Huemacaspis (Trilobita, Kerfornellinae) from the Late Ordovician of the Argentine Cordillera Oriental

The trilobite genus Huemacaspis P?IBYL and VANěK, 1980 is redescribed from well-preserved material from the Santa Gertrudis Formation (early Caradoc), Argentine Cordillera Oriental. The new species H. gallinatoensis is described and figured. Huemacaspis is widely distributed in the southern part of the Central Andean basin during the early Caradoc and it is a key taxon for the correlation of different units from the Cordillera Oriental and Sierras Subandinas of Argentina and the Cordillera Oriental of Bolivia. This taxon is one of the few records of trilobites of early Caradoc age found in the shallow shelf environments of southwestern Gondwana. Huemacaspis is accommodated within the Kerfornellinae, a subfamily otherwise known from southern Central Europe and northern Africa. The trilobite fauna from the early Caradoc of the Central Andean basin suggests a faunal exchange with the latter regions indicating the persistence of a broadly similar biogeographic pattern to that documented in earlier Ordovician times.     

A new species of Elatine (Elatinaceae) from the Colombian páramos in the northern Andes

Elatine paramoana, a new species from the high Andean region of the Cordillera Oriental in Colombia, is described, illustrated, and compared to its nearest relatives,E. ecuadoriensis andE. fassettiana. Notes on morphological variation and general ecology and a key to the central and northern Andes species are also given.     

Three new species of Euathlus Ausserer, 1875 (Araneae,Theraphosidae) from Argentina

ABSTRACT

Euathlus

Ausserer, 1875 is a South American genus of spiders of the family Theraphosidae known from Chile and Argentina. Three new species from Argentina: Euathlus mauryi sp. n. (from San Juan province), Euathlus grismadoi sp. n. (from La Rioja province), and Euathlus pampa sp. n. (from Salta province) are described here. New records of the previous species Euathlus diamante and Euathlus tenebrarum are contributed. The distribution of these new species expands the geographical distribution of the genus along the Andean hills, with Salta province as the northernmost record of the genus. A key is provided for identification of Euathlus species as well as a map with all the records in Argentina.     

Axinaea fernando‐cabiesii and A. reginae spp. nov. (Melastomataceae) from upper Amazonia of Peru,with notes on the conservation status of A. flava

Two new Peruvian species of Axinaea (Melastomataceae) are described. Axinaea francisco‐cabiesii and Axinaea reginae are small trees, endemic to the cloud forest zone in the northern Andean region of Peru. The border region of Peru and Ecuador is one of the Earth's most biologically diverse areas. The Huancabamba depression of the central Andean Cordillera allows for dispersal of flora and fauna between the Amazon Basin and the Pacific lowlands. Additionally, the region is characterized by a fast transition between the humid mountain forests of the northern Andes and the dry, deciduous forests of the northern Peruvian lowlands, making it a hotspot for endemic species. Field observations indicate that both new Axinaea species have small population sizes, occurring in a very restricted habitat. Axinaea flava was described only a few years ago from the cloud forest – paramo transition zone in southernmost Ecuador between 3400 and 3800 m a.s.l. This small tree is the only yellow‐flowered species of the genus. The original assessment counted about 100 individuals. In the last decade, livestock grazing and widespread burning have intensified in the region, and a new assessment yielded only 10 individuals, four of which were damaged by fire. This puts the species in danger of extinction. We encourage search for other populations in southern Ecuador and northern Peru.     

