Revista del Museo Argentino de Ciencias Naturales, Nueva Serie

Print ISSN: 1514-5158
The magnificence and diversity of the extant flora, with plants adapted to almost all environments and latitudes throughout the world have originated, and originate, innumerable questions to all who study its fossil record. This Museum and its researchers have played a leading role in answering many of these questions almost from the very beginning. In early stages of the Museum the fossil plant record was highlighted by Hermann Burmeister and Florentino Ameghino, among others. After 1951, with the formation of the Paleobotany Division, the discipline began to have a significant rise in the Museum with growing and progressive incorporation of researchers, increase of scientific collections and the transfer of knowledge through scientific meetings and publications in renowned national and international journals. In this context, it is worth noting the task conducted by Dr. Alberto Castellanos and the first Heads of the Paleobotany Division: Drs. Carlos Menéndez (1951-1975), Wolfgang Volkheimer (1975-1987) and Sergio Archangelsky (1987-2006) who laid the foundations that would position the Museum as one of the most important centers in Argentina on the study of Paleobotany.
In this paper a tarsometatarsus, a mandibular fragment and a synsacrum are described and assigned to T. alba. Such material comes from three localities situated in the southeast and northeast of the Buenos Aires province. Here, we found exposed sedimentary sequences including the geochronologic interval Early Pleistocene-Holocene (Ensenadan, Bonaerian, Lujanian and Platan). They represent the first fossil records for this species in Argentina and the oldest one for South America. We found also direct evidence of trophic associations between a predator like T. alba and microvertebrates pellets in the Pleistocene of Argentina.
Ten new species of the genus Phytocoris Fallén, 1814 are described from Argentina and Chile: P. aniatuyensis n. sp., P. barrigai n. sp., P. conesensis n. sp., P. curicoensis n. sp., P. dimorphicus n. sp., P. elguetai n. sp., P. guaikuru n. sp., P. guarani n. sp., P. jujuyensis n. sp. and P. vilela n. sp. Their habitus and, when possible, the genital structures of both sexes, are figured.
Understanding how biodiversity influences and modifies ecosystem processes depends on our knowledge of the roles of the individual species. In the intertidal rocky shore communities, the molluscs are the main grazers and among them are found the pulmonate limpet Siphonaria lessoni. Here it was used a manipulative field experiment to test community responses to the deletion of the grazing from the mid-intertidal zone on warm-temperate rocky shores of Buenos Aires Provinces (Southwestern Atlantic). S. lessoni was removed from four plots (20 x 20 cm) by a five months period (summer-autumn), in order to analyze the grazing effect on the intertidal assemblages dominated by the mytilid Brachidontes rodriguezii. It was compared the specific richness, biomass and production between "limpet removing plots" and "controls plots". After the mentioned time, in the "limpet removing plots" the biomass average of the algae assemblages was fifty times higher than in "controls plots". Specific richness of species assemblages of mussels did not show significant variation between treatments. Community structure associated to B. rodriguezii did not show significant variation between treatments. In accordance with the season of year when this experiment was performed, the results suggest that the biomass of epibenthic algae of B. rodriguezzi community was regulated by the grazing activity of the limpet S. lessoni.
Mapa de ubicación del área de estudio, con localización geográfica de los registros de Tremarctos ornatus, en las provincias de Salta y Jujuy, noroeste de Argentina, según datos obtenidos entre 2001 a 2006. Cada globo, representa un registro.
Esquema de comparación de huellas (Hand/ Mano & Foot/Pié) de diferentes mamíferos nativos del área de estudio, con T. ornatus en un sustrato ideal areno-arcilloso. Dibujo de Fernando Del Moral.
The presence of Andean bears (Tremarctos ornatus) in Argentina has been disputed due to the absence of confirming evidence. Many Andean bear experts currently doubt on their presence in this country. Nevertheless, the Tucuman-Bolivian Forest or Yungas is a typical ecosystem where this species can be found, particularly in the studied area, in which the habitat appears to be of high quality for bears. Between 2001 and 2006, 23 cases of evidence on the presence of Andean bears in the provinces of Salta and Jujuy were recorded. Footprints, food remains and scats were found. In addition, natives, farmers, and hunters where interviewed to collect new data of this species. The conclusion is that the Yungas Forest of northwestern Argentina must be considered an area with high probability of maintaining a resident population of Andean bears. Although this is probably a small and perhaps isolated population, the permanent presence of Andean bears in northwestern Argentina might not longer be doubted.
