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With 14 species recorded, the Miocene La Venta bat fauna is the most diverse bat paleocommunity in South America. It includes the oldest plant-visiting bat in the New World and some of the earliest representatives of the extant families Phyllostomidae, Thyropteridae, and Noctilionidae. La Venta's Notonycteris magdalenensis is an extinct member of the subfamily Phyllostominae, a group of modern Neotropical animalivorous bats, and is commonly included in studies of the evolution of Neotropical bats, but aspects of its biology remain unclear. In this study, we used multivariate dental topography analysis (DTA) to reconstruct the diet of N. magdalenensis by quantitatively comparing measures of molar complexity with those of 25 modern noctilionoid species representing all major dietary habits in bats. We found clear differences in molar complexity between dietary guilds, indicating that DTA is potentially an informative tool to study bat ecomorphology. Our results suggest N. magdalenensis was probably an omnivore or insectivore, rather than a carnivore like its modern relatives Chrotopterus auritus and Vampyrum spectrum. Also, we reconstructed the body mass of N. magdalenensis to be ∼95 g, larger than most insectivorous bats, but smaller than the largest carnivorous bat (V. spectrum). Our results confirm that N. magdalenensis was not a specialized carnivore. It remains to be demonstrated that the specialized carnivory ecological niche was occupied by the same lineage of phyllostomines from at least the middle Miocene. Combining our diet and body-mass reconstructions, we suggest that N. magdalenensis exhibits morphological pre-adaptations crucial for the evolution of specialized carnivory.

The extinction of large-bodied terrestrial ‘megafauna’ during earlier phases of the Quaternary had a significant impact on the transforming structure of ecosystems. However, the causes of such losses remains difficult to determine in part because of a paucity of reliable geochronological information about the taxa involved. This is especially true for continents such as Australia where the majority of extinct species have never been dated using radiometric and/or luminescence methods. Here we add new understanding about the geochronology of the world's largest-ever marsupial, the giant wombat-like Diprotodon optatum, an iconic member of the large herbivore guild of Pleistocene Australia. We present 28 new direct U-series ages (dentine) and 10 luminescence ages (sediments) for D. optatum fossils from three sites in tropical north and subtropical eastern Australia. The luminescence ages lie close to saturation for the tropical northern site of Floraville and therefore indicate minimum ages, and sediments from Gowrie Creek in the Darling Downs were mixed and can only be stated as a likely age range. Nevertheless the results assist in our broader understanding of the timing of persistence of the species. Our results demonstrate that the species roamed the northern tropics at least until the mid-Pleistocene (ca. 420 ka). They likely remained widespread during Marine Isotope Stage 5 (ca. 110 ka) and were abundant on the Darling Downs of eastern Australia. The youngest of the new ages that we report (ca. 60 ka) are from Neds Gully on the Darling Downs, a catchment previously considered by some to contain among the last survivors of the now-extinct megafauna. The new dated record demonstrates that deposits of varying ages occur within the catchment. Consequently, existing species lists that treat Neds Gully as a single faunal assemblage are likely significantly time-averaged and overinflated in terms of palaeo-diversity.

Fluctuating asymmetry (random fluctuations between the left and right sides of the body) has been interpreted as an index to quantify both the developmental instabilities and homeostatic capabilities of organisms, linking the phenotypic and genotypic aspects of morphogenesis. However, studying the ontogenesis of fluctuating asymmetry has been limited to mostly model organisms in postnatal stages, missing prenatal trajectories of asymmetry that could better elucidate decoupled developmental pathways controlling symmetric bone elongation and thickening. In this study, we quantified the presence and magnitude of asymmetry during the prenatal development of bats, focusing on the humerus, a highly specialized bone adapted in bats to perform under multiple functional demands. We deconstructed levels of asymmetry by measuring the longitudinal and cross-sectional asymmetry of the humerus using a combination of linear measurements and geometric morphometrics. We tested the presence of different types of asymmetry and calculated the magnitude of size-controlled fluctuating asymmetry to assess developmental instability. Statistical support for the presence of fluctuating asymmetry was found for both longitudinal and cross-sectional asymmetry, explaining on average 16% of asymmetric variation. Significant directional asymmetry accounted for less than 6.6% of asymmetric variation. Both measures of fluctuating asymmetry remained relatively stable throughout ontogeny, but cross-sectional asymmetry was significantly different across developmental stages. Finally, we did not find a correspondence between developmental patterns of longitudinal and cross-sectional asymmetry, indicating that processes promoting symmetrical bone elongation and thickening work independently. We suggest various functional pressures linked to newborn bats’ ecology associated with longitudinal (altricial flight capabilities) and cross-sectional (precocial clinging ability) developmental asymmetry differenti