Pleistocene refugia and recolonization routes in the southern Andes: insights from Hypochaeris palustris (Asteraceae, Lactuceae)

Hypochaeris palustris (Phil.) De Wild. is a species growing in the southern Andean chain. To elucidate potential Pleistocene refugia and recolonization routes in the southern Andes, we analysed amplified fragment length polymorphisms (AFLPs) in 206 individuals in 21 populations of H. palustris from the coastal Cordillera, the central, northern, and eastern ranges of the southern Andes, and Patagonia. Populations from the coastal Cordillera harboured more private AFLP fragments, and exhibited a higher frequency of polymorphic fragments as well as higher Shannon diversity than all other areas investigated. The comparison among pooled AFLP profiles of each region revealed that the central Andean ranges shared most fragments with populations from the margins of the distributional area in the Andes, in the N, E, and S (Patagonia). Phenetic analysis indicated close relationships among populations of the central ranges. Populations of the coastal Cordillera were shown to be highly differentiated from the Andean populations. It is very likely therefore that (1) H. palustris recolonized the central ranges of the southern Andes from nearby refugia, possibly unglaciated areas N, E, and/or S of its present distributional area; (2) the postglacial spread of H. palustris in the central ranges of the southern Andes occurred rapidly; and (3) the coastal Cordillera served as a refugium for H. palustris, but these populations did not contribute to the recolonization of the central Andean ranges.     

Stratigraphical distribution of the Ordovician graptolite Azygograptus Nicholson & Lapworth in the Central Andean Basin (northwestern Argentina and southern Bolivia)

We analyzed new occurrences of Azygograptus lapworthi from the Cordillera Oriental, Argentina. The bearer sandstones levels, corresponding to the Acoite Formation, are overlying the deposits, in which the Didymograptellus bifidus Biozone (Lower Ordovician, upper Floian, Fl3) was previously recognized, and are overlain by younger pelitic levels yielding Xiphograptus lofuensis (Middle Ordovician, early Dapingian, Dp2). Previous records from the Central Andean Basin are also reviewed in detail and accurately correlated, allowing us to conclude that the Azygograptus lapworthi Biozone corresponds to the Middle Ordovician (lower Dapingian, Dp1). This biostratigraphic framework documents that the transition between the Lower and Middle Ordovician deposits occurs in the uppermost levels of the Acoite Formation in the Argentine Cordillera Oriental. It is additionally integrated with up to date conodont records to establish a high-resolution regional correlation, with equivalent deposits from the Puna of northwestern Argentina and Cordillera Oriental of Bolivia, and to discuss new insights for global correlation.     

Revision ofDoniophyton (Compositae, Barnadesioideae)

This revision describes, illustrates and documents morphological variation inDoniophyton (Compositae, Barnadesioideae), restricted to Argentina and Chile. Two species are recognized,D. anomalum andD. weddellii (sp. nova), possessing distinct morphological and chromosomal features, elevational tolerances, and nearly allopatric distributions.Doniophyton weddellii occurs primarily in central to northern Andean Chile and Argentina from 1900–4000 m a. s. l.;D. anomalum is found principally in centralwestern Argentina and south into Patagonia at 0–1800 m a. s. l. Close relationship exists withChuquiraga of subfam.Barnadesioideae. It is hypothesized thatDoniophyton evolved out ofChuquiraga in the high central Andes between Chile and Argentina. It is suggested thatD. weddellii differentiated first, correlating with an aneuploid chromosomal decrease from n = 27 (inChuquiraga) to n = 25. Further evolution and chromosomal decrease to n = 24 resulted inD. anomalum, with accompanying migration into southern Andes and Patagonia. Nomenclatural changes result from examination of protologues and type specimens:Doniophyton anomalum replaces the commonly used nameD. patagonicum, and a new species,D. weddellii, is described for the taxon masquerading under the routinely used superfluous nameD. andicola. This paper is dedicated with admiration and respect to emer. Univ.-Prof. DrFriedrich Ehrendorfer, one of the world's outstanding plant systematists, and a leading scientist and administrator of the Institute of Botany of the University of Vienna     

