etymology: The genus name Miyumba comes from the Waanyi word ‘miyumba’, which describes the land where the Riversleigh World Heritage Area is located.

MIYUMBA CHRISDICKMANI sp. nov. 

 

Species diagnosis: As for genus until more species attributable to Miyumba are discovered.

Etymology: The species name chrisdickmani honours the significant contributions of Professor Chris Dickman to our understanding of the biology of dasyurid marsupials and a plethora of other arid-adapted Australian species.

Artist reconstruction of Miyumba chrisdickmani.

Artwork: Neville Garden

 

Timothy J. Churchill, Michael Archer, Suzanne J. Hand and Roy M. Farman. 2026. A New Genus of dasyurid Miyumba chrisdickmani (Marsupialia, Dasyuridae) from the Early Miocene Deposits of the Riversleigh World Heritage Area, north-western Queensland. Australian Zoologist. 45 (2): AZ26024. DOI: doi.org/10.1071/AZ26024 [17 July 2026]

[Mammalogy • 2026] Found Alive After 6,000 years: Modern Records of An ‘Extinct’ Papuan Marsupial, Dactylonax kambuayai (Marsupialia: Petauridae), with A Revision of the Systematics and Zoogeography of the Genus Dactylonax

Dactylonax kambuayai (Aplin, 1999) 

Pygmy Long-fingered Possum

in Flannery, Aplin, Bocos, Koungoulos et Helgen, 2026. 

Records of the Australian Museum. 78; 

DOI: doi.org/10.3853/j.2201-4349.78.2026.3003

 painting by Peter Schouten. 

Abstract

The Pygmy Long-fingered Possum, Dactylonax kambuayai, is the smallest of the striped possums (the petaurid subfamily Dactylopsilinae). It is a ‘Lazarus species’, found living when previously known only from fossils. Recently collected museum specimens, and observations and photographs of living individuals, correspond taxonomically to the only previously reported specimens of D. kambuayai, which are fossil remains from a nearby Holocene location, all occurring in low- to mid-elevation rainforests on the Vogelkop Peninsula of New Guinea. Together with the recent discovery of another Lazarus possum, ‘Petauroides’ ayamaruensis, they represent the only marsupials known as modern animals only from low elevations (below 1000 m) on the Vogelkop Peninsula. Both of these species are diminutive species with enigmatic natural histories. In reviewing the systematics of this species, we demonstrate the distinctness of Dactylonax as a genus-level taxon, and clarify species boundaries in this genus. Dactylonax palpator, the type species of Dactylonax, was previously considered to be a widespread montane taxon, but is recognized here as two separate species: D. palpator is restricted to the Arfak Mountains of the Vogelkop, while D. ernstmayri is widely distributed on the New Guinean Central Cordillera and the Huon Peninsula at elevations above 800 m. Dactylonax palpator replaces, or co-occurs with, D. kambuayai at elevations between around 900 m and 1,400 m on the Vogelkop. We hypothesize that colonization of montane habitats on the Vogelkop by a D. kambuayai-like ancestor gave rise to the larger bodied D. palpator, and dispersal of this lineage to montane habitats in the Central Cordillera gave rise to the highly specialized D. ernstmayri. The fact that the montane taxon of the Vogelkop Dactylonax species couplet was able to migrate eastwards, while the lowland taxon was not, suggests that an unusual elevational zoogeographic filter was in play. We observe that D. kambuayai is thus far recorded from sites where the other small petaurid of New Guinea, Petaurus papuanus, is not recorded or is uncommon.

Keywords: Marsupialia; Petauridae; Dactylonax; kambuayai; palpator; ernstmayri; Lazarus taxon; Vogelkop; New Guinea; systematic review

Photograph of a living female Dactylonax kambuayai, Klalik area, Vogelkop.

Photo: Carlos Bocos.

Dactylonax kambuayai (Aplin, 1999)

Hands of the four extant genera (and three subfamilies) of family Petauridae.
Palmar surfaces of the manus, showing key differences in phalangeal proportions, claws, palmar pads, furring, and patagial development in
(a) Dactylopsila, subfamily Dactylopsilinae (represented by Dactylopsila trivirgata); (b) Dactylonax, subfamily Dactylopsilinae (represented by Dactylonax palpator);
(c) Gymnobelideus, represented by G. leadbeateri (Gymnobelideus McCoy, 1867 is type genus of the new subfamily proposed here: Gymnobelideinae Helgen & Flannery, subfam. nov., Gymnobelideus leadbeateri McCoy, 1867 is type species of Gymnobelideus, the new subfamily and its type genus are both monotypic);
(d) Petaurus, subfamily Petaurinae (represented by P. norfolcensis). Modified from Flannery (1994:61–65). Drawings by Peter Schouten.