The knowledge of the Andean bear's (Tremarctos ornatus) distribution is fundamental for evaluating the status of the species and the development of conservation measures such as the declaration of new conservation areas or the implementation of the management measures. This study aimed perform some field assessments between the years 2007 and 2008, in the Andean north eastern and southern limits of the species' range, using the method of tracking mountain ridges to obtain first hand data on the presence/absence of the Andean bear in these areas. We have obtained 101 current records of the species, including the central-western of Venezuela and the northwest tip of Argentina. Finally, we discuss the biogeographic implications of the reported data.
Resumen Somotrichus unifasciatus (Dejean, 1831) (Coleoptera: Carabidae: Lebiini) introduced in Buenos Aires Province, Argentina. The presence of this species is recorded for three localities in the northeast of Buenos Aires Province: Exaltación de la Cruz (Capilla del Señor), Pergamino (Peregamino city) and Ramallo (Ramallo city) . It is here redescribed for adequate identification. Previous records for this species in the New World include only Guadelupe and Brazil. Numerous specimens were collected in Capilla del Señor and Perga-mino from the underside of piles of avian manure mixed with residual balanced food fallen from chick breeding cages associated with several Arthropoda including larvae and adults of the cosmopolitan tenebrionid species Tribolium confusum Duv. and Alphitobius piceus (Oliv.).The former species may probably be among the preferential preys of this carabid beetle.
Carpometacarpo izquierdo. A, Belonopterus chilensis (MLP 04-V-2-1); B, B. chilensis; C, B. downsi; D, B. resplendens. Vistas: Izquierda, dorsal; centro, posterior y derecha, ventral. Escala 1 cm. B-C-D, reproducidos de Campbell (1979).
Belonopterus lilloi nov. sp. Extremo distal de húmero derecho (MACN Pv 12475, Holotipo) en vistas: a, anterior; b, posterior; c, distal. Escala 1 cm.
Resumen The presence of the genus Belonopterus Reichenbach, 1852 (Aves, Charadriidae) in the Pleistocene of Argentina, with the description of Belonopterus lilloi n. sp. Fossil material belonging to the genus Belonopterus is described in this work. These specimens consist on a complete carpometacarpus and a well preserved distal end of humerus, coming from the Pleistocene of Buenos Aires province, Argentina. The carpometacarpus is referable to the living species Belonopterus chilensis, which actually inhabits the same zone. The distal end of humerus is similar in size to this living species, but differs in several anatomical traits such as, the peculiar morphology of the ventral condyle. These differences allow us to identificate this specimen as a new species of Belonopterus. Both materials constitute the oldest fossil record for the genus and for the subfamily in America, and indicate that a varied Vanellinae fauna was present in the Pleistocene of South America.
In 1881 Ameghino described the fossil human remains of Arroyo Frias as its more relevant finding, considering it to be the oldest of Pampean sites since the remains were unearthed from his Pliocene Upper Pampean. He realized this finding by the end of 1872, announces it to Burmeister in January of 1874 and, in September he continued the excavation with professor Ramorino. In spite of that, he will not obtain any official recognition since, in 1876, the commissioners of the Sociedad Cientifica Argentina explored the area of the Canada de Rocha creek, believing they were in the Frias valley. Victims of this confusion Moreno, Zeballos and Lista declared that Ameghino mistakenly attributed an older "diluvian" age to very recent geologic layers, strongly eroding his reputation and scientific credibility. It is analyzed here the historical context of this disagreement that stigmatized for decades the archeological prospection of Pampean plains, while we present a geologic model with new 14C and OSL dates, in order to understand why Ameghino erroneously attributed a great antiquity to these layers. Also arise other geoarchaeological issues when these new data are confronted with the detailed descriptions of this author.
The skate Atlantoraja platana, commonly known in Argentina as "raya platana", is endemic to the Southwest Atlantic. It is distributed from Brasil (24°S) to north Patagonian waters (42°11'S). In this study the morphometric aspects of this skate were described. In the San Matías gulf (41°-42°S y 64°-65°W), a total of 778 females and 709 males were sampled from different sources between 2004 and 2006. The total length ranged was 19 to 89 cm for females and 19 to 79 cm for males. Atlantoraja platana was sexually dimorphic in total length-weight and total length-disc width relationships. Since 41 cm onwards the females are being heavier than males. The total length-weight relationship was Pt= 0.0132 × Lt 2.91 for females and Pt= 0.0222 × Lt 2.77 for males. The total length-disc width relationship was DW= 7.27 + 0.762Lt for females and DW= 7.768 + 0.798Lt for males. This is the first report of morphometric relationships of this species in the Argentinean Sea and they should be used for comparison purpose between different latitudinal localizations of this skate.
