La Rioja Province Research Articles

Agistemus aimogastaensis sp. n. (Acari, Actinedida, Stigmaeidae), a recently discovered predator of eriophyid mites Aceria oleae and Oxycenus maxwelli, in olive orchards in Argentina

A new species, Agistemus aimogastaensis, is described with the aid of optical and Scanning Electron Microscopy. This mite is an important predator of two eriophyid mites (Aceria oleae and Oxycenus maxwelli) in olive orchards (Olea europaea, variety Arauco) in La Rioja Province. The problems related to eriophyids in olive orchards in Argentina are highlighted and photos of the damage on leaves and fruit are included.

Mate Marote: A flexible automated framework for large-scale educational interventions

There is big consensus that computer games may be an effective way of learning and many initiatives are being developed where aspects from cognitive sciences are being applied in the development of these games. In this article, we present Mate Marote, a flexible framework for large-scale educational interventions. Based on the delivery programs of computers to each student in Argentinian schools, we developed an environment that provides activities/games and registers usage statistics. This framework keeps installation up-to-date connecting with a central server as Internet connection is detected, synchronizing new activities, version updates and usage history. As a first testbed intervention, we deployed three games in La Rioja province (Argentina), where OLPC is the official program. These games were focused on training inhibitory control, working memory and planning skills. We found that usage statistics of games replicate previous results found at the laboratory, showing that this platform works as an intervention framework despite its unsupervised nature.

Milk molars or extra premolars in Mesotheriinae (Mesotheriidae, Notoungulata): New insights into an old controversy

A recently recovered specimen of Mesotheriinae (Mesotheriidae, Notoungulata) from the late Miocene-early Pliocene of La Rioja Province (Argentina), CRILAR Pv 433, corresponds to an individual with three upper premolars, which appears to be an “anomaly” among mesotheriines. The detailed study of this specimen, however, brings up an old controversy on the interpretation of different mesotheriine specimens with three upper or two lower premolars. After being described as different taxa, these were later considered to be juvenile representatives of other known species. The three upper or two lower teeth were interpreted as the milk molars DP2–4 and dp3–4, respectively, which would be replaced in adult life by two upper (P3–4) and one lower (p4) permanent premolars. The new material leads us to set up a different interpretation. In our opinion, all these specimens actually preserve the permanent dentition, corresponding to different ontogenetic stages of more or less young individuals. This consideration implies the necessity of a deep systematic revision of the whole subfamily, keeping in mind this new point of view and the ontogenetic variation within a species. Therefore, the presence of P2/p3 is not enough to define a different taxon at this moment. Pending this taxonomic revision, the dental morphology of CRILAR Pv 433 resembles both Typotheriopsis (e.g., upper premolars with one labial sulcus) and Pseudotypotherium (e.g., P4 with lingual groove, wide median lobe of M3) as these two late Miocene genera are currently characterized. Furthermore, P2/p3 could be expelled soon in the lifetime of individuals, and even the presence of P2/p3 could be a variable character within the same taxon; if so, this might reflect an evolutionary trend to the loss of a dental element within mesotheriines, but the revision of a large sample is necessary to support or reject these hypotheses.

Geastrum species of the La Rioja province, Argentina

A survey of Geastrum species from arid lands in the La Rioja province (northwestern Argentina) recovered fourteen species previously unreported from the province: G. arenarium, G. campestre var. famatinum, G. corollinum, G. fimbriatum, G. floriforme, G. glaucescens, G. hieronymi, G. aff. lloydianum, G. pampeanum, G. pampeanum var. pallidum, G. parvistriatum, G. rufescens, G. saccatum, and G. schmidelii. Of these, new records are G. corollinum for Argentina, G. arenarium for South America, and G. parvistriatum for the Americas, and G. campestre var. famatinum is proposed as a new variety. Each taxon is described, and photographs of basidiomes and SEM micrographs illustrating spores are provided for selected taxa.