Dactylonax kambuayai (Aplin, 1999)—a painting by Peter Schouten.
 This artwork is based on the two modern specimens in the Australian Museum (M.56796 adult female and pouch young M.56797).

Tim F. Flannery; Kenneth P. Aplin; Carlos Bocos; Loukas G. Koungoulos; Kristofer M. Helgen. 2026. Found Alive After 6,000 years: Modern Records of An ‘Extinct’ Papuan Marsupial, Dactylonax kambuayai (Marsupialia: Petauridae), with A Revision of the Systematics and Zoogeography of the Genus Dactylonax. Records of the Australian Museum. 78; 17-34. DOI: doi.org/10.3853/j.2201-4349.78.2026.3003 [06 March 2026]

[Mammalogy • 2025] A Taxonomic Revision of the Bettongia penicillata (Diprotodontia: Potoroidae) species complex and Description of the subfossil species Bettongia haoucharae sp. nov.

 

Bettongia haoucharae  

 Newman-Martin, Travouillon, Warburton, Barham & Blyth, 2025   

 

DOI: doi.org/10.11646/zootaxa.5690.1.1 

Abstract

 The ‘woylie’ (Bettongia penicillata ogilbyi) is a critically endangered potoroid marsupial from the southwest of Western Australia that has been the focus of conservation efforts over the past few decades. Investigations have focused on methods to improve the conservation of the species, including genetic sampling and mapping to better understand their apparent intraspecific diversity and distribution. Most studies have focused on genetic tools to understand the taxon. However, few studies have used subfossil specimens to inform conservation strategies. Apparently genetically distinct subfossil specimens of woylies on the Nullarbor have previously been proposed to represent a new species. In this investigation we use craniodental morphological characters to assess the validity of this species, as well as review the Bettongia penicillata complex as a whole. This investigation used subfossil, modern and historical specimens from museum collections to ensure the broadest coverage for the taxon. This investigation supports the validity of the previously genetically defined Nullarbor species based on unique morphological characters, which is described and named herein as Bettongia haoucharae sp. nov. Furthermore, our analyses suggest that B. p. ogilbyi should be given full species status. After a thorough redescription of craniodental and some postcranial elements, we established (i) Bettongia ogilbyi ogilbyi comb. nov., (ii) an additional two new subspecies, and (iii) a previously synonymised subspecies within the B. penicillata complex. These results highlight the need for a combined approach to taxonomy, with most of the genetic work on B. penicillata in recent years being restricted to living individuals. Our results reveal that B. penicillata can be considered extinct, B. o. ogilbyi is critically endangered with a single individual in the Kanyana Wildlife Rehabilitation Centre and a wild population in the Tutanning Nature Reserve remaining, B. o. sylvatica is critically endangered but recovering as it has been translocated throughout Australia, and B. o. francisca, and B. o. odontoploica are extinct. Future taxonomic work should aim to combine morphology and molecular work using subfossil, modern and historical specimens for a complete understanding of species.

 Mammalia, Bettong, Woylie, Palaeontology, Taxonomy, Marsupialia, Potoroidae

 Bettongia haoucharae sp. nov.

Jake NEWMAN-MARTIN, Kenny J. TRAVOUILLON, Natalie WARBURTON, Milo BARHAM and Alison J. BLYTH. 2025. A Taxonomic Revision of the Bettongia penicillata (Diprotodontia: Potoroidae) species complex and Description of the subfossil species Bettongia haoucharae sp. nov. Zootaxa.  5690(1); 1-69. DOI: doi.org/10.11646/zootaxa.5690.1.1 [2025-09-05]

[Mammalogy • 2025] Marmosa chachapoya • A New Species of Marmosa (Marsupialia: Didelphimorphia: Didelphidae) from Parque Nacional del Río Abiseo, Peru

 

Marmosa chachapoya

Pavan, Abreu, Sánchez-Vendizú, & Voss, 2025

https://hdl.handle.net/2246/7511 

  Researchgate.net/publication/392826622 

 digitallibrary.AMNH.org

Abstract

We describe a new species in the didelphid marsupial genus Marmosa based on a single specimen collected at 2664 m on the eastern side of the Andes in San Martín department, Peru. The new species is closely related to Marmosa lepida (Thomas, 1888) and M. andersoni Pine,1972, in the subgenus Stegomarmosa, but differs from these and other congeneric taxa by mitochondrial and nuclear DNA sequences and by unique external and cranial characters. Diagnostic morphological traits of the new species include gray-based buffy-reddish ventral fur without a midventral zone of self-whitish fur; a remarkably narrow and long rostrum with a very long premaxillary process; absence of postorbital processes; and presence of diastemata among the canines, first premolars, and second premolars in both upper and lower dentitions. Marmosa chachapoya, sp. nov., is one of several recently discovered new species from the Parque Nacional del Río Abiseo, a protected area with remarkably high mammalian diversity.