The museums of our continent are a result from a combination of factors, such as cultural trends, rivalry between cities, countries, and research teams, and the affinities or exchanges with metropolitan centers. Alliances and scientific wars determined the course of these institutions. As we show in this paper, in the 1880s and 1890s, competition between individuals, the Museo General de La Plata of the Province of Buenos Aires and the Museo Nacional of Buenos Aires would define the paths they would follow and a race for the possession of a large fossiliferous collection.
Map showing the known localities of Phoniocercus sp. 
Phoniocercus sp. from Argentina, living speci- men in a defensive posture (Photo by R. D. Sage). 
Scorpion genus Phoniocercus Pocock, 1893 (Bothriuridae) is endemic to the cold humid forests of the southwestern part of South America. Up to now the known distribution of the genus was restricted to the Valdivian forests of southern Chile. In this contribution we present the first record from Argentina and the first records from central Chile. New data about their ecology and systematics are also presented.
Resumen Holochilus chacarius Thomas, 1906 (Mammalia, Rodentia, Sigmodontinae) in Middle Delta of the Paraná River, Entre Ríos, Argentina. We describe the presence of Holochilus chacarius in the Victoria Island Zone included in the Middle Ddelta of the Paraná Rriver (Entre Rríos, Argentina). We collected and analysed pellets of the Striped Oowl (Pseudoscops clamator). All cranio dental items that were identified and measured belong to the Cchaco Marsh Rrat. We postulate that its occurrence is becoming less casual and is associated with the high climate variability and extreme events of flooding and drought that have affected the area in recent years. Tthese events would favour the ingression and eventual establishment of these rodents in the study area.
Glanidium ribeiroi was described from the Iguaz� River basin in Paran� State, Brazil. In Argentina, the species was reported for the Urugua-í stream and the Iguazú River basins in the Misiones province, and some tributaries of the middle Paraná River basin, such as Cuña Pirú in Misiones and the Salado River at Santa Fe province. After a critical review of all the Argentinian records of Glanidium ribeiroi we concluded that the specimens reported from Cuñá Pirú should be referred to Tatia neivai (Ihering, 1930) and the record of G. ribeiroi from Santa Fe province was based on a specimen that is here assigned to Microglanis carlae Vera Alcaraz, da Graça & Shibatta, 2008. In this way, the southernmost records for G. ribeiroi are to be excluded and the endemic nature of this species is confirmed for the Urugua-í and Iguazú basins.
Psolus patagonicus Ekman, 1925. Holotype: ZMH E4173, dorsal view. Scale bar: 1 cm. Psolus marcusi Tommasi, 1971: 4. Psolus antarcticus: Ludwig, 1897 (non Philippi, 1857).
Psolus patagonicus Ekman, 1925. Ossicles: A. plates from the sole, B. end plate. Scale bar: 50 μm. 
Psolus patagonicus Ekman, 1925. Ossicles: A. Plates from the ventral side, B. Curved plates from podia, C. Curved plates from tentacles. Scale bar: 100 μm. 
Psolus marcusi Tommasi, 1971. Drawings from Fig. 9 and 10 of Tommasi (1971). A. lateral, B. dorsal, C. ventral view, D-E. plates, F-G. curved plates with multiple perforations. 
Psolus patagonicus Ekman, 1925 is redescribed from material including the holotype, deposited in the Zoologisches Museum Hamburg (ZMH), and specimens of the Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" (MACN-In). Psolus marcusi Tommasi, 1971 is stated as a junior synonym. Since also the specimens used by Ludwig in 1897 to report the brooding behavior of Psolus antarcticus (ZMH: E4168) are identifiable as P. patagonicus, the latter is the only South American psolid holothuroid known to be a brooder.
For almost fifteen years, José Yepes organized and increased the collection of mammals of the Argentine Museum of Natural Sciences of Buenos Aires. This zoologist was mainly dedicated to the study of the argentine xenarthrans and rodents as well as to the promotion of zoogeography. He made observations and collections in several regions of western Argentina, predominantly in mountainous and hilly areas. He also participated in wildlife protection movements in the 1940s. This article relates some biographical information of this zoologist and some material and institutional aspects of his scientific practices. © 2018 Museo Argentino de Ciencias Naturales Bernardino Rivadavia.
