Aerodynamic reconstruction of the primitive fossil bat Onychonycteris finneyi (Mammalia: Chiroptera)

Bats are the only mammals capable of powered flight. One of the oldest bats known from a complete skeleton is Onychonycteris finneyi from the Early Eocene (Green River Formation, Wyoming, 52.5 Ma). Estimated to weigh approximately 40 g, Onychonycteris exhibits the most primitive combination of characters thus far known for bats. Here, we reconstructed the aerofoil of the two known specimens, calculated basic aerodynamic variables and compared them with those of extant bats and gliding mammals. Onychonycteris appears in the edges of the morphospace for bats, underscoring the primitive conformation of its flight apparatus. Low aerodynamic efficiency is inferred for this extinct species as compared to any extant bat. When we estimated aerofoil variables in a model of Onychonycteris excluding the handwing, it closely approached the morphospace of extant gliding mammals. Addition of a handwing to the model lacking this structure results in a 2.3-fold increase in aspect ratio and a 28% decrease in wing loading, thus greatly enhancing aerodynamics. In the context of these models, the rapid evolution of the chiropteran handwing via genetically mediated developmental changes appears to have been a key transformation in the hypothesized transition from gliding to flapping in early bats.Fil: Amador, Lucila Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Simmons, Nancy B.. American Museum of Natural History; Estados UnidosFil: Giannini, Norberto Pedro. American Museum of Natural History; Estados Unido

Systematics of Vampyrodes.

35 p. : ill. (some col.), map ; 26 cm. "April 20, 2011."The Neotropical bat genus Vampyrodes (Chiroptera: Phyllostomidae: Stenodermatinae) is widely distributed from southern Mexico to southeastern Brazil. Long thought to be monotypic, V. caraccioli Thomas, 1889, was recognized by previous authors as including two subspecies with the nominate form inhabiting South America south and east of the Andes, and another subspecies, V. c. major Allen, 1908, occurring west and north of the Andes. Reexamination of these forms using molecular and morphological methods supports recognition of these lineages as distinct at the species level. We here provide amended descriptions and diagnoses for these taxa. We also report for the first time an example of perikymata (incremental growth lines that appear on the surface of dental enamel as a series of grooves) in Chiroptera. Presence of distinct perikymata is a synapomorphy of the genus Vampyrodes

Enhanced monography in a collaboratively evolved hub for systematic biology

No abstract available

New species of Hsunycteris.

26 pages : illustrations (some color), map ; 26 cm.A new species of the nectarivorous bat genus Hsunycteris is described from lowland Amazonian forest in northeastern Peru. The new species, H. dashe, can be distinguished from other congeners by its larger size; V-shaped array of dermal chin papillae separated by a wide basal cleft; metacarpal V longer than metacarpal IV; broad rostrum; lateral margin of infraorbital foramen not projecting beyond rostral outline in dorsal view; well-developed sphenoidal crest; large outer upper incisors; weakly developed lingual cusp on P5; and well-developed, labially oriented M1 parastyle. A phylogenetic analysis of cytochrome-b sequence data indicates that H. dashe is sister to a clade that includes all other species of the genus including H. cadenai, H. pattoni, and a paraphyletic H. thomasi. We provide a key based on craniodental and external characters of all four known species of Hsunycteris

Livestock abundance predicts vampire bat demography, immune profiles, and bacterial infection risk

Human activities create novel food resources that can alter wildlife–pathogen interactions. If resources amplify or dampen, pathogen transmission probably depends on both host ecology and pathogen biology, but studies that measure responses to provisioning across both scales are rare. We tested these relationships with a 4-year study of 369 common vampire bats across 10 sites in Peru and Belize that differ in the abundance of livestock, an important anthropogenic food source. We quantified innate and adaptive immunity from bats and assessed infection with two common bacteria. We predicted that abundant livestock could reduce starvation and foraging effort, allowing for greater investments in immunity. Bats from high-livestock sites had higher microbicidal activity and proportions of neutrophils but lower immunoglobulin G and proportions of lymphocytes, suggesting more investment in innate relative to adaptive immunity and either greater chronic stress or pathogen exposure. This relationship was most pronounced in reproductive bats, which were also more common in high-livestock sites, suggesting feedbacks between demographic correlates of provisioning and immunity. Infection with both Bartonella and haemoplasmas were correlated with similar immune profiles, and both pathogens tended to be less prevalent in high-livestock sites, although effects were weaker for haemoplasmas. These differing responses to provisioning might therefore reflect distinct transmission processes. Predicting how provisioning alters host–pathogen interactions requires considering how both within-host processes and transmission modes respond to resource shifts

Sesamoid elements in bats.

38 pages : illustrations (chiefly color) ; 26 cm.Sesamoids are skeletal elements found within a tendon or ligament as it passes around a joint or bony prominence. Here we review the distribution of sesamoids in bats, the only mammals capable of powered flight. Our survey included bat species representing most extant families as well as two key Eocene fossil bats in which sesamoids are exquisitely preserved, Onychonycteris finneyi and Icaronycteris index. We identified 46 separate sesamoid elements (or sets of elements) from dissections of selected bat taxa, with no more than 23 of these present in any given species. Among the sesamoids identified in our survey, 12 have not previously been described in bats. We also identified seven sesamoids previously described in the literature that are not present in our sample of species. No sesamoids were found to be exclusive to the fossil taxa in our study; all the sesamoids observed in Onychonycteris and Icaronycteris have apparent homologs among extant species. We mapped the presence/absence of the 46 sesamoids onto a bat phylogeny. Based on these optimizations, we discuss homology issues and evolutionary history of some of the most taxonomically widespread sesamoids. Functional inferences regarding some sesamoids can be made based on what is known about bat musculoskeletal morphology, although further biomechanical studies are required to test the hypotheses proposed here. Sesamoids will continue to be a source of interesting insights about the evolution of bats and their unique locomotor abilities