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The ectotympanic, malleus and incus of the developing mammalian middle ear (ME) are initially attached to the dentary via Meckel's cartilage, betraying their origins from the primary jaw joint of land vertebrates. This recapitulation has prompted mostly unquantified suggestions that several suspected-but similarly unquantified-key evolutionary transformations leading to the mammalian ME are recapitulated in development, through negative allometry and posterior/medial displacement of ME bones relative to the jaw joint. Here we show, using mCT reconstructions, that neither allometric nor topological change is quantifiable in the pre-detachment ME development of six marsupials and two monotremes. Also, differential ME positioning in the two monotreme species is not recapitulated. This challenges the developmental prerequisites of widely cited evolutionary scenarios of definitive mammalian middle ear (DMME) evolution, highlighting the requirement for further fossil evidence to test these hypotheses. Possible association between rear molar eruption, full ME ossification and ME detachment in marsupials suggests functional divergence between dentary and ME as a trigger for developmental, and possibly also evolutionary, ME detachment. The stable positioning of the dentary and ME supports suggestions that a 'partial mammalian middle ear' as found in many mammaliaforms-probably with a cartilaginous Meckel's cartilage-represents the only developmentally plausible evolutionary DMME precursor.

: In spite of previous reviews, there is still no consensus on the information associated to the richness of the genus Coendou in Colombia. To clarify some issues concerning the distribution and the taxonomic identity of the species of Coendou in the country, we reviewed specimens from five natural history collections. We introduce the first record of Coendou ichillus from the Orinoco river basin of the country, extending the distribution of the species by more than 600 km to the north from previous known localities in Ecuador and Peru. Additionally, we present new records of C. pruinosus and C. quichua from the Amazonia and inter-Andean valleys, respectively. Only one skull presents the diagnostic characters of C . bicolor ; thus, previous records of this species for the country were based on misidentifications. Coendou is distributed in seven of the nine geographic provinces of Colombia. Coendou prehensilis was found in five provinces and is expected to be present in the Amazonia, whereas C. pruinosus was documented in three provinces (North Andean, Orinoco and Guyana). The rest of the species of Coendou were distributed in one or two provinces. The richest provinces were North Andean and Orinoco with six and four Coendou species, respectively. The elevational ranges of C. prehensilis and C. pruinosus are revised to 0 -1975 and 90 -2200 m, respectively.

Debido al avance en el desarrollo de investigaciones de diversa índole que involucran mamíferos, cada año se reportan cambios en la riqueza de especies registradas en el territorio nacional. Un esfuerzo notable encaminado a actualizar el conocimiento de este grupo en el país señaló la presencia de 492 especies para el año 2013 (Solari et al. 2013). Este número se incrementó a 500 especies para el año 2014, a partir de revisiones sistemáticas o adiciones de nuevas localidades de distribución para varias especies neotropicales (Ramírez-Chaves & Suárez-Castro 2014) y en esta revisión se aumenta el número de especies a 518 para el país. El incremento ha sido mayor para murciélagos (orden Chiroptera), grupo que actualmente cuenta con el número más alto de especies de mamíferos registradas en Colombia (205 especies). Sin embargo, el uso de nuevas técnicas y exploraciones de campo realizadas por diferentes investigadores han generado una gran cantidad de conocimiento para otros grupos, por lo que es necesario sintetizar la información de manera constante para que estédisponible a todos aquellos involucrados en estudiar y conservar la biodiversidad del país. Con el fin de actualizar el número de especies de mamíferos registradas en el territorio nacional, presentamos una valoración y actualización con los cambios recientes para Colombia durante los últimos meses.

Vampyressa melissa is a poorly known phyllostomid bat listed as vulnerable by the Inter¬ national Union for Conservation of Nature (IUCN). Since its description in 1926, fewer than 40 V. melissa have been reported in the literature, and less than half of these may have been correctly identified. During revisionary studies of Vampyressa, we uncovered two previously unrecognized species related to V. melissa, all associated with higher elevation habitats (>1400 m), one from the Andes of Colombia (Vampyressa sinchi, new species) and the other from western Panama (Vampyressa elisabethae, new species) revealing that V. melissa, as traditionally defined, is a composite of at least three species. In this paper, we provide a restricted diagnosis for the genus Vampyressa, an emended diagnosis of V. melissa, and descriptions of the two new species. The separation of these frugivorous bats, previously identified as V. melissa, into three isolated upper-elevation species, each having restricted distributions further highlights their fragile conservation status.