 

Keywords: Marmosa chachapoya, Marmosa, Peru, Classification, Opossums

  Dorsal, lateral, and ventral views of the holotype skin of Marmosa chachapoya (MUSM 48770).

Holotype of Marmosa chachapoya (MUSM 48770) illustrating morphological features of the new species, including long and narrow rostrum, reddish brown dorsal fur, tail much longer than combined length of head and body, midrostral fur lighter colored than fur of crown, and dark facial mask not extending posteriorly to contact base of ear. Both photos by Pedro Peloso.

Marmosa chachapoya, sp. nov.
 

Pavan, Silvia E.; Abreu, Edson F.; Sánchez-Vendizú, Pamela Y. and Voss, Robert S. 2025. A New Species of Marmosa (Mammalia, Didelphimorphia, Didelphidae) from Parque Nacional del Río Abiseo, Peru. American Museum novitates. no. 4037. https://hdl.handle.net/2246/7511 [2025-06-19] 

 Researchgate.net/publication/392826622_A_New_Species_of_Marmosa_from_Parque_Nacional_del_Rio_Abiseo_Peru

  digitallibrary.AMNH.org/collections/cc9989ac-8437-42b9-80a0-83905bf8ab79

[PaleoMammalogy • 2025] Megafauna Mobility: Assessing the Foraging Range of an extinct macropodid from central eastern Queensland, Australia

 

  Fossil Protemnodon individuals recovered from cave deposits at Mt Etna 

in Laurikainen Gaete, Dosseto, Arnold, Demuro, Lewis et Hocknull, 2025. 

DOI: doi.org/10.1371/journal.pone.0319712 

 

Abstract

Understanding the factors that influence the geographic range of extinct megafaunal species is crucial for reconstructing their ecology and extinction dynamics. For extant herbivores, it has been demonstrated that large body mass provides the potential for greater geographic range. Allometric scaling relationships are observed in placental mammals but have not been well-established for marsupials, in particular, extinct marsupial megafauna. Here, we employ a phylogenetic generalised least squares regression model using extant macropodids to estimate home ranges for individuals from the extinct genus Protemnodon. The regression model predicts a mean home range of 11.6 ±  5.8 km2 This prediction, centred on Mt Etna caves, incorporates several distinct geological features with variable, known 87Sr/86Sr isotope ratios. Fossil Protemnodon individuals recovered from cave deposits at Mt Etna returned 87Sr/86Sr values similar to that of the host limestone, in which the cave systems formed, and the broader Mount Alma Formation. This similarity suggests that individuals foraged close to where they were fossilised, indicating a smaller home range than predicted. Smaller home ranges for individuals with a large body-mass were unexpected, attributed to a unique combination of individual behaviour, diet and/or locomotion regime within stable rainforest environments. Our results suggest that, foraging ranges in marsupial megaherbivores may be more strongly associated with environmental quality rather than body mass. New in-situ uranium-thorium and single-grain TT-OSL ages refine, and are in agreement with, previous interpretations of chronology, indicating that rainforest-adapted fauna persisted at Mt Etna until at least 280 ka. We propose that small home ranges in a stable environment, such as rainforests, predisposed these megafauna macropodids to extinction after 280ka, driven by an increasingly dry and unstable climate. Our results underscore the need for regionally specific biologies of individuals, populations and species when considering extinction pathways for Pleistocene fauna.

 

Cross sections of megafauna enamel. Samples QML1311H-WIGL8543 to QML1312-WIGL8554. Strontium transects can be identified by a series of large depressions running along the enamel/dentine. 