Bats show a remarkable ecological diversity that is reflected both in dietary and foraging guilds (FGs). Cranial ecomorphological adaptations linked to diet have been widely studied in bats, using a variety of anatomical, computational and mathematical approaches. However, foraging-related ecomorphological adaptations and the concordance between cranial and postcranial morphological adaptations remain unexamined in bats and limited to the interpretation of traditional aerodynamic properties of the wing (e.g. wing loading [WL] and aspect ratio [AR]). For this reason, the postcranial ecomorphological diversity in bats and its drivers remain understudied. Using 3D virtual modelling and geometric morphometrics (GMM), we explored the phylogenetic, ecological and biological drivers of humeral morphology in bats, evaluating the presence and magnitude of modularity and integration. To explore decoupled patterns of variation across the bone, we analysed whole-bone shape, diaphyseal and epiphyseal shape. We also tested whether traditional aerodynamic wing traits correlate with humeral shape. By studying 37 species from 20 families (covering all FGs and 85% of dietary guilds), we found similar patterns of variation in whole-bone and diaphyseal shape and unique variation patterns in epiphyseal shape. Phylogeny, diet and FG significantly correlated with shape variation at all levels, whereas size only had a significant effect on epiphyseal morphology. We found a significant phylogenetic signal in all levels of humeral shape. Epiphyseal shape significantly correlated with wing AR. Statistical support for a diaphyseal-epiphyseal modular partition of the humerus suggests a functional partition of shape variability. Our study is the first to show within-structure modular morphological variation in the appendicular skeleton of any living tetrapod. Our results suggest that diaphyseal shape correlates more with phylogeny, whereas epiphyseal shape correlates with diet and FG.

The fossil record provides important information about changes in species diversity, distribution, habitat and abundance through time. As we understand more about these changes, it becomes possible to envisage a wider range of options for translocations in a world where sustainability of habitats is under increasing threat. The Critically Endangered alpine/subalpine mountain pygmy-possum, Burramys parvus (Marsupialia, Burramyidae), is threatened by global heating. Using conventional strategies, there would be no viable pathway for stopping this iconic marsupial from becoming extinct. The fossil record, however, has inspired an innovative strategy for saving this species. This lineage has been represented over 25 Myr by a series of species always inhabiting lowland, wet forest palaeocommunities. These fossil deposits have been found in what is now the Tirari Desert, South Australia (24 Ma), savannah woodlands of the Riversleigh World Heritage Area, Queensland (approx. 24-15 Ma) and savannah grasslands of Hamilton, Victoria (approx. 4 Ma). This palaeoecological record has led to the proposal overviewed here to construct a lowland breeding facility with the goal of monitoring the outcome of introducing this possum back into the pre-Quaternary core habitat for the lineage. If this project succeeds, similar approaches could be considered for other climate-change-threatened Australian species such as the southern corroboree frog (Pseudophryne corroboree) and the western swamp tortoise (Pseudemydura umbrina). This article is part of a discussion meeting issue 'The past is a foreign country: how much can the fossil record actually inform conservation?'.

Most morphological and physiological adaptations associated with bat flight are concentrated in the postcranium, reflecting strong functional demands for flight performance. Despite an association between locomotory diversity and trophic differentiation, postcranial morphological diversity in bats remains largely unexplored. Evolutionary developmental biology is a novel approach providing a link between the analysis of genotypic and phenotypic variation resulting from selective pressures. To quantify the morphological diversity of the postcranium in bats and to explore its developmental basis, we reconstructed the postcranial allometric trajectories of nine bat species from different prenatal developmental series, representing five families and both suborders. We tested for allometric growth in Chiroptera and also quantified levels of allometric disparity and inter-trajectory distances. Using a phylogenetic scaffold, we assessed whether ontogenetic differences reflect evolutionary relationships. We found significant allometric growth trajectories in almost all species. Interspecific trajectory distances showed lower variance within Yinpterochiroptera than within Yangochiroptera and between suborders. Each suborder occupied nonoverlapping sections of allometric space, showing changes in the growth rates of specific bones for each suborder. The allometry-corrected disparity was significantly higher in larger species. Statistically significant phylogenetic signal in our results suggests that there is an ontogenetic basis for the postcranial morphological diversity in modern bats. Ancestral state reconstruction also showed an increase in the amount of change in shape with size in the larger species studied. We hypothesize that differences in allometric patterns among bat taxa may reflect a size-dependent evolutionary constraint, whereby variability in body size and allometric patterns are associated.