Resumen The Late Cretaceous (Maastrichtian) Lameta Formation of central India has yielded dissociated elements of a variety of predatory dinosaurs, most of them coming from a quarry named the "Carnosaur bed." The materials were described by Huene and Matley nearly 70 years ago. They recognized nine theropod species, which they sorted out into the theropod subgroups "Carnosauria" and "Coelurosauria". Huene and Matley also described a considerable amount of theropod hindlimb bones (e.g., femora, tibiae, metatarsals, and pedal phalanges) that they could not refer to any of these species, but vaguely interpreted as corresponding to "allosaurid" or "coelurosaurid" theropods. We reviewed the available collection of Cretaceous theropods from Bara Simla housed at the Geological Survey of India, Calcutta, arriving to the following conclusions: 1) Indosuchus and Indosaurus are abelisaurids, as recognized by previous authors, but available information is not enough to judge whether they are synonyms; 2) Laevisuchus indicus is a small abelisauroid, related to Noasaurus and Masiakasaurus on the basis of their peculiar cervical vertebrae; 3) the controversial taxa " Compsosuchus", " Dryptosauroides", " Ornithomimoides", and " Jubbulpuria" are represented by isolated vertebrae corresponding to different portions of the neck and tail, and also exhibit abelisauroid features; 4) hindlimb bones originally referred to as "allosaurid" and "coelurosaurian" also exhibit abelisauroid characters, and bones of large size are tentatively referred to as corresponding to Indosuchus or Indosaurus, whereas some pedal bones of smaller size may belong to Laevisuchus; 5) two kinds of abelisaurid feet are apparent: one in which the phalanges of digit III and IV are robust, and another type in which the phalanges of digit IV are transversely narrow and dorsoventrally deep. This review demonstrates that all of the theropod elements discovered at the "Carnosaur bed" belong to a single theropod clade, the Abelisauroidea
The reproductive biology of M. schmitti collected from the commercial bottom trawl fishery operating in Puerto Quequén, Argentina is investigated in the present study. The specimens were sampled seasonally during 2003–2004. The number of sharks collected was 637 (298 males and 339 females), including 190 pregnant females with 1,103 embryos. Size ranges for males were 419 – 819 mm total length (LT) and 417 – 951 mm LT for females. Total length and body weight relationship was different between sexes (P<0.05). In contrast, embryos did not show differences between sexes (P>0.05). Size frequency shows that females attain larger length and weight than males. Fifty percent (50%) of maturity size shows that males mature at a lower LT (567 mm) than females (598 mm). The left testis reached larger weight and length than the right one (P<0.01). Average values of the IG and IH per season varied significantly for males and females (P<0.05). Average values of the white and yellow ova per season showed significant differences (P<0.05). The maximum diameter of the left oviducal gland was greater than the right one (P<0.05) and both exhibit seasonal changes (P<0.05). At greater LT the females had more embryos per brood (P<0.01) than bigger puppies (P>0.05).
Resumen Evolution of the coastal bottom trawl fishery at Puerto Quequén, Buenos Aires province, Argentina: 1999-2010 period. Tthe occurence of the “fishing down food web” process at Puerto Quequén was studied, based on the relationship between the temporal pattern of landings and indirect indicators as the mean trophic level an the “fishing in balance” index. Ttotal landings were obtained from vessels landing reports. For each year the mean trophic level of fishery and the “fishing in balance” index were calculated. For the analysis of the temporal series of the mean trophic level, a linear regression model was used. With relation to total landings, no changes were � distinguished. ten species represent more than the 90 %of total landings. the regression analy-Tten %% analysis showed a significant and positive tendency. Nno declination in the mean trophic level of fishery was observed, thus the “fishing down food web” process is no occurring at Puerto Quequén. However, the “fishing in balance index” shows that the fleet has reached a level of limit expansion, starting, probably, with a descendent process making the fishery unbalanced in ecological terms and turning it no sustainable.