   

Conclusions: 

New TT-OSL ages and open system U-Th ages support previous site chronologies established for the Mt Etna caves, and further constrain fossil accumulation in stratigraphic units QML1311H, QML1311C/D, to ~ 280 – 330 ka. Whilst linear regression models predict species of Protemnodon should have occupied relatively large ranges, strontium isotope measurements of teeth indicate that Protemnodon from Mt Etna Caves had a limited foraging range with movements restricted to the local Mount Alma Formation, with the exception of one specimen originating at least 1 km away. Limited foraging ranges and therefore home range in Mt Etna Protemnodon contrast modelled ranges based on body mass. These differences are suggested to have been driven by resource availability, dietary preferences, and/or locomotory biomechanics, that limited the terrestrial dispersal capacity. Limited foraging ranges support conclusions drawn from extant macropodids suggesting foraging ranges may be more strongly associated with climate and environment. There is potential these limiting ranges may have also been a contributing factor to extinction of Protemnodon at Mt Etna caves. Localised, restricted, populations of Protemnodon may have been well-adapted to a closed-forest environment, however, they were unable to sustain this as intensifying aridification and resource degradation, predisposed them to localised extinction due to their limited dispersal capabilities.

Christopher Laurikainen Gaete, Anthony Dosseto, Lee Arnold, Martina Demuro, Richard Lewis and Scott Hocknull. 2025. Megafauna Mobility: Assessing the Foraging Range of an extinct macropodid from central eastern Queensland, Australia. PLoS ONE. 20(4): e0319712. DOI: doi.org/10.1371/journal.pone.0319712  [April 23, 2025]

https://theconversation.com/fossil-teeth-show-extinct-giant-kangaroos-spent-their-lives-close-to-home-and-perished-when-the-climate-changed-250057

[PaleoMammalogy • 2025] Weirdodectes napoleoni & Malleodectes arenai • A New Genus and Two New Species of malleodectid (Marsupialia: Malleodectidae) from the Middle and Late Miocene Deposits of the Riversleigh World Heritage Area, northwestern Queensland

 

Habitat reconstruction of Riversleigh’s Middle Miocene forests including Malleodectes mirabilis (bottom right), M. wentworthi (top left), Malleodectes arenai (top right) and Weirdodectes napoleoni (bottom left).  

 Churchill, Archer & Hand, 2025

DOI: doi.org/10.1007/s10914-025-09755-6 

 instagram.com/TimboMarsupialman

Illustration by Nellie Pease. 

Abstract

Isolated upper teeth of a new fourth species of Malleodectes, M. arenai sp. nov. and an isolated lower molar representing a new genus of diminutive malleodectid, Weirdodectes napoleoni sp. nov. are described from Riversleigh’s Middle Miocene deposits. In addition, new malleodectid dental material from Middle and Late Miocene deposits at Riversleigh includes the first lower dentition of Malleodectes mirabilis and the first upper dentition of M. wentworthi. Comparisons of the upper and lower dentitions of M. mirabilis and M. wentworthi with that of the putative dasyurid Barinya wangala suggests that taxon is also a malleodectid. Parsimony and Bayesian phylogenetic analyses support a congeneric relationship between M. mirabilis and M. wentworthi, and support assignment of species of Barinya to Malleodectidae. These analyses support previous studies that found malleodectids were more closely related to dasyurids and myrmecobiids than to thylacinids. The snail-eating hypothesis for malleodectids is restricted to species of Malleodectes, with a more generalised durophagous diet suggested for B. wangala. The diet of Weirdodectes napoleoni sp. nov. is unknown but its dentition suggests it was highly specialised.

Keywords: Dasyuromorphia, Malleodectidae, Riversleigh, Taxonomy, Phylogenetics

MAMMALIA Linnaeus, 1758

MARSUPIALIA Illiger, 1811 sensu Beck et al. (2014)

DASYUROMORPHIA Gill, 1872 sensu Kealy and Beck (2017)

†MALLEODECTIDAE Archer et al., 2016

Type species: Malleodectes mirabilis Arena et al., 2011.

MALLEODECTINAE subfamily novum

Head reconstructions and silhouettes of Malleodectes mirabilis and M. wentworthi.

Illustrations by Nellie Pease

†Malleodectes arenai sp. nov.  

Etymology: The species name arenai honours Dr Rick Arena for his contributions to palaeontological and geological research at Riversleigh including description of the genus Malleodectes.

Weirdodectes napoleoni sp. nov. holotype left m1 (QM F61732) microCT images.
a. lingual view; b. buccal view; c. oblique buccal view; ... i. posterior view.

?MALLEODECTIDAE Archer et al., 2016

Subfamily incertae sedis

†WEIRDODECTES gen. nov.

Etymology: The genus name, Weirdodectes, describes the bizarre and highly specialised m1 crown morphology of this taxon which is unlike any other marsupial carnivore currently known.

†Weirdodectes napoleoni sp. nov.  

Etymology: The species name, napoleoni, honours the late Napoleon, the Great Pyrenees Mountain dog who provided unwavering emotional support throughout my undergraduate, honours and PhD years. You will be missed my loyal and magnificent friend, but never forgotten.