Background: Self-powered flight is one of the most energy-intensive types of locomotion found in vertebrates. It is also associated with a range of extreme morpho-physiological adaptations that evolved independently in three different vertebrate groups. Considering that development acts as a bridge between the genotype and phenotype on which selection acts, studying the ossification of the postcranium can potentially illuminate our understanding of bat flight evolution. However, the ontogenetic basis of vertebrate flight remains largely understudied. Advances in quantitative analysis of sequence heterochrony and morphogenetic growth have created novel approaches to study the developmental basis of diversification and the evolvability of skeletal morphogenesis. Assessing the presence of ontogenetic disparity, integration and modularity from an evolutionary approach allows assessing whether flight may have resulted in evolutionary differences in the magnitude and mode of development in bats. Results: We quantitatively compared the prenatal ossification of the postcranium (24 bones) between bats (14 species), non-volant mammals (11 species) and birds (14 species), combining for the first time prenatal sequence heterochrony and developmental growth data. Sequence heterochrony was found across groups, showing that bat postcranial development shares patterns found in other flying vertebrates but also those in non-volant mammals. In bats, modularity was found as an axial-appendicular partition, resembling a mammalian pattern of developmental modularity and suggesting flight did not repattern prenatal postcranial covariance in bats. Conclusions: Combining prenatal data from 14 bat species, this study represents the most comprehensive quantitative analysis of chiropteran ossification to date. Heterochrony between the wing and leg in bats could reflect functional needs of the newborn, rather than ecological aspects of the adult. Bats share similarities with birds in the devel

A new Early Eocene bat is described from dental remains recovered from the locality of Prémontré in the Paris Basin, northern France. It is referred to the extinct family Archaeonycteridae, whose members are among the oldest and dentally most plesiomorphic bats. The new archaeonycterid is part of the diverse Prémontré mammal fauna of the late Ypresian (MP10; 50 Ma) which includes a suite of archaic mammals as well as early representatives of modern mammal families. Like other archaeonycterids, this bat may have been an insectivorous perch hunter in paratropical forests that extended into high latitudes during the Early and Middle Eocene. Archaeonycterids disappear from the fossil record after the Middle Eocene, along with many other archaic mammal groups, probably in response to significant changes in climate and habitats as well as competition from crown group bats possibly better adapted to less predictable conditions. http://zoobank.org/urn:lsid:zoobank.org:act:194C2A09-77A6-460C-93E2-017362FD0DC3.

© 2017 Stein et al. Australian Oligo-Miocene mekosuchines (Crocodylia; Crocodyloidea) display wide diversity in cranial shape and inferred hunting strategies. Terrestrial habitus has been inferred for these distinctive predators. A direct morphological signal for locomotion can be expected in the postcrania, particularly the pelvic and pectoral girdles. Here we describe fossil materials of the girdles, which chart their morphological variation in the subfamily from Eocene through to Middle Miocene. Over this period, both girdles undergo significant morphological changes. Notably, an enclosed, ventrally orientated acetabulum in the ilium is developed in one lineage. This recapitulates the erect parasagittal configuration of the pelvic limb seen in many Mesozoic crocodylomorph lineages, suggesting consistent use of erect high-walking in these mekosuchines. Other pelves from the same Oligo-Miocene deposits display morphology closer to modern crocodilians, suggesting a partitioning of locomotory strategy among sympatric meko-suchines. Plesiomorphic and derived pelvic girdles are distinguishable by parsimony analysis, and the earliest examples of the mekosuchine pelvis more closely resemble gavialids and alligatorids while latter forms converge on crown group crocodylids in the morphology of the iliac crest. This suggests that a revaluation of the base relationship of Mekosuchinae within Eusuchia is necessary.