Effect of European Union BSE-Related Enactments on Fledgling Eurasian GriffonsGyps fulvus

The effects of supplemental feeding on Eurasian Griffon range from increased survival and reproduction to population recoveries. In 2000, the appearance of Bovine Spongiform Encephalopathy (BSE) in Europe resulted in the implementation of the 1774/2002 regulation that required carcass removal and incineration at processing plants within the European Union and resulted in an immediate reduction of food availability for scavengers. We wished to evaluate the effect of the implementation of the reduced food availability on the scavenging Eurasian Griffon population. The study was conducted in La Rioja province (northern Spain). Eurasian Griffon fledglings are regularly brought to a rehabilitation center and can help evaluate the changes in nutritional condition before and after the enactment of the BSE regulations. A total of 47 first year griffons were sampled. Ptilochronology was applied to the rectrices, growth bars that are grown during the fledgling period were counted among nestlings before and after implementation of the EU-BSE directives. We found that the width of the growth bars, that represent the nutritional condition of the bird, showed significant differences over time. The growth bars before the implementation of the BSE EU-directives were significantly narrower than the subsequent period wherein carcasses were greatly reduced. The frequency of fault bars showed trends opposite to those of growth bars and there were significantly more fault bars in the pre-removal implementation period than the post-removal period. In conclusion, we consider this to be a result wherein the local adults with fidelity to their breeding colonies remained in the area while the non-breeding sub-adults and floaters have strayed in search of food. This has resulted in reduced inter-and intra-specific competition and only adults in good body condition breed resulting in healthier fledglings.

Selection against Aerial Dispersal in Ants: Two Non-Flying Queen Phenotypes in Pogonomyrmex laticeps

The South American seed-harvester ant Pogonomyrmex laticeps has dimorphic queens: ergatoid (permanently wingless) and brachypterous (short, non-functional wings). Surveys in western Argentina indicated that colonies near Chilecito, La Rioja Province, produced only ergatoid queens, while those near Punta Balasto, Catamarca Province (263 km away), produced only brachypterous queens. Brachypterous queens were significantly larger than ergatoid queens for 10 of 11 external characters, but both phenotypes had comparable reproductive potential, i.e., a spermatheca and a similar number of ovarioles. Using normal winged queens of the closely related P. uruguayensis for comparison, we determined that both queen phenotypes in P. laticeps had a full set of dorsal thoracic sclerites, albeit each sclerite was much reduced, whereas workers had a thorax without distinct dorsal sclerites. Sclerites were fused and immobile in ergatoid queens, while they were separable and fully articulated in brachypterous queens. Both phenotypes lacked the big indirect flight muscles, but brachypterous queens retained the tiny direct flight muscles. Overall, this dimorphism across populations indicates that there are alternative solutions to selective pressures against flying queens. We lack field data about colony founding strategy (independent or dependent) for either queen phenotype, but colonies at both sites produced numerous gynes, and we infer that all foundresses initiate colonies independently and are obligate foragers.

Mammals from the Salicas Formation (Late Miocene), la Rioja Province, Northwestern Argentina: Paleobiogeography, Age, and Paleoenvironment

This study analyzes a collection of fossil mammals from the Salicas Formation in the El Degolladito area, La Rioja Province, Argentina. The materials reported herein were recovered from two sites (site 1 and site 2). Reported mammals are Macrochorobates Scillato-Yané, Chasicotatus Scillato-Yané, and Hoplophorini indet. (Xenarthra, Cingulata); Paedotherium minor Cabrera, cf. Pseudotypotherium Ameghino (Notoungulata, Typotheria); Neobrachytherium Soria (Litopterna, Lopholipterna); Orthomyctera Ameghino, cf. Cardiomys Ameghino, Lagostomus (Lagostomopsis) Kraglievich, and Octodontidae indet. (Rodentia, Caviomorpha). This new mammalian assemblage, together with one previously recorded, has several taxa in common with mammalian associations from Central Argentina (i.e., La Pampa Province). Among those coming from Northwestern Argentina, the major affinity is with the El Jarillal Member (Chiquimil Formation) and then the Andalhuala Formation (both in Catamarca Province). The Salicas Formation fauna is considered as latest Miocene in age until new fossil discoveries and radioisotopic dates allow a better calibration. The fossil biota and geological data suggest that the Salicas Formation was deposited in flatlands, under warm and dry conditions. This environment was probably dominated by open grasslands, with forested areas near rivers and lagoons.