Habitat reconstruction of Riversleigh’s Middle Miocene forests including Malleodectes mirabilis (bottom right), M. wentworthi (top left), M. arenai (top right) and Weirdodectes napoleoni (bottom left). 

 Illustration by Nellie Pease. 

 

Timothy J. Churchill, Michael Archer and Suzanne J. Hand. 2025. A New Genus and Two New Species of malleodectid (Marsupialia, Malleodectidae) from the Middle and Late Miocene Deposits of the Riversleigh World Heritage Area, northwestern Queensland. Journal of Mammalian Evolution. 32, 16. DOI: doi.org/10.1007/s10914-025-09755-6 

 instagram.com/TimboMarsupialman/p/DIFZ2qQhaoJ

[PaleoMammalogy • 2024] Badjcinus timfaulkneri, Nimbacinus peterbridgei & Ngamalacinus nigelmarveni • Three New thylacinids (Marsupialia: Thylacinidae) from late Oligocene Deposits of the Riversleigh World Heritage Area, northwestern Queensland, Australia

Nimbacinus peterbridgei (top right) and Ngamalacinus nigelmarveni (bottom right)
interacting with Kuterintja ngama (top left) and Gumardee springae (bottom left). 

Churchill, Archer & Hand, 2024

DOI: 10.1080/02724634.2024.2384595  

Illustration by Peter Schouten.

ABSTRACT

New thylacinid species of Badjcinus, Nimbacinus, and Ngamalacinus are described from upper Oligocene deposits of the Riversleigh World Heritage Area, northwestern Queensland. Badjcinus timfaulkneri, Nimbacinus peterbridgei, and Ngamalacinus nigelmarveni are among the oldest thylacinids yet known and indicate an earlier diversification of the family than previously understood. Maximum parsimony analysis supports a sister group relationship between Ng. nigelmarveni and Ng. timmulvaneyi, but the relationships of the two other new taxa are unresolved. Bayesian dated total evidence analysis using morphological and molecular data supports the generic assignment of B. timfaulkneri and Ng. nigelmarveni but not that of Ni. peterbridgei. Both phylogenies herein support a taxonomic reassignment of Thylacinus macknessi to the genus Wabulacinus, a conclusion also supported by the results of previous studies. Body mass estimates based on molar size regressions indicate body sizes ranging from 3.7 kg to 11.4 kg for the new thylacinid species. Badjcinus timfaulkneri exhibits an extremely deep jaw compared with other thylacinids, with mandibular bending strength analysis suggesting that it was a highly durophagous carnivore much like the modern dasyurid Sarcophilus harrisii. This analysis also suggests Ni. peterbridgei had a dentary more similar in shape to that of plesiomorphic thylacinid faunivores such as Ni. dicksoni and T. cynocephalus suggesting that it had a relatively more generalist faunivorous diet. The molars of Ng. nigelmarveni suggest they were better suited for longitudinal slicing than the molars of B. timfaulkneri and Ni. peterbridgei, indicating a more hypercarnivorous diet compared with that of those species.

SYSTEMATIC PALEONTOLOGY

MAMMALIA Linnaeus, 1758

MARSUPIALIA Illiger, 1811 sensu Beck et al., 2014

DASYUROMORPHIA Gill, 1872 sensu Kealy & Beck 2017

THYLACINIDAE Bonaparte, 1838

BADJCINUS Muirhead & Wroe, 1998

BADJCINUS TIMFAULKNERI sp. nov. 

Species Diagnosis—Badjcinus timfaulkneri differs from all other known thylacinids in possessing the following combination of lower dental features: large diastemas between both p1–p2 and p2–p3; broad talonids on all lower molars; m1 paraconid and paracristid highly reduced; m1 metaconid absent; m2–4 metaconids reduced; m4 larger than m3; three cusps on m4 talonid; two mental foramina below midpoints of m1 and m2. Badjcinus timfaulkneri differs from B. turnbulli in the following lower dental features: p1 less reduced in size relative to p2 and p3; larger diastemata between p1–p2 and p2–p3; anterior cingulid absent on m1; talonids broader on all molars.

Etymology—The species name timfaulkneri honors Tim Faulkner, head of conservation at the Australian Reptile Park and founder of The Devil Ark, for his life’s dedication to the conservation of dasyuromorphian marsupials and of Australian wildlife in general.

Holotype—QM F61721 (Fig. 1) is a near complete right dentary of an adult individual retaining p2 and m1–4, with alveoli for p1 and p3. Dental measurements are given in Table 1.