Phytogeographical relations of the Andean dry valleys of Bolivia

Aim The objective of this study is to examine the phytogeographical affinities of the Andean dry valleys of Bolivia in order to contribute to a better understanding of the Andean dry flora's distribution, origin and diversity. Particular emphasis is given to the analysis of the floristic connections of this flora with more austral parts of South America. Location The dry valleys of Bolivia are located in the Andes of the southern half of the country, at elevations between 1300 and 3200 m. Methods An extensive floristic list compiled by the author to evaluate plant diversity in these Andean regions was used as the base for this study. To accomplish this, all recorded genera and species were assigned, respectively, to 11 and 12 phytogeographical elements established previously by the author. Two phytogeographical spectra were thus obtained and analysed. Results At the genus level, the Andean dry valleys of Bolivia are clearly dominated by genera that have widespread distributions (cosmoplitan and subtropical genera). Many of these reached the Andes from the lowland region of the Chaco. At species level, Andean elements constitute more than 60% of the species total, most of which are restricted to the central‐southern Andes. This suggests that Chaco‐related and Andean genera had considerable levels of speciation in these valleys. Many genera and more than half the species have their northernmost distribution in the dry valleys of Bolivia, thereby underlining strong relationships with central‐southern South America (mainly Argentina, Paraguay and southern Brazil). The data supports the belief of the existence, in central‐southern Peru, of a floristic disjunction in dry to arid environments that separates a tropical dry flora north of this limit from a dry subtropical/warm temperate flora south of it. Main conclusions The Andean dry valleys of Bolivia are diverse plant communities with high levels of endemism (c. 18% of the species). The species of this region are more related to those present in central‐southern South America than to the flora of northern South America that ranges southwards to Peru. Many of the species have restricted distributions in the dry Andes of Bolivia and Argentina, and many genera of these dry valleys have their northernmost distribution in Bolivia/southern Peru, too. The data point to high levels of speciation also in the central Andes.     

Two new species of Aa (Orchidaceae,Spiranthoideae) from Colombia

Two new species of the Andean genus Aa (Orchidaceae, Spiranthoideae) are described: Aa lozanoi Szlach. and S. Nowak, and Aa figueroi Szlach. and S. Nowak. They are restricted in distribution mainly to Cordillera Oriental in the department of Cundinamarca, however, A. lozanoi was also collected in Cordillera Central and A. figueroi in Sierra Nevada de Santa Marta, in northern part of Colombia. Each species is described and illustrated, detailed habitat and distribution data are provided. A distribution map of the new species is presented. A dichotomous key for determination of the Colombian species of Aa is provided. Brief discussion about the most important threats for plants in Andes is presented.     

New insights into the genetic structure of Araucaria araucana forests based on molecular and historic evidences

The conservation of genetic resources is a prerequisite for the maintenance of long-lived forest species. Araucaria araucana (Mol.) K. Koch is one of the oldest conifers in South America and a representative symbol of Chilean forest due to its endemicity and longevity. The aim of this study was to evaluate the genetic structure of the current A. araucana populations in Chile, to verify the possible genetic divergence between Coastal and Andean populations and to assess whether bottleneck events have influenced habitat fragmentation and threaten the genetic resources and evolutionary potential of the species. Twelve natural populations, nine from the Andes Cordillera and three from the Coast Cordillera were analysed by means of eight genomic microsatellite markers developed in A. araucana. Results of analysis of molecular variance (AMOVA) highlighted significant differentiation between Coastal and Andean populations (16 %; P?=?0.004), detecting one significant barrier that separated populations from both Cordilleras as maximally differentiated areas. At local scale, both ranges revealed significant inter-population differentiation, with higher values for Coastal populations compared with Andean populations. These results suggested the presence of four gene pools (three in the Andes and one in the Coast Cordilleras) and one population (VIL) in the Coast Cordillera that differed to the rest. The differentiation between the Andean and Coastal populations may provide important baseline data that should allow further studies of landscape genetics in the species and that can contribute to develop conservation strategies for its genetic resources.     