The occurence of the "fishing down food web" process at Puerto Quequén was studied, based on the relationship between the temporal pattern of landings and indirect indicators as the mean trophic level an the "fishing in balance" index. Total landings were obtained from vessels landing reports. For each year the mean trophic level of fishery and the "fishing in balance" index were calculated. For the analysis of the temporal series of the mean trophic level, a linear regression model was used. With relation to total landings, no changes were distinguished. Ten species represent more than the 90 % of total landings. The regression analysis showed a significant and positive tendency. No declination in the mean trophic level of fishery was observed, thus the "fishing down food web" process is no occurring at Puerto Quequén. However, the "fishing in balance index" shows that the fleet has reached a level of limit expansion, starting, probably, with a descendent process making the fishery unbalanced in ecological terms and turning it no sustainable.
Extremo distal de fémur de Quilmesaurus curriei A-D y Carnotaurus sastrei E-G, en vistas anterior (A y E), posterior (B), medial (C y F) y Distal (D y G). Abreviaciones: eg: surco extensor; lc: cóndilo lateral; mc: cóndilo medial; mcdl: condílido medial; mdc: cresta medio-distal. 
Resumen Quilmesaurus curriei Coria, 2001 (Dinosauria, Theropoda). Its taxonomic validity and phylogenetic relationships. A comparative analysis of the Cretaceous theropod Quilmesaurus curriei from the Río Negro province, Patagonia, Argentina was performed in order to elucidate its phylogenetic relationships. Quilmesaurus was considered as basal Tetanurae by Coria (2001), however, Kellner & Campos (2002) suggested that this theropod could be a possible Abelisauria. In our analysis, we observed that the lack of fusion of the tibia with the astragalus- calcaneum is not an exclusive character for Ceratosauria; moreover, the mediodistal crest of femur is commonly well developed in Abelisauroidea. The great development of the distally expanded cnemial crest and the asymmetrical distal end of the tibia are characteristics of Abelisauridae. Finally, other characters like a distally directed process at the end of the cnemial crest and the asymmetry in the origin of the expansion of the malleolii in distal tibia are regarded as synapomorphies of Carnotaurinae. Therefore, Quilmesaurus curriei is considered to belong to Abelisauridae, and it is possibly a member of Carnotaurinae. On the basis of the available evidence, it is not possible to identify autapomorphic characters that allow validating Quilmesaurus curriei, and for this reason we consider it as a nomen vanum.
Curva de acumulación de conocimiento de Carabidae a través de la historia científica.
Carabidae are one richest families of Coleoptera. A total of 39 tribes are known from austral South America (76.4 % of the Neotropical fauna). Tribal richness is characteristic of transition zones, in this case, between the Neotropical and the Andean regions. The number of occuring species in Austral South America represents 23 % of the Neotropical species, with many endemic and relictual tribes, mainly of Pangeic or Gondwanic origin. Many years of work were needed to reach this knowledge on Austral South American Carabidae. The present contribution present a synopsis to scientific knowledge during all this time, including scientific studies of the carabid fauna of southern South America through 237 years of systematic work. The tendencies that seem to have influenced the description rates during this time are also indicated. Political, economic and historical events are analysed considering their influence on the amount of described taxa.
Resumen Butlerite (Fe OH SO4 2H2O) from Santa Elena mine, province of San Juan, Argentina. Idiomorphic crystals of Butlerite from Santa Elena mine, Calingasta, San Juan, Argentina, were used for this study. Butlerite (Fe OH SO 4 2H 2O) has the following characteristics: monoclinic, Prismatic class, space group P 2 1/ m; a = 6.499(1), b = 7.378(1), c = 5.848(1)Å, ß = 108º28'(5), a:b:c = 0.8809:1:0.7926, cell volume 265.98 Å ³, Z=2. The transparent crystals are colorless to pale yellow, the fine aggregates are yellow orange, the streak is pale yellow, the luster is vitreous. The crystals are tabular, measuring up to 1 mm across; the predominant forms are {001}, {100}, {110}, {011}, and {101}. The strongest peaks in the X-ray powder diagram are, in Å: 4.98 (100), 3.165 (52), 3.597 (17), 3.234 (14), 2.495 (14), 4.74 (9), 4.43 (9). Butlerite is biaxial (+), a = 1.595(1), ß = 1.666(1), g = 1.743(1) Na light, 2 V 85º, Z = b, X Ù c = -17º, pleochroism X = colorless, Y = faint yellow, Z = light yelow, high birefringence, cleavage {100} very good, fragile, hardness 2 1/2, density 2.552 g/cm ³ (meas.), 2.559 g/cm ³ (calc.). Parabutlerite, the orthorhombic dimorph, dipyramidal class (2/ m 2/ m 2/ m), spatial group Pmnb, is associated with butlerite.