Nimbacinus peterbridgei (top right) and Ngamalacinus nigelmarveni (bottom right) interacting with Kuterintja ngama (top left) and Gumardee springae (bottom left).

 Illustration by Peter Schouten.

NIMBACINUS Muirhead & Archer, 1989

NIMBACINUS PETERBRIDGEI sp. nov.

Species Diagnosis—Nimbacinus peterbridgei differs from the larger Ni. dicksoni in the following combination of lower dental features: the premolars and molars markedly less robust overall; the anterior cingulid on m2–4 extends beyond the buccal extremity of the trigonid; the cristid obliqua less transverse; the m4 trigonid angle is smaller; the m4 hypoconulid is large and is situated at the transverse midpoint of the talonid, rather than being lingually proximal to the entoconid; the hypoconid and entoconid are less reduced on m4.

Etymology—The species name peterbridgei honors mineralogist Peter Bridge OAM who has dedicated his life to bringing the past of Australia’s natural and cultural history into the present by supporting our paleontological field expeditions and publishing as well as authoring via Hesperian Press hundreds of books about Australia’s extraordinary human and natural history.

Holotype—QM F61723 (Fig. 3) is a right dentary preserving p1, p3, m2–4 and alveoli for p2 and m1. Dental measurements are shown in Table 2.

NGAMALACINUS Muirhead, 1997

NGAMALACINUS NIGELMARVENI Sp. Nov.

 

Species Diagnosis—Ngamalacinus nigelmarveni differs from Ng. timmulvaneyi in the following lower dental features; trigonids broader; trigonid angles smaller; entoconids and hypoconulids not closely twinned on m2–3; m3 entoconid smaller than that cusp in m2; metacristid longer on m2; m4 talonid broader; m4 posterior cristid longer and more transverse, with a distinct postmetacristid valley near the junction of the posthypocristid and prehypoconulecristid; m4 hypoconulid larger; m4 posterior cingulid longer and contacts the base of the postmetacristid valley.

Etymology—The species name nigelmarveni honors British television presenter and naturalist Nigel Marven for his lifetime dedication to inspiring young paleontologists through his unique and daring style of presenting documentaries on ancient life.

 

Timothy J. Churchill, Michael Archer and Suzanne J. Hand. 2024. Three New thylacinids (Marsupialia, Thylacinidae) from late Oligocene Deposits of the Riversleigh World Heritage Area, northwestern Queensland. Journal of Vertebrate Paleontology. e2384595. DOI: doi.org/10.1080/02724634.2024.2384595  

  www.unsw.edu.au/newsroom/news/2024/09/three-new-ancestors-tasmanian-tigers

[PaleoMammalogy • 2024] Opalios splendens, Dharragarra aurora, Parvopalus clytiei, ... • A Diverse Assemblage of Monotremes (Monotremata) from the Cenomanian Lightning Ridge Fauna of New South Wales, Australia

  

Opalios splendens gen. et sp. nov.
Dharragarra aurora gen. et sp. nov.
Parvopalus clytiei gen. et sp. nov.

Flannery, McCurry, Rich, Vickers-Rich, Smith & Helgen, 2024

DOI: 10.1080/03115518.2024.2348753 

artwork: Peter Schouten.

Abstract

Six species of monotremes, three newly described here, occur in the Cenomanian fossil fauna from Lightning Ridge in northeastern New South Wales, Australia, making it the most diverse monotreme assemblage on record. Four species are known from a single specimen, suggesting that diversity remains underrepresented. No other mammal lineages are known from the deposit, although the absence of smaller taxa is likely due to sampling biases introduced by the opal mining process. Early-Late Cretaceous monotremes thus clearly diversified in Australia during the absence of other large-bodied mammalian competitors; and subsequently occupied a wider range of ecological niches than at any other time in their evolutionary history. One new taxon described herein represents a previously unknown monotreme family that combines marked elongation and torsion of the dentary with teinolophid character states, including the retention of five molars. Another shares dental features with ornithorhynchids, while the third is a possible diminutive steropodontid and simultaneously represents the smallest-bodied post-Barremian monotreme. Additional material of Steropodon galmani is also documented, confirming that a Meckelian groove is rudimentary or absent in this taxon, thus adding to the morphological understanding of this unusual monotreme. Lastly, we posit that the loss of teeth in ornithorhynchids may have occurred during the Pleistocene as a result of competition with aquatic hydromyin rodents dispersing to Australia from New Guinea.

Keywords: Mammal, opalized fossils, Late Cretaceous, Mesozoic, Eastern Gondwana

Systematic palaeontology

MAMMALIA Linnaeus, 1758

MONOTREMATA Bonaparte, 1837 or 1838

ORNITHORHYNCHOIDEA superfam. nov.