Population status of Andean Condors in central and southern Bolivia

Andean Condors (Vultur gryphus) are a Near Threatened species that was formerly distributed along the entire length of the Andes from western Venezuela to Tierra del Fuego. Populations have been severely reduced north of Peru, but several thousand Andean Condors still exist in the southern portion of their range in Argentina and Chile. Little is known, however, about the size of the Andean Condor population in the central part of their range in Peru and Bolivia. From June to September 2012, we used feeding stations to attract Andean Condors and estimate the size and structure of the population in the eastern Andes of central and southern Bolivia. We estimated a minimum population of 253 condors, an adult male‐to‐female ratio of 1:0.6, an immature male‐to‐female ratio of 1:0.9, and an adult‐to‐immature ratio of 1:1.1. At our five survey areas, estimated abundance ranged from 15 to 100 condors per area. Males outnumbered females in three areas and the opposite was true in two areas. Our estimated adult‐to‐immature ratio, overall and in each area, suggests that the populations could be reproducing at a high rate. As previously observed in other Andean Condor populations, skewed sex ratios could be associated with differences between sexes and age classes in habitat selection. Although our results suggest that Bolivian populations of Andean Condors are still reasonably large, population monitoring is urgently needed, including use of feeding stations throughout the entire Bolivian range of the species and intensive searches for roosting and nesting sites.     

Sisyrinchium humahuacense of sect. Segetia a new species from Argentina

Abstract

A new species from the Andean region of northwestern Argentina is described and illustrated: Sisyrinchium humahuacense. This species can be distinguish from its closest related species by three main characters: the presence of a conspicuous horizontal rhizome, the colour of the flowers and the presence of rudimentary leaves not splitting in fibers. A phylogenetic analysis based on DNA sequences supported the inclusion of S. humahuacense within the genus and as part of the section Segetia. Also, a key to species to identify S. humahuacense is presented herein.     

Systematics of Andean gladiator frogs of the Hypsiboas pulchellus species group (Anura,Hylidae)

Köhler, J., Koscinski, D., Padial, J. M., Chaparro, J. C., Handford, P., Lougheed, S. C. & De la Riva, I. (2010). Systematics of Andean gladiator frogs of the Hypsiboas pulchellus species group (Anura, Hylidae). —Zoologica Scripta, 39, 572–590. We revisit the taxonomic status of Andean species and populations of frogs of the Hypsiboas pulchellus group using multiple lines of evidence potentially indicative of evolutionary lineage divergence in anurans: differences in qualitative morphological or bioacoustic character states, no overlap in quantitative characters of advertisement calls, and monophyly of gene genealogies. We found qualitative and quantitative morphological characters to be extremely variable among species and populations of the group and thus of very limited use in assessing lineage divergence. In contrast, phylogenetic analyses based on 16S rRNA and cytochrome b sequences resolved highly supported clades that are in concordance with bioacoustic differences. The results support the specific distinctness of most nominal species recognized in the group, including the Bolivian Hypsiboas balzani and Hypsiboas callipleura, two species that were considered to be synonymous, and revealed the presence of an undescribed species from southern Peru, which is here described as Hypsiboas gladiator sp. n. In contrast, Hypsiboas andinus and Hypsiboas riojanus were mutually paraphyletic, and showed no differences in morphology and acoustic characters. Consequently, we regard the former as a junior synonym of the latter. However, we discovered that populations of H. riojanus from central Bolivia exhibit some degree of genetic differentiation and advertisement call differences with respect to Argentine populations, but sampling of these Bolivian populations is too sparse to draw taxonomic conclusions. Our phylogenetic results support the hypothesis that ancestral lineages of the Andean H. pulchellus group experienced successive splitting events along a latitudinal gradient from north to south.     

Fomitiporia baccharidis comb. nov., a little known species from high elevation Andean forests and its affinities within the neotropical Fomitiporia lineages

