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Ojala-Barbour R.,National Polytechnic School of Ecuador | Pinto C.M.,American Museum of Natural History | Pinto C.M.,City University of New York | Pinto C.M.,Pontifical Catholic University of Ecuador | And 4 more authors.
Journal of Mammalogy | Year: 2013

The 4 known species of northern shrew-opossums, Caenolestes (Paucituberculata: Caenolestidae), are restricted to the northern Andes of South America. Five specimens of a new species of Caenolestes were collected in Sangay National Park on the eastern slopes of the Andes in Ecuador. Review of museum specimens revealed 6 additional specimens of this species, here named Caenolestes sangay. All specimens were collected in cloud forest habitats from 2,050 to 3,500 m above sea level along a recently constructed highway. The new species appears to be uncommon. Inadequate sampling on the eastern slopes of the Andes limits our understanding of the distributional limits of the new species, but it occurs in a region of high endemism. New roads and land conversion threaten mature habitats near the type locality. The new species is medium sized with a narrow antorbital vacuity. It is distinguished from congeners by its large major palatine foramen and a diastema between I4 and C, among other characters. A phylogeny of Caenolestidae based on molecular and morphological characters shows a sister-group relationship between Lestoros and Rhyncholestes and indicates that the new species is likely closest to C. caniventer. © 2013 American Society of Mammalogists. Source

Fikacek M.,National Museum in Prague | Fikacek M.,Charles University | Minoshima Y.N.,Kitakyushu Museum of Natural History and Human History | Newton A.F.,Center for Integrative Research
Annales Zoologici | Year: 2014

The taxonomy and morphology of species related to the genus Andotypus Spangler, 1979 (Coleoptera: Hydrophiloidea: Hydrophilidae: Rygmodinae) are reviewed in detail. Austrotypus gen. nov. is established for A. nothofagi sp. nov. (eastern Australia) and A. peruanus sp. nov. (Peru), both of which share the same morphology of the mouthparts and mesoventrite. The genus Andotypus is found to be endemic to central and sourthern Chile, containing two species: A. ashworthi Spangler, 1979 and A. araucariae sp. nov. Andotypus perezdearcei Moroni, 2000 is found to belong to the genus Dactylosternum Wollaston, 1854 (Hydrophilidae: Sphaeridiinae: Coelostomatini), and is a junior subjective synonym of the introduced species D. abdominale (Fabricius, 1792). Adults of all species of Andotypus and Austrotypus are (re)described in detail and important characters are illustrated. Larval morphology and head chaetotaxy is described and illustrated in detail for Andotypus ashworthi and Austrotypus nothofagi, revealing differences in head morphology and abdominal tergites which support the separate status of both genera. The taxonomic position of the genera within the Rygmodinae is briefly discussed, but should be corroborated by formal phylogenetic analysis. We hypothesize that the austral disjunct distribution of Austrotypus as well as current distribution of Andotypus are results of the break-up of Gondwana combined with changes of climate in austral South America, Antarctica and Australia during the Cenozoic. Andotypus and Austrotypus represent an independently evolved lineage of dung- and carrion-associated beetles native to the southern temperate zone, and the fact that their larvae largely resemble those of Sphaeridium Fabricius, 1775 suggests that they may represent a partial ecological analogue of the Old World medium-sized coprophilous hydrophilids of the tribe Sphaeridiini. The syntopical co-occurrence of Austrotypus nothofagi with four similarly colored scarabaeoid dung-inhabiting beetles (Onthophagus sydneyensis Blackburn, 1903, O. arrilla Matthews, 1972, Lepanus ustulatus (Lansberge, 1874) and Liparochrus nanus Paulian, 1980) suggests that Austrotypus nothofagi may be a member of a mimetic complex formed by these species. © 2014 Fundacja Natura optima dux. Source

Havstad J.C.,The Field Museum | Assis L.C.S.,Federal University of Minas Gerais | Rieppel O.,Center for Integrative Research
Journal of Experimental Zoology Part B: Molecular and Developmental Evolution | Year: 2015

