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Apomys, a Philippine endemic genus of forest mice, occurs throughout most oceanic portions of the archipelago and is its most speciose mammal genus, with 18 species currently recognized. Recent extensive surveys of mammals on Mindoro Island have produced specimens that document the presence of three genetically and morphologically distinct candidate species of Apomys (subgenus Megapomys) previously unknown. These three, plus one previously described relative from Mindoro, constitute a clade of well-supported, reciprocally monophyletic units based on cytochrome b sequence data, all of which are strongly supported using BPP species delimitation. Data from three nuclear genes show less divergence, but species delimitation analyses are consistent with results from cytochrome b. These four taxa are easily diagnosed on the basis of pelage and cranial morphology. Each of the four species occurs allopatrically, though two occur along a single elevational gradient. In this paper, we formally describe the three new species. We estimate that the common ancestor of the four species arrived on Mindoro from Luzon roughly 4.7 Ma, with initial diversification beginning roughly 2.7 Ma, and increasing to the current four species about 1.3 Ma. The three new species increase the number of mammals currently recognized as endemics on Mindoro from nine to twelve. This is a remarkably high number of endemic mammals from an island of its size, and reflects Mindoro’s status as a geologically old island permanently isolated from other oceanic islands in the Philippines by deep water, while also corroborating Mindoro as the smallest island within which endemic speciation by small mammals is known to have occurred.   

Abstract The “small-eared” species group of Urocitellus ground squirrels (Sciuridae: Xerinae: Marmotini) is endemic to the Great Basin, United States, and surrounding cold desert ecosystems. Most specific and subspecific lineages in this group occupy narrow geographic ranges, and some are of significant conservation concern; despite this, current taxonomy remains largely based on karyotypic or subtle pelage and morphological characteristics. Here, we leverage 2 multilocus DNA sequence data sets and apply formal species delimitation tests alongside morphometric comparisons to demonstrate that the most widespread small-eared species (U. mollis Kennicott, 1863 sensu lato; Piute Ground Squirrel) is comprised of 2 nonsister and deeply divergent lineages. The 2 lineages are geographically separated by the east-west flowing Snake River in southern Idaho, with no sites of sympatry currently known. Based on robust support across the nuclear genome, we elevate populations previously attributed to U. mollis from north of the Snake River to species status under the name Urocitellus idahoensis (Merriam 1913) and propose the common name “Snake River Plains Ground Squirrel” for this taxon. We delimit 2 subspecies within U. idahoensis; U. i. idahoensis (Merriam 1913) in western Idaho and U. i. artemesiae (Merriam 1913) in eastern Idaho. Urocitellus idahoensis is endemic to Idaho and has a maximal range area of roughly 29,700 km2 spanning 22 counties but occurs discontinuously across this area. Our work substantially expands knowledge of ground squirrel diversity in the northern Great Basin and Columbia Plateau and highlights the difficulty in delimiting aridland mammals whose morphological attributes are highly conserved. 

Abstract Natural history collections are repositories of biodiversity specimens that provide critical infrastructure for studies of mammals. Over the past 3 decades, digitization of collections has opened up the temporal and spatial properties of specimens, stimulating new data sharing, use, and training across the biodiversity sciences. These digital records are the cornerstones of an “extended specimen network,” in which the diverse data derived from specimens become digital, linked, and openly accessible for science and policy. However, still missing from most digital occurrences of mammals are their morphological, reproductive, and life-history traits. Unlocking this information will advance mammalogy, establish richer faunal baselines in an era of rapid environmental change, and contextualize other types of specimen-derived information toward new knowledge and discovery. Here, we present the Ranges Digitization Network (Ranges), a community effort to digitize specimen-level traits from all terrestrial mammals of western North America, append them to digital records, publish them openly in community repositories, and make them interoperable with complimentary data streams. Ranges is a consortium of 23 institutions with an initial focus on non-marine mammal species (both native and introduced) occurring in western Canada, the western United States, and Mexico. The project will establish trait data standards and informatics workflows that can be extended to other regions, taxa, and traits. Reconnecting mammalogists, museum professionals, and researchers for a new era of collections digitization will catalyze advances in mammalogy and create a community-curated trait resource for training and engagement with global conservation initiatives.