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Global biodiversity loss continues unabated, and in Australia, the rate of recent mammal extinctions is among the worst in the world. Meanwhile, the diversity among and within many endemic mammal species remains undescribed. This information is crucial to delineate species boundaries and thus inform decision‐making for conservation. Sminthopsis virginiae (the red‐cheeked dunnart) is a small, dasyurid marsupial found in four disjunct populations around the northern coast of Australia and New Guinea. There are three currently recognized subspecies, each occupying a distinct geographic location. Sminthopsis v. virginiae occurs in Queensland, S. v. rufigenis is distributed across New Guinea and the Aru Islands, and S. v. nitela has populations in the Top End of the Northern Territory and the Kimberley region of Western Australia. Previous molecular work has suggested the current subspecies definitions are not aligned with DNA sequence data, though the sampling was limited. We undertook a comprehensive genetic and morphological review of S. virginiae to clarify relationships within the species. This included mitochondrial (CR, 12S, and cytb) and nuclear (omega‐globin, IRBP, and bfib7) loci, and morphometric analysis of skulls and whole wet‐preserved specimens held in museums. Maximum Likelihood and Bayesian phylogenetic analyses resolved samples into two distinct clades, demarcated by the Gulf of Carpentaria in Australia's north. Sminthopsis. v. nitela was consistently separated from S. v. virginiae and S. v. rufigenis, based on the overall body and skull size and craniodental features, while S. v. virginiae and S. v. rufigenis were more difficult to distinguish from each other. Thus, we redescribed S. virginiae, recognizing two species, S. nitela (raised from subspecies) and S. virginiae (now comprising the subspecies S. v. virginiae and S. v. rufigenis). This study highlights the importance of recognizing cryptic mammal fauna to help address the gap in our knowledge about diagnosing diversity during a time of conservation crisis. [ABSTRACT FROM AUTHOR]

The stripe-faced dunnart (Sminthopsis macroura) is one of the most widespread dasyurids in Australia, occurring mostly in semiarid and arid habitats. It is not known to inhabit coastal regions of southern Australia, and no records have previously been recorded from latitudes greater than 28.5°S in Western Australia. Following the capture of an individual south of the known species range provisionally identified based on external morphology as S. macroura , we used DNA and craniodental morphology to corroborate the specimen's identification, providing a record of the species at Eucla, Western Australia. This represents a large range extension for S. macroura of 630 km from the nearest confirmed records of the species in Western Australia and South Australia. A suspected stripe-faced dunnart (Sminthopsis macroura) was captured at a coastal dune site near Eucla, Western Australia. The identity of the specimen was corroborated through DNA sequencing and morphological examination. This represents a range extension into novel habitat for the species in southern Western Australia. Photograph by Joshua Keen, Biota Environmental Sciences. [ABSTRACT FROM AUTHOR]

Previous analyses of relations, divergence times, and diversification patterns among extant mammalian families have relied on supertree methods and local molecular clocks. We constructed a molecular supermatrix for mammalian families and analyzed these data with likelihood-based methods and relaxed molecular clocks. Phylogenetic analyses resulted in a robust phylogeny with better resolution than phylogenies from supertree methods. Relaxed clock analyses support the long-fuse model of diversification and highlight the importance of including multiple fossil calibrations that are spread across the tree. Molecular time trees and diversification analyses suggest important roles for the Cretaceous Terrestrial Revolution and Cretaceous-Paleogene (KPg) mass extinction in opening up ecospace that promoted interordinal and intraordinal diversification, respectively. By contrast, diversification analyses provide no support for the hypothesis concerning the delayed rise of present-day mammals during the Eocene Period. [ABSTRACT FROM AUTHOR]