The aim of this study is to provide a synthesis of the present knowledge of the marine Porifera in the Southwest Atlantic between 35º S and 56º S, and between the coast of Argentina and 50º W. The analysis of 34 taxonomic publications produced a list of 149 oceanographic stations and 28 coastal localities with records of Porifera for the study area. A total of 196 species, 5 subspecies and 1 variety of marine sponges was recorded, 187 of which belong to the Demospongiae, 10 to the Calcarea and 5 to the Hexactinellida. The most widely distributed sponges in the study area are Dasychalina validissima, Iophon proximum, Mycale magellanica, Tedania massa and Tedania spinata, all Demospongiae. The sampling effort was unequally distributed, reach-ing a maximum concentration off Buenos Aires Province and around the Malvinas/Falkland Islands. The biodiversity of marine Porifera of Argentina along 21 degrees of latitude is closely related to the concentration of the sampling effort. It appears to be highest in thoroughly surveyed areas, such as around Mar del Plata, Port Stanley and the coast of Tierra del Fuego. No correlation was found between species number and depth. The richest stations were recorded around 130-140 m. Biodiversity of Porifera is weakly but significantly correlated with latitude, since stations between 50º S and 55º S were on average richer than those located off Buenos Aires Province. Knowledge of the geographic distribution of marine Porifera in Argentina is fragmentary. Much more basic information is needed, particularly for the continental shelf off Río Negro and Chubut Provinces. Information on biodiversity of marine Porifera in the Southwest Atlantic off the coast of Argentina is scattered in more than 30 taxo-nomic studies published since 1882. Most species recorded for this area have been dealt with in the results of the Challenger (Ridley & Dendy, 1886, 1887; Sollas, 1886, 1888; Schulze, 1887), Scottish (Topsent, 1913), Discovery, William Scoresby (Burton, 1932) and Swedish (Burton, 1934) expeditions, as well as in the description of the Porifera stored in the Museo Argentino de Ciencias Naturales (Burton, 1940). In the last decades, several studies have also been published on the sponges of Tierra del Fuego (Sarà, 1978; Cuartas, 1995a), Buenos Aires Province and north Patagonian gulfs (Cuartas, 1985, 1986 a, b, 1987, 1988, 1991, 1992 a, b, c, 2004; Genzano et al., 1991) and of relatively deep areas of the continental shelf (Boury-Esnault, 1973; Mothes-de-Moraes & Pauls, 1979). In spite of recent advances in the supraspecific taxonomy of Porifera (Hooper & Van Soest, 2002), relatively few revisions exist on species recorded for the Southwest Atlantic Ocean (see Van Soest & Hooper, 1993; Hajdu & Desqueyroux-Faúndez, 1994; Desqueyroux-Faúndez & Van Soest, 1996). Several authors have discussed the biogeographi-cal traits of the sponges inhabiting the Magellanic Province (Sarà, 1992), the Strait of Magellan (Pansini & Sarà, 1999), Chile (Desqueyroux & Moyano, 1987) and Antarctica (Sarà et al., 1992), but a biodiversity analysis of the marine Porifera of Argentina is still lacking. Therefore, the aim of this study was to pro-vide a synthesis of the current knowledge of the marine sponges in the Southwest Atlantic be-tween 35º S and 56º S, and to discuss whether biodiversity patterns can be recognized along the coast and continental shelf of Argentina.
Resumen This article is a review of pollen studies from stratigraphical sequences of Pleistocene and Holocene age with the aim to reconstruct changes in the different types of vegetation and, by inference, of paleoclimatic conditions between 46º and 52º S (Argentina). The paleoenvironmental interpretation is based on comparison of the fossil pollen data with modern pollen data and their relation to the vegetation and the climatic conditions of the study area. Most of the records are of postglacial (Holocene age), only two sequences represent the Middle and Late Pleistocene; the former from the upper valley of the Santa Cruz River and the latter from the area of the Straits of Magellan. Due to the different stratigraphical and sampling resolution of the sequences, the vegetational changes are not evident in all the records. However, the comparison of the sequences at regional scale permitted to evaluate the response of the plant communities to the climate change. The history of the vegetation inferred from these records reflects different processes such as climate change, forest dynamic and human impact. From the interpretation of the available records, the presence of a vegetation without modern analogues is found during the Middle Pleistocene represented by forest dominated by Podocarpus and during the Late Glacial with its dry steppe. Modern vegetation became established at the beginning of the Holocene with the expansion of open forests of Nothofagus. Modern vegetation distribution only developed during the Late Holocene.