The relation of homology is generally characterized as an identity relation, or alternatively as a correspondence relation, both of which are transitive. We use the example of the ontogenetic development and evolutionary origin of the gnathostome jaw to discuss identity and transitivity of the homology relation under the transformationist and emergentist paradigms respectively. Token identity and consequent transitivity of homology relations are shown to be requirements that are too strong to allow the origin of genuine evolutionary novelties. We consequently introduce the concept of compositional identity that is grounded in relations prevailing between parts (organs and organ systems) of a whole (organism). We recognize an ontogenetic identity of parts within a whole throughout the sequence of successive developmental stages of those parts: this is an intra-organismal character identity maintained throughout developmental trajectory. Correspondingly, we recognize a phylogenetic identity of homologous parts within two or more organisms of different species: this is an inter-species character identity maintained throughout evolutionary trajectory. These different dimensions of character identity-ontogenetic (through development) and phylogenetic (via shared evolutionary history)-break the transitivity of homology relations. Under the transformationist paradigm, the relation of homology reigns over the entire character (-state) transformation series, and thus encompasses the plesiomorphic as well as the apomorphic condition of form. In contrast, genuine evolutionary novelties originate not through transformation of ancestral characters (-states), but instead through deviating developmental trajectories that result in alternate characters. Under the emergentist paradigm, homology is thus synonymous with synapomorphy. © 2015 The Authors. Source

Nesbitt S.J.,University of Washington | Nesbitt S.J.,Center for Integrative Research | Turner A.H.,State University of New York at Stony Brook | Weinbaum J.C.,Southern Connecticut State University
Earth and Environmental Science Transactions of the Royal Society of Edinburgh | Year: 2013

Ossified skeletal elements within the orbit, such as scleral ossicles, palpebrals, supraorbitals and sesamoids, are widespread across Reptilia, including extant members of Crocodylia, Aves, Squamata and Chelonia. Extant crocodylians lack scleral ossicles, but have a unique palpebral that has recently been shown, through developmental studies, to be an osteoderm in the upper eyelid. Here, we examine the diversity and disparity of the crocodylian palpebral in extant members of Crocodylia and, through the fossil record, trace the origin and evolutionary history of the element throughout Pseudosuchia (all archosaurs more closely related to crocodylians than avians). We show that the crocodylian palpebral originated outside of Crocodylomorpha in early pseudosuchian groups (e.g. Aetosauria, Loricata) and that scleral ossicles are lost in nearly all groups of pseudosuchians, but appear in poposauroids, at least one early crocodylomorph, and some partially or fully marine Crocodyliformes (e.g. thalattosuchians). The morphology and number of palpebrals differs across Crocodyliformes; the presence of two palpebrals is plesiomorphic, but this is reduced to one by Crocodylia. We further recommend the restriction of the term palpebral to the structure in crocodylians and their homologues, but not to the structure in ornithischian dinosaurs. © 2013 The Royal Society of Edinburgh. Source

Cisneros L.M.,University of Connecticut | Burgio K.R.,University of Connecticut | Dreiss L.M.,University of Connecticut | Klingbeil B.T.,University of Connecticut | And 3 more authors.
Journal of Animal Ecology | Year: 2014

Research concerning spatial dynamics of biodiversity generally has been limited to considerations of the taxonomic dimension, which is insensitive to interspecific variation in ecological or evolutionary characteristics that play important roles in species assembly and provide linkages to ecosystem services. Consequently, the assumption that the taxonomic dimension is a good surrogate for other dimensions remains unconfirmed. We assessed variation in taxonomic (species richness) as well as phylogenetic and functional (Rao's quadratic entropy, a measurement of dispersion) dimensions of bat biodiversity along an elevational gradient in the Manu Biosphere Reserve of Peru. Phylogenetic dispersion was based on relatedness of species derived from a mammalian supertree. Functional dispersion was estimated separately for each of six functional components that reflect particular niche axes (e.g. diet, foraging strategy, body size) and for all functional components combined. Species richness declined nonlinearly with elevation, whereas phylogenetic dispersion and functional dispersion based on all functional components were not significantly associated with elevation (orthogonal polynomial regression). Moreover, considerable heterogeneity in the form of elevational relationships existed among functional components. After accounting for variation in species richness, dispersion of phylogenetic, diet and foraging strategy attributes were significantly greater than expected at high elevations, whereas dispersion of body size was significantly less than expected at high elevations. Species richness was a poor surrogate for phylogenetic or functional dispersion. Functional dispersion based on multiple components obscured patterns detected by particular components and hindered identification of mechanistic explanations for elevational variation in biodiversity. Variation in phylogenetic dispersion effectively captured the composite variation represented by all functional components, suggesting a phylogenetic signal in functional attributes. Mechanisms that give rise to variation in richness do not fully account for variation in phylogenetic or functional characteristics of assemblages. Greater than expected phylogenetic, diet and foraging strategy dispersion at high elevations were associated with the loss of phylogenetically or functionally redundant species, suggesting that increasing interspecific competition with decreasing productivity resulted in competitive exclusion. In contrast, low dispersion of size attributes at high elevations suggests the importance of abiotic filtering that favours small-sized species that can more easily enter torpor. © 2014 British Ecological Society. Source

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