In the frame of a revision of the Fomitiporia species with pileate basidiomata in the New World, several collections originating from Andean, high elevation forests of Argentina were found to represent a terminal clade in multilocus phylogenetic inferences (including nuclear ribosomal partial LSU and ITS-5.8S, partial tef1-α and RPB2 genes). These collections also represent a singular morphotype within Fomitiporia, characterized by mostly pileate basidiomata, with a soft corky consistency, roughly sulcate pilei, a “duplex” context with a thin black line, and dextrinoid basidiospores, averaging 5.9?×?5.3 μm. It also has a well-marked autecology, occurring on shrubby trees in high elevation forests along the Andean range. A search in the literature for a name pointed toward Phellinus baccharidis, despite the fact that this species was repeatedly described with non-dextrinoid basidiospores. Examination of the type of P. baccharidis confirmed the main morphological features as previously described, but for the reaction of basidiospores in Melzer’s reagent, which was found to be strongly positive (dextrinoid), and an overall similarity with our own specimens; hence, the new combination Fomitiporia baccharidis is proposed. The species is redescribed and illustrated. It is so far known from Argentina and Ecuador. Its phylogenetic relationships with the South American Fomitiporia are briefly discussed.     

Phylogeny and diversification of the cloud forest Morpho sulkowskyi group (Lepidoptera,Nymphalidae) in the evolving Andes

The monophyletic Morpho sulkowskyi butterfly group, endemic of Andean cloud forests, was studied to test the respective contributions of Mio‐Pliocene intense uplift period and Pleistocene glacial cycles on Andean biodiversity. We sampled nine taxa covering the whole geographical range of the group. Two mitochondrial and two nuclear genes were analysed using a Bayesian method. We established a dated phylogeny of the group using a relaxed clock method and a wide‐outgroup approach. To discriminate between two hypotheses, we used a biogeographical probabilistic method. Results suggest that the ancestor of the M. sulkowskyi group originated during the Middle–Late Miocene uplift of the Eastern Cordillera in northern Peru. Biogeographical inference suggests that the M. sulkowskyi and Morpho lympharis clades diverged in the northern Peruvian Andes. The subsequent divergences, from the Late Miocene to the Late Pliocene, should have resulted from a dispersal towards the Northern Andes (M. sulkowskyi clade), after the closure of the West Andean Portal separating the Central and Northern Andes, and a southwards dispersal along the Peruvian and Bolivian Eastern Cordilleras (M. lympharis clade). Only a few divergences occurred at the very end of the Pliocene or during the Pleistocene, a period when the more recent uplifts interfered with Pleistocene glacial cycles.     

Genetic insights into the historical distribution of <Emphasis Type="Italic">Polylepis pauta</Emphasis> (Rosaceae) in the northeastern Cordillera Oriental of Ecuador

Scattered patches of Polylepis forest that occur within the 3,000–4,500 m altitudinal belt of the Andean Cordillera from Venezuela to Argentina have been hypothesized to be remnants of once continuous forests whose range became fragmented through anthropogenic activities that probably preceded the Spanish conquest. Allozyme variation of Polylepis pauta from 12 forest populations in three adjacent watersheds in Northeastern Ecuador was investigated to assess whether observed patterns of gene diversity were consistent with a more continuous historical range of the species and to evaluate the populations’ potential for restoration. Genetic diversity and polymorphism in P. pauta populations were higher than mean values for most wind pollinated and dispersed temperate and tropical tree species with regional distributions. Genetic differentiation among watersheds was lower than among populations within each watershed. Isolation by distance was not evident and several populations from different watersheds were more genetically similar than populations from the same watershed. Larger forest patches with broader altitudinal ranges had more alleles. Forest patches on steeper slopes and at higher elevations supported populations with less genetic diversity; this might have resulted from the predominance of vegetative reproduction in these landslide prone areas. The amount of genetic diversity maintained by P. pauta, coupled with low genetic differentiation among populations within and among watersheds, is consistent with a more continuous historical range of the species in Northeastern Ecuador and point to the Oyacachi basin as having the highest levels of genetic diversity.     

