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Species loss in fragile insular communities can alter the composition and stability of local assemblages. Climate change or anthropogenic pressures are sometimes attributed to the loss of Caribbean bats, but other factors are elusive to document. We studied time-scaled changes in bat assemblage composition from a palaeontological excavation in Cueva Matos, Puerto Rico. Over 800 individual fossils were identified to species, and charcoal was used to develop an AMS¹⁴C chronology. Although three bat species live in the cave today, fossils comprise 10 species. These included five extirpated species from the cave and three no longer present on the island. Losses centred around 2460–4470 kya. Notably, we document the first record ofMormoops megalophyllaas extirpated from Puerto Rico. Nearly 90% of the extirpated bats in Cueva Matos prefer to roost in hot caves where temperatures may reach 40℃. However, these temperatures are currently not held in any cave chamber. Our findings suggest that structural changes in the cave resulted in the loss of heat traps and likely led to a sudden shift in the bat assemblage composition at this cave, which is now void of hot cave specialist bats. 

Neurocordulia, commonly called shadowdragons, are crepuscular dragonflies, flying mainly at dusk. The genus comprises seven species, which occur across the eastern part of Canada and the United States. Here, we used targeted enrichment probes to sequence ~1000 loci for all specimens of each species, allowing for the first phylogenetic assessment of the genus. Additionally, we collected individuals of N. yamaskanensis from a population in Ontario, Canada, and used whole genome resequencing to estimate population structure. Beyond broadly reconstructing the phylogeny of Neurocordulia, we provided a comprehensive bibliography review of past research on the genus, a key to the species, and distribution models for each species. 

ABSTRACT AimThe Indo‐Australian Archipelago (IAA) is one of the most geologically complex and species‐rich regions on Earth. However, our knowledge of the geological processes and dispersal mechanisms that generate archipelago‐wide distributions across the IAA is limited to a few vertebrate groups and often solely attributed to Plio‐Pleistocene sea‐level fluctuations. In this study, we use phylogenomics‐based analyses to investigate two speciose and closely related genera of snakes,LycodonandStegonotus(Serpentes: Colubridae), which are widely distributed across the IAA to identify which biogeographic and environmental processes have shaped snake diversity in this region. LocationSouth Asia and the Indo‐Australian Archipelago (Indochina, Sundaland, Philippines, Wallacea, Australasia). TaxonSnakes (Colubridae:Lycodon, Stegonotus). MethodsWe inferred a phylogeny using a genomic dataset consisting of ultraconserved elements, anchored hybrid enrichment loci, and protein‐coding genes (~5400 nuclear loci) from 38 species (154 samples) ofLycodonandStegonotus. We used ancestral range estimation analysis to identify dispersal patterns across the IAA. Additionally, we implemented ensemble species distribution models to identify potential hotspots ofLycodonandStegonotusspecies richness and determined the environmental influence on geographic distributions and species diversity. ResultsWe find that these snakes comprise six deeply divergent lineages (genera) that initially originated in Mainland Southeast Asia during the Oligocene. Diversification of these lineages is influenced not by Plio‐Pleistocene sea‐level fluctuations but by multiple historical processes, including in situ diversification, island hopping, long‐distance rafting, possible microcontinental block drifting, Cenozoic land bridge migrations and founder events. The species distribution models do not consistently estimate lower or higher species richness in any particular region within the IAA, but precipitation overall is considered an important factor in estimated species richness. Main ConclusionAlthough Plio‐Pleistocene sea‐level fluctuations are notorious species pump diversification paradigms in the IAA, multiple and more ancient geological processes and environmental factors contributed to current diversity levels and distributions. Our approach expands future investigations of alternative hypotheses of biodiversity sources in the IAA and greatly expands the diversity of causal mechanisms for discussions of terrestrial Southeast Asian biodiversity beyond dispersal versus vicariance hypotheses. 

Abstract Species that are geographically widespread may exist across environmentally heterogeneous landscapes that could influence patterns of occupation and phylogeographic structure. Previous studies have suggested that geographic range size should be positively correlated with niche breadth, allowing widespread species to sustain viable populations over diverse environmental gradients. We examined the congruence of phenotypic and phylogenetic divergence with the environmental factors that help maintain species level diversity in the geographically widespread hoary bats ( Lasiurus cinereus sensu lato) across their distribution. Genetic sequences were analyzed using multiple phylogenetic and species delimitation methods, and phenotypic data were analyzed using supervised and unsupervised machine learning approaches. Spatial data from environmental, geographic, and topographic features were analyzed in a multiple regression analysis to determine their relative effect on phenotypic diversity. Ecological niches of each hoary bat species were examined in environmental space to quantify niche overlap, equivalency, and the magnitude of niche differentiation. Phylogenetic and species delimitation analyses support existence of three geographically structured species of hoary bat, each of which is phenotypically distinct. However, the Hawaiian hoary bat is morphologically more similar to the South American species than to the North American species despite a closer phylogenetic relationship to the latter. Multiple regression and niche analyses revealed higher environmental similarities between the South American and Hawaiian species. Hoary bats thus exhibit a pattern of phenotypic variation that disagrees with well-supported genetic divergences, instead indicating phenotypic convergence driven by similar environmental features and relatively conserved niches occupied in tropical latitudes. 

Abstract Divergence dating analyses in systematics provide a framework to develop and test biogeographic hypotheses regarding speciation. However, as molecular datasets grow from multilocus to genomic, sample sizes decrease due to computational burdens, and the testing of fine-scale biogeographic hypotheses becomes difficult. In this study, we use coalescent demographic models to investigate the diversification of poorly known rice paddy snakes from Southeast Asia (Homalopsidae:Hypsiscopus), which have conflicting dates of origin based on previous studies. We use coalescent modeling to test the hypothesis thatHypsiscopusdiversified 2.5 mya during the Khorat Plateau uplift in Thailand. Additionally, we use ecological niche analyses to identify potential differences in the niche space of the two most widely distributed species in the past and present. Our results suggestHypsiscopusdiversified ~ 2.4 mya, supporting that the Khorat Plateau may have initiated the diversification of rice paddy snakes. We also find significant niche differentiation and shifts between species ofHypsiscopus, indicating that environmental differences may have sustained differentiation of this genus after the Khorat Plateau uplift. Our study expands on the diversification history of snakes in Southeast Asia, and highlights how results from smaller multilocus datasets can be useful in developing and testing biogeographic hypotheses alongside genomic datasets.