Diagnosis: Distinguished amongst other Monotremata by torsion of the dentary, whereby the lingual surface of the distal portions of the dentaries faces dorsally and are dorsoventrally flattened (except Tachyglossidae); and the distal portion of the masseteric canal being divided into three wide moieties (except Tachyglossidae).

OPALIONIDAE fam. nov.

Opalios splendens gen. et sp. nov.

Diagnosis: Differs from all monotremes except Teinolophos trusleri in possessing five molars rather than four or fewer (Fig. 2A, B). Differs from T. trusleri in being much larger and possessing: a lower ascending ramus; an articular facet below the level of the toothrow (Fig. 2C, D); a hemispherical depression for insertion of the masseteric musculature on the buccal side of the dentary (Fig. 2C, D); the anterior portion of the dentary twisted (torsion) such that the lingual surface faces dorsally and the anterior dentary is dorsoventrally flattened (Fig. 2A, B, E, F); a much reduced or absent Meckelian groove (Fig. 2E, F); an extremely dorsoventrally shallow mandibular symphysis (Fig. 2F). Differs from all other monotremes except stem and crown ornithorhynchids by exhibiting torsion of the horizontal ramus of the dentary. We consider Opalios splendens to be the basal-most diverging taxon within Ornithorhynchoidea.

Etymology: The genus name refers to ‘opal’ in Greek. The species name refers to the large size and spectacular translucency of the holotype (AM F132596–AM F132599), which provides views of its internal structure.

Family ?ORNITHORHYNCHIDAE Gray, Citation1825

Dharragarra aurora gen. et sp. nov.

Diagnosis: Differs from teinolophids in lacking a Meckelian groove, possessing dentary torsion and three molars, and in lacking diastemata between the premolars. Differs from kollikodontids in possessing an enlarged mandibular canal, in possessing three rather than four molars and in possessing dentary torsion. Differs from Steropodontids in possessing dentary torsion, having a dorsoventrally flattened dentary, and a more reduced posterior molar. Differs from Opalios splendens in having three molars rather than five, and in lacking diastemata between p1 and p2. Amongst ornithorhynchoids, Dharragarra aurora differs from the species of Obdurodon and Ornithorhynchus in having molars with two roots rather than more than two; from Patagorhynchus pascuali in being larger; from Monotrematum sudamericanum in being smaller.

Etymology: The genus name derives from ‘Dharragarra’, meaning platypus in the Gamilaraay, Yuwaalaraay and Yuwaalayaay languages (Ash et al. Citation2003). The species name is Latin for ‘dawn’.

STEROPODONTIDAE Archer, Flannery, Ritchie & Molnar, Citation1985

Steropodon galmani Archer, Flannery, Ritchie & Molnar, Citation1985

?STEROPODONTIDAE

Parvopalus clytiei gen. et sp. nov.

Etymology: Genus name is Latin for ‘small opal’. Species is named for Clytie Smith (Lightning Ridge), who has recovered many opal fossils at Lightning Ridge.

Six monotremes [100 million years ago] at Lightning Ridge, New South Wales, Australia;
clockwise from lower left: Opalios splendens; Stirtodon elizabethae, the largest monotreme of the time; Kollikodon ritchiei, with hot-cross-bun shaped molars; Steropodon galmani, now known from additional opalized fossils; Parvopalus clytiei, the smallest monotreme of the time; and Dharragarra aurora, the earliest known species of platypus.

artwork: Peter Schouten.

Conclusions: 

The co-occurrence of six morphologically distinct fossil mammal taxa (three named herein) in the Lightning Ridge faunal assemblage from the Finch Clay facies of the Griman Creek Formation provides the first indication that Australia was home to a hitherto cryptic diversity of monotremes during the mid-Cretaceous (as predicted by Darlington Citation1957).

• The newly described Opalios splendens is annectant between a teinolophid-like ancestral monotreme morphotype and more derived ornithorhynchoids.

• Dharragarra aurora demonstrates that the lower molar formula typical of Cenozoic ornithorhynchids was established by the Cenomanian.

• New specimens of Steropodon galmani, along with the new small-bodied taxon, Parvopalus clytiei, expand current knowledge of morphological diversity in Cenomanian monotremes.

• The loss of teeth in ornithorhynchids may have been related to ecological displacement caused by the arrival of aquatic rodents in Australia during the Pleistocene.