Range extension of Cavia tschudii Fitzinger, 1867 (Mammalia: Caviidae) and first record in Catamarca, northwestern Argentina

We report the first record of the genus Cavia and the species Cavia tschudii (Rodentia, Caviidae) in Catamarca province, northwestern Argentina, which represents a range extension of about 110 km southward for the species. The cranial and dental remains were recovered from an owl pellet sample found in eastern slopes of the Ambato range, at 1600 m elevation, in a highland grasslands-Chaco Serrano ecotone. According to the environmental continuity along the Ambato range, we suggest that the presence of C. tschudii in southernmost Catamarca and northern La Rioja province is likely.

Presencia de Gymnetron vittipenne Marseul, 1876 en la Península Ibérica (Insecta, Coleoptera, Curculionidae). Notas sobre su biología y distribución

The presence of the weevil Gymnetron vittipenne Marseul, 1876 in the Iberian Peninsula is confirmed definitively due to the collection of this species in northern Spain (La Rioja province). Previously this species was quoted as collected near Madrid, but this datum was always considered doubtful. Its presence in the Iberian Peninsula is of great biogeographical interest since its known range is located in eastern Europe and Central Asia. Biological data on this species are given for the first time.

Morphological diversity and phylogenetic relationships within a South-American clade of iguanian lizards (Liolaemidae: Phymaturus)

With 36 species and at least nine potentially independent lineages (not formally described yet) occurring mostly in theAndes and adjacent Patagonia and Puna plateau areas, Phymaturus lizards represent one of the most endemic vertebrategroups of the arid southwestern region of South America. Phylogenetic relationships among species of Phymaturus areinferred using mainly a morphological data set of 206 characters. Also available sequences of mitochondrial DNA for sev-en terminals were added for a total evidence analysis. Most information is included in the discrete characters block; mostcharacters involve color pattern, osteology and squamation. Continuous characters were taken from body proportions,squamation and skeletons. Among morphological data, binary polymorphic characters were analyzed applying the scaledcoding criteria. Continuous characters were entered in the analysis using standardized ranges, a method that allows a sim-ple optimization to estimate distances/costs avoiding the arbitrary coding as discrete characters. For our parsimony anal-yses we chose the implied weights method, which underweights homoplastic characters. Several runs were madeanalyzing all the information combined and also separating morphological from molecular datasets. Binary polymor-phisms were also analyzed as missing data. All characters affected by sexual dimorphism were analyzed separating thesexes; female information was more congruent with the total evidence analysis. Characters involving continuous and poly-morphic information are relevant for searching and building phylogenetic hypotheses in Phymaturus. There exists signif-icant congruence between the molecular information analyzed in this study and previous published analyses. Within bothmain clades of Phymaturus, northern subgroups are those more recently originated during the genus diversification. Spe-cies belonging to the puna subclade of the palluma group are arranged in two natural groups, one distributed in the north(Catamarca and La Rioja provinces), and the other in the south, La Rioja and San Juan provinces. Within the patagonicusgroup, the majority of the species are arranged in a south-central Chubut clade, eastern-central Chubut clade, central Rio Negro clade and a Payunia clade.

The trilobiteReedops(Phacopidae) in the Lower Devonian of Argentina (Malvinokaffric Realm)

The trilobiteReedopsis documented from strata probably corresponding to the middle part of the Talacasto Formation in the Sierra de las Minitas, at the northernmost extent of the Precordillera in La Rioja Province, northwestern Argentina. The specimens resemble the type species of the genus,R. bronni, indicating a Pragian (Early Devonian) age for the strata, and suggesting the occurrence at this time of faunal exchange between the Old World Realm, particularly the Bohemian area, and the Malvinokaffric Realm. The taxon represents the first Early Devonian macrofaunal element in the Malvinokaffric Realm with global biostratigraphical significance.

Argentinean Species of Chalarus Walker (Diptera: Pipunculidae): New Records and Description of Chalarus tani n. sp.

The Argentinean species of Chalarus Walker were studied. Pipunculidae adults belonging to four species, C halarus chilensis Collin, Chalarus triramosus Rafael, Chalarus absonus Rafael and Chalarus tani n. sp. were described based on two male specimens collected in the La Rioja and Tucuman Provinces, northwestern region of Argentina. Chalarus absonus is recorded for the first time in Argentina. New distributional data and an identification key to the adult males of the Argentinean representatives are provided including figures.