Introduction: Genetic data hypothetically place the origin of the most recent common ancestor of the subfamily Emballonurinae in Africa, suggesting a dispersal event from Africa to South America during the Oligocene (30 Ma), and a subsequent allopatric radiation in the New World. Emballonurid genera exist in Central America where, to date, only one event of diversification has been documented for Balantiopteryx before the completion of the Isthmus of Panama land connection in the Pliocene. Methods: Emballonurid bats constitutes an important element of the bat fauna in Colombia. Herein, museum voucher specimens were used as primary source to generate a checklist of emballonurid bats from Colombia. In addition, selected museum voucher specimens were analyzed to verify their identifications. The checklist is accompanied by references as well as models of potential distribution for each Colombian emballonurid species. These distribution maps were used to investigate the affinities, in species composition, among Colombian ecoregions as outlined by Hernández-Camacho et al. (1992), and to determine emballonurid richness distribution in Colombia and the relationship between environmental variables and patterns of species richness in this group of bats in the country. Results: We report 16 confirmed emballonurid bat species for Colombia and three species potentially present in the country, for a total of 19 species representing the eight recognized Neotropical emballonurid genera. At 16 known species, Colombia has the second greatest number of Neotropical emballonurid bats after Brazil (17 spp.). Discussion and conclusion: The checklist presented herein is accompanied by 11 taxonomic and distributional comments explaining recent changes in taxonomy, species distribution rearrangements, as well as clarifications and a refinement of the previous records for Colombia. In addition, Geographic Information System (GIS) models of potential distribution were created for all confirmed species in Colombia, and species richness patterns were analyzed. Finally, in a Parsimony Analysis of Endemism was performed for Colombian emballonurids we found that diversity within this group of bats in geographically subdivided in Colombia into four main regions including: The Biogeographic Chocó; the Magdalena Valley; The Orinoquia; and the Guianan-Amazon region.

The Quichua porcupine (Coendou quichua) is a neotropical rodent with uncertain taxonomic and conservation status. Two Quichua porcupines with severe hyperkeratosis and alopecia were found in the Magdalena River Basin of Colombia. Sarcoptes scabiei, the mite causing mange, a disease carried mainly by domestic animals, was confirmed via parasitological and molecular methods. This is the first report of mange in neotropical porcupines to date. The population-level impact of mange in Coendou spp., related mammals and predators in Colombia might represent a threat and needs further investigation.

BackgroundThe minute, finely-tuned ear ossicles of mammals arose through a spectacular evolutionary transformation from their origins as a load-bearing jaw joint. This involved detachment from the postdentary trough of the mandible, and final separation from the dentary through resorption of Meckel’s cartilage. Recent parsimony analyses of modern and fossil mammals imply up to seven independent postdentary trough losses or even reversals, which is unexpected given the complexity of these transformations. Here we employ the first model-based, probabilistic analysis of the evolution of the definitive mammalian middle ear, supported by virtual 3D erosion simulations to assess for potential fossil preservation artifacts.ResultsOur results support a simple, biologically plausible scenario without reversals. The middle ear bones detach from the postdentary trough only twice among mammals, once each in the ancestors of therians and monotremes. Disappearance of Meckel’s cartilage occurred independently in numerous lineages from the Late Jurassic to the Late Cretaceous. This final separation is recapitulated during early development of extant mammals, while the earlier-occurring disappearance of a postdentary trough is not.ConclusionsOur results therefore suggest a developmentally congruent and directional two-step scenario, in which the parallel uncoupling of the auditory and feeding systems in northern and southern hemisphere mammals underpinned further specialization in both lineages. Until ~168 Ma, all known mammals retained attached middle ear bones, yet all groups that diversified from ~163 Ma onwards had lost the postdentary trough, emphasizing the adaptive significance of this transformation.Electronic supplementary materialThe online version of this article (doi:10.1186/s12983-016-0171-z) contains supplementary material, which is available to authorized users.