 

Timothy F. Flannery, Matthew R. McCurry, Thomas H. Rich, Patricia Vickers-Rich, Elizabeth T. Smith and Kristofer M. Helgen. 2024. A Diverse Assemblage of Monotremes (Monotremata) from the Cenomanian Lightning Ridge Fauna of New South Wales, Australia. Alcheringa: An Australasian Journal of Palaeontology. DOI: 10.1080/03115518.2024.2348753 

 www.theguardian.com/australia-news/article/2024/may/27/enormously-exciting-fossils-found-in-nsw-opal-field-suggest-australia-had-age-of-monotremes

[PaleoMammalogy • 2024] Protemnodon viator, P. mamkurra & P. dawsonae • Systematics and Palaeobiology of Kangaroos of the late Cenozoic Genus Protemnodon (Marsupialia: Macropodidae)

Protemnodon viator 

Kerr, Camens, van Zoelen, Worthy & Prideaux, 2024

DOI: 10.11646/megataxa.11.1.1  

news.flinders.edu.au

Abstract

Species of the kangaroo genus Protemnodon were common members of late Cenozoic communities across Australia and New Guinea until their extinction in the late Pleistocene. However, since the genus was first raised 150 years ago, it has proven difficult to diagnose, as have the species allocated to it. This is due primarily to the incompleteness of the type material and a heavy reliance on cheek tooth size and slight variations in premolar form. Along with the rare association between cranial and postcranial material, this has hampered understanding of the palaeobiology of these large-bodied kangaroos. Here we review and re-diagnose Protemnodon, recognising a total of seven species and providing a hypothesis of species interrelationships. The following new synonymies are made: Protemnodon chinchillaensis is synonymised with P. otibandus and P. hopei with P. tumbuna. The following are considered nomina dubia: Protemnodon brehus, P. roechus, P. mimas, P. antaeus, and P. devisi. We reveal that the morphology of the cheek dentition is not as consistently useful for differentiating species of Protemnodon as features of the cranium and postcranial skeleton. As a whole, the species share anatomical features that reflect stability and power in the limb joints, yet they differ in body proportions, and axial and limb morphology. This we interpret as showing locomotory adaptations to different habitats. Of the three Pliocene species, Protemnodon snewini is interpreted as a medium- to high-geared hopper, suggesting proficiency in more open environments, whereas P. dawsonae sp. nov. we infer to have been a medium-geared inhabitant of eastern Australian forests and woodlands. Protemnodon otibandus, with a range extending through the woodlands and forests of eastern Australia into the rainforests of eastern New Guinea, displays adaptations to slower hopping. Its Pleistocene descendant, P. tumbuna, is convergent on the morphology of modern New Guinea forest wallabies, and was likely facultatively quadrupedal. Of the three Australian Pleistocene species, the long-necked P. anak is hypothesised to have been a large, medium-geared, eastern Australian species, and P. mamkurra sp. nov. a robust, low-geared resident of well-wooded southern Australia habitats. By contrast, P. viator sp. nov. was larger but more gracile, suggested to be a medium- to high-geared species convergent in some traits on large extant kangaroos. This and a wide inland distribution point to adeptness in open, arid environments. Protemnodon mamkurra sp. nov. and P. viator sp. nov. occupy the morphospace previously occupied by P. roechus and P. brehus. Overall, the species of Protemnodon exhibit a degree of ecomorphological variation suggestive of a broader array of ecological adaptations than hitherto envisioned.

Australia, New Guinea, Biogeography, Pliocene, Pleistocene, morphology, adaptation, Megafauna, taxonomy, Mammalia 

Australian artist Peter Schouten’s reconstruction of the extinct kangaroos Protemnodon anak (upper) and Protemnodon tumbuna (lower). Despite being closely related, the two were quite different animals in terms of their habitat and their method of hopping.

A near-complete fossil skeleton of the extinct giant kangaroo Protemnodon viator from Lake Callabonna, missing just a few bones from the hand, foot and tail.

Artist Peter Schouten’s impression of south-eastern South Australia during the Pleistocene (~500 thousand years ago) showing many of the plants and animals that lived there alongside Protemnodon.

Isaac A.R. Kerr, Aaron B. Camens, Jacob D. van Zoelen, Trevor H. Worthy and Gavin J. Prideaux. 2024. Systematics and Palaeobiology of Kangaroos of the late Cenozoic Genus Protemnodon (Marsupialia, Macropodidae). Megataxa.  11(1); 1-261. DOI: 10.11646/megataxa.11.1.1

Giant kangaroos bounce back from the past

  news.flinders.edu.au/blog/2024/04/15/giant-kangaroos-bounce-back-from-the-past/