Pseudocheiridae (Marsupialia: Diprotodontia) is a family of endemic Australasian arboreal folivores, more commonly known as ringtail possums. Seventeen extant species are grouped into six genera ( Pseudocheirus, Pseudochirulus, Hemibelideus, Petauroides, Pseudochirops, Petropseudes). Pseudochirops and Pseudochirulus are the only genera with representatives on New Guinea and surrounding western islands. Here, we examine phylogenetic relationships among 13 of the 17 extant pseudocheirid species based on protein-coding portions of the ApoB, BRCA1, ENAM, IRBP, Rag1, and vWF genes. Maximum parsimony, maximum likelihood, and Bayesian methods were used to estimate phylogenetic relationships. Two different relaxed molecular clock methods were used to estimate divergence times. Bayesian and maximum parsimony methods were used to reconstruct ancestral character states for geographic provenance and maximum elevation occupied. We find robust support for the monophyly of Pseudocheirinae ( Pseudochirulus + Pseudocheirus), Hemibelidinae ( Hemibelideus + Petauroides), and Pseudochiropsinae ( Pseudochirops + Petropseudes), respectively, and for an association of Pseudocheirinae and Hemibelidinae to the exclusion of Pseudochiropsinae. Within Pseudochiropsinae, Petropseudes grouped more closely with the New Guinean Pseudochirops spp. than with the Australian Pseudochirops archeri, rendering Pseudochirops paraphyletic. New Guinean species belonging to Pseudochirops are monophyletic, as are New Guinean species belonging to Pseudochirulus. Molecular dates and ancestral reconstructions of geographic provenance combine to suggest that the ancestors of extant New Guinean Pseudochirops spp. and Pseudochirulus spp. dispersed from Australia to New Guinea ∼12.1–6.5 Ma ( Pseudochirops) and ∼6.0–2.4 Ma ( Pseudochirulus). Ancestral state reconstructions support the hypothesis that occupation of high elevations (>3000 m) is a derived feature that evolved on the terminal branch leading to Pseudochirops cupreus, and either evolved in the ancestor of Pseudochirulus forbesi, Pseudochirulus mayeri, and Pseudochirulus caroli, with subsequent loss in P. caroli, or evolved independently in P. mayeri and P. forbesi. Divergence times within the New Guinean Pseudochirops clade are generally coincident with the uplift of the central cordillera and other highlands. Diversification within New Guinean Pseudochirulus occurred in the Plio-Pleistocene after the establishment of the Central Range and other highlands. [ABSTRACT FROM AUTHOR]

The evolution of Australia's distinctive marsupial fauna has long been linked to the onset of continent-wide aridity. However, how this profound climate change event affected the diversification of extant lineages is still hotly debated. Here, we assemble a DNA sequence dataset of Macropodoidea-the clade comprising kangaroos and their relatives-that incorporates a complete mitogenome for the Desert 'rat-kangaroo', Caloprymnus campestris. This enigmatic species went extinct nearly 90 years ago and is known from a handful of museum specimens. Caloprymnus is significant because it was the only macropodoid restricted to extreme desert environments, and therefore calibrates the group's specialisation for increasingly arid conditions. Our robustly supported phylogenies nest Caloprymnus amongst the bettongs Aepyprymnus and Bettongia. Dated ancestral range estimations further reveal that the Caloprymnus-Bettongia lineage originated in nascent xeric settings during the middle to late Miocene, ~ 12 million years ago (Ma), but subsequently radiated into fragmenting mesic habitats after the Pliocene to mid-Pleistocene. This timeframe parallels the ancestral divergences of kangaroos in woodlands and forests, but predates their adaptive dispersal into proliferating dry shrublands and grasslands from the late Miocene to mid-Pleistocene, after ~ 7 Ma. We thus demonstrate that protracted changes in both climate and vegetation likely staged the emergence of modern arid zone macropodoids., (© 2022. The Author(s).)

Erroneous taxonomic attributions in GenBank accessions can mislead phylogenetic inference and appear to be widespread within genera. We investigate the influence of taxonomic misattributions for reconstructing the phylogeny of three-striped dasyures, which include four recognized Myoictis species (Marsupialia: Dasyuridae) that are distributed across New Guinea and nearby islands. Molecular phylogenetic studies that have focused on dasyurids consistently resolve the interrelationships of these small carnivores, grouping M. leucura with M. wavicus, and placing M. wallacei and M. melas as successively deeper divergences from these. Two recent marsupial and mammalian supermatrix phylogenies instead favour an alternative Myoictis topology that is discordant with each of these relationships. We add new nuclear and mitochondrial sequences and employ randomized accession resampling that shows the supermatrix topologies are an artefact of several outdated taxonomic attributions in GenBank. Updating these accessions brings agreement across Myoictis phylogenies with randomly resampled accessions. We encourage authors to update GenBank taxonomic attributions and we argue that an option is needed for flagging accessions that are not demonstrably incorrect, but that provide anomalous results. This would serve both as a caution for future supermatrix construction and to highlight accessions of potentially significant biological interest for further study., (Copyright © 2021 Elsevier Inc. All rights reserved.)