Binfield, P., Archer, M., Hand, S.J., Black, K.H., Myers, T.J., Gillespie, A.K. & Arena, D.A., June 2016. A new Miocene carnivorous marsupial, Barinya kutjamarpensis (Dasyuromorphia), from central Australia. Alcheringa 41, xx–xx. ISSN 0311-5518. A new dasyuromorphian, Barinya kutjamarpensis sp. nov., is described on the basis of a partial dentary recovered from the Miocene Wipajiri Formation of northern South Australia. Although about the same size as the only other species of this genus, B. wangala from the Miocene faunal assemblages of the Riversleigh World Heritage Area, northwestern Queensland, it has significant differences in morphology including a very reduced talonid on M4 and proportionately wider molars. Based on the structural differences and the more extensive wear on its teeth, the central Australian species might have consumed harder or more abrasive prey in a more silt-rich environment than its congener, which hunted in the wet early to middle Miocene forests of Riversleigh. Pippa Binfield [pippa.binfield@outlook.com], Michael Archer [m.archer@unsw.edu.au], Suzanne J. Hand [s.hand@unsw.edu.au], Karen H. Black [k.black@unsw.edu.au], Troy J. Myers [t.myers@unsw.edu.au] Anna K. Gillespie [a.gillespie@unsw.edu.au] and Derrick A. Arena [rick@sitc.net.au], PANGEA Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales 2052, Sydney, Australia.

© 2017 Myers et al. Fourteen of the best sampled Oligo-Miocene local faunas from the Riversleigh World Heritage Area, north-western Queensland, Australia are analysed using classification and ordination techniques to identify potential mammalian palaeocommunities and palaeocommunity types. Abundance data for these faunas are used, for the first time, in conjunction with presence/absence data. An early Miocene Faunal Zone B and two middle Miocene Faunal Zone C palaeocommunities are recognised, as well as one palaeocommunity type. Change in palaeocommunity structure, between the early Miocene and middle Miocene, maybe the result of significant climate change during the Miocene Carbon Isotope Excursion. The complexes of local faunas identified will allow researchers to use novel palaeocommunities in future analyses of Riversleigh's fossil faunas. The utility of some palaeoecological multivariate indices and techniques is examined. The Dice index is found to outperform other binary similarity/distance coefficients, while the UPGMA algorithm is more useful than neighbour joining. Evidence is equivocal for the usefulness of presence/absence data compared to abundance.

Sparassodontans are a diverse but now extinct group of metatherians that were apex predators in South America during most of the Cenozoic. Studying their decline has been controversial mainly due to the scarcity of the fossil record, and different methodological approaches have led to contradictory hypotheses. In an effort to explore questions about their extinction, we developed a novel multi-model statistical approach to analyse all of the currently available data at a continental scale. Using multiple regression analysis and new advances in beta diversity analysis, we used all currently available fossil data at a continental scale to test four competing hypotheses to account for the decline of sparassodontans: competition with placental carnivorans, competition with avian phorusrhacids, non-competitive ecological interactions, and environmental fluctuations. Our results show that the sparassodontan extinction was a gradual process with species disappearing throughout the Cenozoic. Multiple regression analysis supported non-competitive ecological interactions as the best extinction model. Native South American ungulates, African migrants (caviomorph rodents and platyrrhine primates) and didelphimorphians were the groups with the highest statistical significance. Sparassodontan beta diversity increased between South American Land Mammal Ages after the Paleocene–Eocene boundary. Our results demonstrate that ecological modelling techniques illuminate aspects of extinction processes whilst mitigating the limitations of the fossil record. Our study suggests that non-competitive ecological interactions could have been the main driver for sparassodontan extinction rather than, as commonly assumed, a result of competition and/or abiotic fluctuations.

The Chionoidea are a small, southern hemispheric shorebird clade that today includes the Magellanic Plover (Pluvianellidae) and two species of sheathbills (Chionidae). Here we describe the first fossil remains attributable to this group. The two newly described species, the early Miocene Neilus sansomae gen. et sp. nov. from New Zealand and the late Oligocene Chionoides australiensis gen. et sp. nov. from South Australia, are overall more similar to sheathbills, but the mosaic of characters shared with both Chionidae and Pluvianellidae preclude referral to either lineage. Attribution of fossils this age to these lineages also conflicts with divergence dates based on molecular data, as the split between the Magellanic Plover and sheathbills is hypothesised to be more recent. We therefore suggest that these Australasian, plover-size species represent the first record of stem-group taxa within Chionoidea. http://zoobank.org/urn:lsid:zoobank.org:pub:2A5A2FD1-C3B5-4BAB-88D8-5862FE9E7976