Two new species of the genus Plumaroides Brothers, 1974 (Hymenoptera: Chrysidoidea, Plumariidae) from Argentina

Two new species of the genus Plumaroides Brothers, 1974 from Catamarca and La Rioja provinces of Argentina P. aquilusDiez & Fidalgo, sp. nov. and P. tapilophus Diez & Fidalgo, sp. nov. are described and illustrated. A key to separate males of five known species of Plumaroides is provided.

El Alisal : a new locality with trace fossils of the Puncoviscana Formation (late Precambrian-early Cambrian) in Salta Province. Argentina

The Puncoviscana, Suncho and Las Aguaditas/Negro Peinado formations represent a thick siliciclastic folded succession that crops out on a strip about 800 km long and 150 km wide in northwestern Argentina (Jujuy, Salta, Tucuman, Catamarca and La Rioja provinces). These sequences are lithologically characterized by very lowgrade metamorphic sediments grading from slates to schists; turbidites, pelagic clays, limestones and volcanic rocks. On the basis of paleoichnological data, these units have been assigned to the late Precambrian-early Cambrian. A new locality bearing well preserved trace fossils from the Puncoviscana Formation is described herein. The outcrop is located about 45 km west of Salta city (Salta Province), displaying an alternation of colored differentiated grayish-bluish slates and fine sandstones. Ichnofossils include Cochlichnus anguineus HITCHCOCK, Helminthoidichnites tenuis FITCH, Helminthoida isp., Monomorphichnus lineatus CRIMES, LEGG and MARCOS ARBOLEYA, Planolites isp. and Torrowangea? isp., as well as some limb marks and a few slightly bended smooth trails (indet.). An Early Cambrian age for the succession at El Alisal as well as some environmental considerations are allowed by the ichnological association. In addition, the ichnogenus Planolites is mentioned for the first time from the “red shales and conglomerate type” facies at the neighbor locality of Chorrillos.

WATER VAPOR CONDUCTANCE OF THE LOWER CRETACEOUS DINOSAURIAN EGGS FROM SANAGASTA, LA RIOJA, ARGENTINA: PALEOBIOLOGICAL AND PALEOECOLOGICAL IMPLICATIONS FOR SOUTH AMERICAN FAVEOLOOLITHID AND MEGALOOLITHID EGGS

The water vapor conductance (GH2O) of the neosauropod eggs from the Lower Cretaceous Sanagasta nesting site in La Rioja Province, Argentina, was examined and compared with other Cretaceous Argentinean oological material. The 2900 mgH2O/day·Torr GH2O of the Sanagasta eggshells confirms an extremely moist nesting environment and supports field observations of dug-out nests in a geothermal setting. The observed thinning of the outer eggshell surface during incubation increases gas conductance and concomitantly decreases eggshell mechanical resistance during the late ontogenetic stages, thus facilitating embryonic development and hatching. The Sanagasta and Entre Rios Province faveoloolithid eggs display the highest and comparable GH2O values and share several morphological and diagenetic characters, indicating comparable nesting strategy in geothermal settings. However, the faveoloolithid Yaminue and La Pampa Province specimens cluster together with lower GH2O values closer to the megaloolithid eggs. The GH2O of the megaloolithid egg Megaloolithus patagonicus was reconsidered and new results are now congruent with other reported megaloolithid GH2O values. Additionally, we hypothesize that Y-shaped pore canals of M. patagonicus, which upper sections reach only the top third or half eggshell thickness and, a wider section in the middle would not compromise the overall egg mechanical resistance like vertical pores connecting directly the outer to the inner eggshell surfaces. Such pore spatial arrangement and geometry would enhance, as the eggshell thins during incubation, a greater GH2O, GO2 and GCO2 and facilitate embryonic development in high moisture nesting contents. Overall, data suggests that neosauropod nesting and brooding behaviors were dependent on elevated moisture nesting environments.

