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Three new species of the macropodoid genus Hypsiprymnodon are described from early to middle Miocene fossil deposits in the Riversleigh World Heritage Area, northwestern Queensland. A phylogenetic analysis of macropodoid relationships that includes these new taxa is presented. Monophyly of Macropodinae + Sthenurinae is recovered, as is a clade comprising macropodines, sthenurines, bulungamyines, and potoroids to the exclusion of hypsiprymnodontids and balbarids. Monophyly of Balbaridae is also supported, but hypsiprymnodontids are unresolved at the base of Macropodoidea, rather than forming a clade; this is probably because the new Hypsiprymnodon species described here are currently known from relatively incomplete material (isolated maxillae and dentaries). On the assumption that these extinct forms were ecologically similar to the living species H. moschatus (as suggested by close similarities in dental morphology), their presence in Riversleigh Faunal Zones B and C corroborates previous interp...

A partial skeleton (including both skull and postcranium) and referred dental material attributable to a new species of Oligo-Miocene kangaroo,Nambaroo gillespieae, are described from the Riversleigh World Heritage Area, northwestern Queensland, Australia. The holotype specimen is one of the oldest articulated fossil kangaroo skeletons yet discovered and includes the first postcranial material definitively attributable to the extinct family Balbaridae. Functional-adaptive analysis (including comparisons with modern taxa) of the hindlimb and pedal elements suggests consistent use of quadrupedal progression rather than true hopping. Robust forelimbs and an opposable first pedal digit (lost in most macropodoids) might also indicate limited climbing ability. Cladistic analysis of 104 discrete cranio-dental and postcranial characters coded for 25 ingroup and one outgroup taxon placesN. gillespieaein a plesiomorphic sister clade (also containing other Balbarids and the propleopineEkaltadeta ima) to all other macropodoids. This result supports recent revisions to the classification of kangaroos, which recognize Balbaridae as the most basal macropodoid family-level taxon.

Current lists of species-level representation in faunas from 80 Cenozoic fossil localities at the Riversleigh World Heritage Area have been compiled by review of recorded occurrences of taxa obtained from both published and unpublished sources. More than 290 species-level taxa are represented, comprising mammals, amphibians, reptiles, birds, fishes, molluscs and crustaceans. The data are presented for the purpose of ongoing palaeoecological and biochronological studies.

Exceptionally well-preserved skulls and postcranial elements of a new species of the plesiomorphic stem macropodiform Balbaroo have been recovered from middle Miocene freshwater limestone deposits in the Riversleigh World Heritage Area of northwestern Queensland, Australia. This constitutes the richest intraspecific sample for any currently known basal "kangaroo'', and, along with additional material referred to Balbaroo fangaroo, provides new insights into structural variability within the most prolific archaic macropodiform clade - Balbaridae. Qualitative and metric evaluations of taxonomic boundaries demonstrate that the previously distinct species Nambaroo bullockensis is a junior synonym of B. camfieldensis. Furthermore, coupled Maximum Parsimony and Bayesian phylogenetic analyses reveal that our new Balbaroo remains represent the most derived member of the Balbaroo lineage, and are closely related to the middle Miocene B. camfieldensis, which like most named balbarid species is identifiable only from isolated jaws. The postcranial elements of Balbaroo concur with earlier finds of the stratigraphically oldest balbarid skeleton, Nambaroo gillespieae, and suggest that quadrupedal progression was a primary gait mode as opposed to bipedal saltation. All Balbaroo spp. have low-crowned bilophodont molars, which are typical for browsing herbivores inhabiting the densely forested environments envisaged for middle Miocene northeastern Australia.