Microleo attenboroughi, a new genus and species of diminutive marsupial lion (Marsupialia: Thylacoleonidae), is described from early Miocene freshwater limestones in the Riversleigh World Heritage Area, northwestern Queensland, Australia. A broken palate that retains incomplete cheektooth rows demonstrates that this new, very small marsupial lion possessed the elongate, trenchant P3 and predominantly subtriangular upper molars characteristic of thylacoleonids, while other features of the premolar support its placement in a new genus. Phylogenetic analysis suggests that Microleo attenboroughi is the sister taxon to all other thylacoleonids, and that Thylacoleonidae may lie outside Vombatomorphia as the sister taxon of all other wombat-like marsupials including koalas. However, given limited data about the cranial morphology of M. attenboroughi, Thylacoleonidae is concluded here, conservatively, to be part of the vombatomorphian clade. This new thylacoleonid brings to three the number of marsupiallion species that have been recovered from early Miocene deposits at Riversleigh and indicates a level of diversity previously not seen for this group. It is likely that the different size and morphology of the three sympatric taxa reflects niche partitioning and hence reduced competition. Thylacoleonids may have been the dominant arboreal predators of Cenozoic Australia.

A new specimen of the bizarrely specialised Malleodectes mirabilis from middle Miocene deposits in the Riversleigh World Heritage Area provides the first and only information about the molar dentition of this strange group of extinct marsupials. Apart from striking autapomorphies such as the enormous P3, other dental features such as stylar cusp D being larger than B suggest it belongs in the Order Dasyuromorphia. Phylogenetic analysis of 62 craniodental characters places Malleodectes within Dasyuromorphia albeit with weak support and without indication of specific relationships to any of the three established families (Dasyuridae, Myrmecobiidae and Thylacinidae). Accordingly we have allocated Malleodectes to the new family, Malleodectidae. Some features suggest potential links to previously named dasyuromorphians from Riversleigh (e.g., Ganbulanyi) but these are too poorly known to test this possibility. Although the original interpretation of a steeply declining molar row in Malleodectes can be rejected, it continues to seem likely that malleodectids specialised on snails but probably also consumed a wider range of prey items including small vertebrates. Whatever their actual diet, malleodectids appear to have filled a niche in Australiaâ €s rainforests that has not been occupied by any other mammal group anywhere in the world from the Miocene onwards.

A new fossil crocodile, Ultrastenos willisi, is described from a cranium and postcranial materials collected from the Riversleigh World Heritage Area, northwestern Queensland, Australia. The mandible displays pronounced anterior constriction, approaching that seen in the extant gharial, Gavialis gangeticus, and false gharial, Tomistoma schlegelii. As such, U. willisi potentially filled the ecomorphological niche associated with longirostry that has been previously unaccounted for in Riversleigh's Oligo–Miocene crocodile fauna. The pronounced constriction and features of the posterior cranium further distinguish U. willisi from all other known crocodiles, including the only reported Australian Oligo–Miocene longirostral crocodile, Harpacochampsa camfieldensis, from Bullock Creek in the Northern Territory. Ultrastenos willisi is recognized as a new genus and species assigned to subfamily Mekosuchinae on the basis of phylogenetic analysis.http://zoobank.org/urn:lsid:zoobank.org:pub:7C6DC891-BD9C-4F84-AF7D-409A4A8C720D SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP Citation for this article: Stein, M., S. J. Hand, and M. Archer. 2016. A new crocodile displaying extreme constriction of the mandible, from the late Oligocene of Riversleigh, Australia. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2016.1179041.

NHM Repository

© 2015 Lethaia Foundation. Lineage zones within nine contemporaneous mammalian lineages represented in the Cenozoic fossil vertebrate record from the Riversleigh World Heritage Area in northern Australia are used to resolve a series of faunal intervals from the Late Oligocene to Late Miocene. The results agree with previous interpretations of Cenozoic biostratigraphy, provide evidence for the presence of time horizons subdividing some of the four previously recognized Riversleigh biochrons A-D and also provide evidence supporting the allocation of a greater number of Riversleigh faunas to intervals within the Riversleigh biochronology than other methods in previous work. This approach demonstrates the biostratigraphical potential of evolutionary lineages.