The geology and palaeoecology of the newly discovered Cretaceous neosauropod hydrothermal nesting site in Sanagasta (Los Llanos Formation), La Rioja, northwest Argentina

The recent discovery of the Cretaceous Sanagasta geothermal nesting site in the Los Llanos Formation, La Rioja Province, northwestern Argentina, has shed light on new and unexpected neosauropod reproductive behaviours. Here we recapitulate the palaeontological discovery at Sanagasta and the oological characterization of the nesting site (reported in 2010). In addition, we describe in detail the geology, sedimentology, petrology, and geochemistry of the nesting site with the goals of assessing the palaeoenvironment of the Los Llanos Formation at this site. The Sanagasta Geologic Park, where the nesting site is located, represents a local expression of a geothermal process that occured in the Sierras Pampeanas during the Cretaceous Period. This geothermal cycle allows for the first time an Early Cretaceous dating (Hauterivian–Aptian) for the Los Llanos Formation, which is further supported by the occurrence of notosuchians, and ornithopod, sauropod and theropod dinosaurs in other exposures of the same formation in La Rioja Province. As such, in addition to shedding light on neosauropod palaeobiology and their nesting environment, this investigation clarifies longstanding geological issues pertaining to the sedimentary basins in the Sierras Pampeanas Orientales (central-west Argentina).

DIFERENCIAS SEXUALES Y ETARIAS EN LA ACTIVIDAD DIARIA Y ESTACIONAL DE UNA POBLACIÓN DE LIOLAEMUS KOSLOWSKYI (LIOLAEMINI)

A B S T R A C T. — The pattern of activity of Liolaemus koslowskyi populations from NE of the La Rioja Province, were studied between October 1998 and April 1999 by performing transects between 08:00 and 19:00 hs. The species present unimodal pattern of activity during both autumn, and spring; and bimodal pattern during summer. In terms of the number of active individuals, there was a significant difference between adults and juveniles in February and April and not there was significant difference between males and females. The males were active at higher temperature ranges than females and juveniles; which could suggest that would be related to territorial defense by males.

The Upper Ordovician trinucleid trilobiteBancroftolithusfrom the Precordillera of Argentina

The trinucleid trilobiteBancroftolithusBaldis and Pöthe, 1995 includes a group of species from Sandbian strata of the Argentine Precordillera. The monotypicHunickenolithusBaldis and Pöthe, 1995 from the Las Aguaditas Formation at its type locality in San Juan Province is placed in the synonymy ofBancroftolithus.Of four nominal taxa from the Las Aguaditas Formation,B. pozensisBaldis and Pöthe, 1995, andB. hughesiBaldis and Pöthe, 1995 are retained, and both are revised based on new collections from the type locality that include ontogenetic series from the protaspid period. Two protaspid stages are recognized in both species. Three additional species (Bancroftolithus alkin. sp.,B.cf.B. pozoensis, Bancroftolithussp.) from broadly coeval strata in the Las Plantas Member of the Las Vacas Formation in La Rioja Province are identified as the closest relatives of the Las Aguaditas species.Bancroftolithus alkialso occurs in the Los Azules Formation in San Juan Province. The five species included in this regional clade exhibit significant morphological differences in the lower lamellae, an unusual feature among the Trinucleidae.Bancroftolithusis evidently most closely related to the Australian Katian genusParkesolithus.The two are not convincingly assigned to any of the existing trinucleid subfamilies.

The Nest Architecture of Diadasia hirta (Jörgensen) (Apidae: Emphorini) from La Rioja Province, Northwestern Argentina

Nests of Diadasia hirta are documented here for the first time. Nests have a cylindrical turret, one vertical principal burrow, cells disposed in linear series, and an oval pollen mass. Almost all observed behavioral traits and nest architecture features resemble those of other species of Diadasia. One exceptional behavior observed was pollen removal from the nest.

Mammalia, Rodentia, Sigmodontinae Wagner, 1843: new Locality records, filling gaps and geographic distribution maps from La Rioja province, northwestern Argentina

Sigmodontine rodents are well represented in northwestern Argentina, but information regarding their distribution in La Rioja is scarce. We add new information for seven species from seven localities in the Famatina range. These new records were obtained using both captures and owl pellet analysis. We cite the first record of Neotomys ebriosus in La Rioja. The collection locality is unusual for this species because of its low altitude and xeric conditions. Other notable results include the second record of Abrothrix andinus and of the genus Oligoryzomys at the province.