The relationship of basal macropodids (Marsupialia: Macropodoidea) from the Oligo-Miocene of Australia have been unclear. Here, we describe a new species from the Bitesantennary Site within the Riversleigh's World Heritage Area (WHA), Ganguroo bites n. sp., new cranial and dental material of G. bilamina, and reassess material previously described as Bulungamaya delicata and 'Nowidgee matrix'. We performed a metric analysis of dental measurements on species of Thylogale which we then used, in combination with morphological features, to determine species boundaries in the fossils. We also performed a phylogenetic analysis to clarify the relationships of basal macropodid species within Macropodoidea. Our results support the distinction of G. bilamina, G. bites and B. delicata, but 'Nowidgee matrix' appears to be a synonym of B. delicata. The results of our phylogenetic analysis are inconclusive, but dental and cranial features suggest a close affinity between G. bilamina and macropodids. Finally, we revise the current understanding of basal macropodid diversity in Oligocene and Miocene sites at Riversleigh WHA.

The near-complete skull of the Giant Rat-kangarooEkaltadeta imais described from a middle Miocene deposit at Riversleigh, north western Queensland. Surprisingly, the results of phylogenetic analysis indicate no special relationship with the only other hypsiprymnodontids for which substantial cranial material is known (Hypsiprymnodon moschatus, H. bartholomaii), but within Macropodoidea, a number of derived features present inE. imaare found only in another extinct taxon, the Balbarinae. Recent studies have suggested that Balbarinae may not represent a basal macropodid clade as thought by most previous authors and furthermore that the subfamily is perhaps distinct from all other kangaroos. In light of these findings an interesting possibility is noted, i.e., that Propleopinae and Balbarinae may represent a monophyletic clade to the exclusion of all other taxa. Preliminary results of investigation into dietary habitus indicate that Propleopinae represents a radiation of medium- to large-sized omnivorous kangaroos. Within this clade it is reiterated that a tendency toward carnivory might be inferred from the relative importance of high amplitude vertical shearing versus horizontal shearing and/or crushing elements in the dentition.

——Cranial and dental remains of the middle to early late Miocene macropodid kangaroo, Ganguroo robustiter, sp. nov., are described. Postcranial remains of G. robustiter were previously desc...

Palaeodiversity and relationships of all groups of Australian mammals are reviewed. The fossil record spanning this time is of variable quality. 'Dark Ages' about which nothing is known in terms of Australian mammal evolution include the late Triassic to late Jurassic, late Cretaceous to late Paleocene and middle Eocene to middle Oligocene. Very little is known about the early Cretaceous and late Miocene. The late Oligocene to middle Miocene record documents the highest levels of biodiversity known for the continent, comparable to that which characterises the lowland rainforests of Borneo and Brazil. Order Monotremata spans at least the last 110 million years and includes four families. The enigmatic Ausktribosphenos from 115 million-year-old sediments in Victoria may represent an archaic monotreme, specialised peramurid or previously undocumented order of mammals but is unlikely to represent a placental as suggested in the initial description. Order Microbiotheria is represented in the early Eocene (~55 mya) by two genera similar in morphology to early Eocene taxa from Argentina. Order Peramelemorphia spans the early Eocene to Holocene and includes at least five families. Order Dasyuromorphia spans at least the late Oligocene to Holocene and includes at least three families. Other dasyuromorphian-like marsupials are indeterminate in terms of family-level affinities. Order Notoryctemorphia spans the early Miocene to Holocene with one family. Order Yalkaparidontia spans the late Oligocene to middle Miocene with one genus. Order Diprotodontia spans the late Oligocene to Holocene, represented throughout by three major groups: Phalangerida (eight families), Vombatomorphia (seven families) and Macropodoidea (at least three families). A possible placental condylarth (Tingamarra) has been recorded from the early Eocene. An archaeonycteridid bat (Australonycteris) is known from the early Eocene. Among bats, the late Oligocene to middle Miocene is dominated by rhinolophoids, many of which have European, Asian and African affinities. Mystacinids, megadermatids, hipposiderids and molossids are well-represented in the Oligocene to Miocene deposits. Vespertilionids are uncommon in the Oligocene to Miocene but become more diverse in the Pliocene to Holocene. Emballonurids and rhinolophids appear for the first time in the Plio-Pleistocene. Pteropodids are unknown prior to the Holocene. Murids span the early Pliocene to Holocene. In the oldest assemblage at Riversleigh, one undescribed lineage resembles archaic forms otherwise only known from the fossil records of Africa and Eurasia.