Long‐term monitoring of tropical alpine habitat change,Andean anurans,and chytrid fungus in the Cordillera Vilcanota,Peru: Results from a decade of study

The Cordillera Vilcanota in southern Peru is the second largest glacierized range in the tropics and home to one of the largest high‐alpine lakes, Sibinacocha (4,860 m). Here, Telmatobius marmoratus (marbled water frog), Rhinella spinulosa (Andean toad), and Pleurodema marmoratum (marbled four‐eyed frog) have expanded their range vertically within the past century to inhabit newly formed ponds created by ongoing deglaciation. These anuran populations, geographically among the highest (5,200–5,400 m) recorded globally, are being impacted by the chytrid fungus Batrachochytrium dendrobatidis (Bd), and the disease it causes, chytridiomycosis. In this study, we report results from over a decade of monitoring these three anuran species, their habitat, and Bd infection status. Our observations reveal dynamic changes in habitat including ongoing rapid deglaciation (18.4 m/year widening of a corridor between retreating glaciers from 2005 to 2015), new pond formation, changes in vegetation in amphibian habitat, and widespread occurrence of Bd in amphibians in seven sites. Three of these sites have tested positive for Bd over a 9‐ to 12‐year period. In addition, we observed a widespread reduction in T. marmoratus encounters in the Vilcanota in 2008, 2009, and 2012, while encounters increased in 2013 and 2015. Despite the rapid and dynamic changes in habitat under a warming climate, continued presence of Bd in the environment for over a decade, and a reduction in one of three anuran species, we document that these anurans continue to breed and survive in this high Andean environment. High variability in anuran encounters across sites and plasticity in these populations across habitats, sites, and years are all factors that could favor repopulation postdecline. Preserving the connectivity of wetlands in the Cordillera Vilcanota is therefore essential in ensuring that anurans continue to breed and adapt as climate change continues to reshape the environment.     

Revision of fleas of the genus Plocopsylla belonging to the ‘angusticeps–lewisi’ complex in the Andean biogeographic region,with the description of a new species

In Argentina, the Andean biogeographic region accommodates the most diverse population of fleas in the country. The Craneopsyllinae (Siphonaptera: Stephanocircidae) represent one of the most commonly found subfamilies in this region and show some endemism and high diversity. Plocopsylla is the most diverse genus of Craneopsyllinae; it includes 10 species mainly distributed in the Patagonian subregion, which parasitize sigmodontine rodents (Rodentia: Cricetidae). We describe and illustrate the morphology of the aedeagus in species of Plocopsylla that belong to the ‘angusticeps–lewisi’ complex. This character is of diagnostic value in differentiating among species. A new species of this complex, Plocopsylla (Plocopsylla) linardii sp. n., is described and identified by the shape and chaetotaxy of the distal arm of sternite IX, as well as by the shape of the median dorsal lobe of the aedeagus. New host associations for this complex and range extensions for most of its species are reported. Plocopsylla (P.) silewi is recorded for the first time in Argentina. The southern limits of the distributions of Plocopsylla (P.) lewisi and Plocopsylla (P.) wilesi are extended to Santa Cruz Province. The angusticeps–lewisi complex is found for the first time in San Juan Province. The information may be useful in epidemiological studies of flea‐borne diseases.     

Revision of the dioecious genus chersodoma phil. (Senecioneae,Asteraceae), including a new species and status change

A revision of the dioecious genus Chersodoma (Senecioneae, Asteraceae) recognizes nine species, including a new species, C. deltoidea Sagást. & M. O. Dillon, from northern Peru and a status change for a northwestern Argentine endemic, C. glabriuscula (Cabrera) M. O. Dillon & Sagást. Chersodoma is confined to the Andean Cordillera and is the only dioecious member of the Senecioneae in continental South America. A cladistic analysis of a morphological data set supports the monophyly of the genus and the recognition of two previously established subgenera. Subgenus Chersodoma contains three species (C. argentina, C. candida, C. jodopappa) with greatest diversity in the semi-arid puna of northwestern Argentina and adjacent Bolivia and Chile. Subgenus Diclinanthus B. Nord., contains six species (C. antennaria, C. arequipensis, C. deltoidea, C. juanisernii, C. glabriuscula, and C. ovopedata) with greatest diversity in Peru. A key to Andean genera of Senecioneae is provided. A discussion of species relationships and historical biogeography is presented as suggested by morphological parsimony analysis.