Resumen Botryogen (Mg Fe³⁺ OH (SO4)2 7H2O) from Santa Elena mine, San Juan Province, Argentina. Idiomorphic crystals of botryogen from Santa Elena mine, Calingasta, San Juan province, Argentina were studied. Botryogen (Mg Fe ³⁺ OH (SO 4) 2 7H 2O) is monoclinic, Prismatic class (2/ m), space group P 2 1/ n, a = 10.481(1), b = 17.828(1), c = 7.125(1) Å, b = 100°15’(LO), a: b: c = 0.5879:1:0.3997, cell volume 1310.10 Å ³, z = 4. Translucent crystals, transparent in small fragments, red orange color, streak pinkish yellow, vitreous luster, short prismatic crystals elongated along c, measuring till ½ cm. The predominant forms are a {100}, b {010}, m {110}, l {120}, d {101}, o {101}, p {011} and n {111}. The strogest peaks in the X-ray poder diagram are in Å: 8.88 (100), 4.076 (46), 5.121 (38), 6.301 (31), 3.752 (27), 3.012 (25), 2.741 (23), 3.191 (22), 3.509 (20). Botryogen is biaxial (+), a = 1.522(1), b = 1.530(1), g = 1.581(1), Na light, 2 V = 40°, X = b, Z Ù c = 10°, pleochroism X = yellowish white, Y = pale yellow, Z = reddish yellow, r > v strong, cleavages {010} perfect and {110} good, fragile, hardness 2 1/2, density 2.132 (meas.) and 2.106 (calc.) g/cm ³.
Resumen The Triassic flora of Cajón Troncoso, Cordillera del Maule, 7th Region, Chile. Six fossil leaf taxa and one seed from an outcrop in the high andean range at the Maule region, Chile, are described. This assemblage is composed of: Asterotheca sp., Cladophlebis kurtzii Frenguelli vel Cladophlebis mesozoica Frenguelli, Cladophlebis cf. copiosa Frenguelli, Dictyophyllum (Dictyophyllum) tenuifolium (Stipanicic & Menéndez) Bonetti & Herbst, Pterophyllum azcaratei Herbst & Troncoso, Linguifolium lilleanum Arber and Semina incertae sedis. Additionally, fragments of Dicroidium, Heidiphyllum and Rochipteris have also been found. This association allows us to assign a Triassic age to the beds. These sediments were included by earlier authors in the non-formal "Estratos del Cajón Troncoso". Relations of this taphoflora to other Triassic taphofloras from Chile and Argentina are briefly discussed.
MCF-PVPH 53 humerus. A) cranial, B) caudal, C) proximal, D) lateral, and E) medial views. Abbreviations: cd. coracobrachial depression, ct. caudal tuberosity dc. deltopectoral crest, gt. greater tubercle, hh. humeral head, mt. medial tuberosity. Scale bar 2 cm. 
Humeral proximal halves of several abelisauroids in caudal view. A) MCF-PVPH 53, B) Masiakasaurus (from Carrano et al., 2002), C) Carnotaurus (MACN-CH 894) and D) Aucasaurus (from Coria et al., 2002). Not to scale.
Humeri of several abelisauroids in proximal view. A) MCF-PVPH 53, B) Masiakasaurus (from Carrano et al., 2002) and C) Carnotaurus (MACN-CH 894). Not to scale.
Here we describe a partial humerus of a medium-sized theropod dinosaur from the Upper Cretaceous (Late Turonian -Early Coniacian) Portezuelo Formation, Neuquén Province, Argentina. The humerus shares with Abelisauroidea and Elaphrosaurus an articular head proximally oriented, and deltopectoral crest strongly reduced. The bone is referred to Abelisauroidea on the basis of the following derived features: proximal tuberosity on caudal surface of humeral shaft, and greater tubercle at level with the medial tuberosity. The gracile morphology of the humerus, as well as the poor development of its medial tuberosity, resemble more Masiakasaurus than the condition present in abelisaurids (e.g., Carnotaurus, Aucasaurus), in which the humerus is more robust and the medial tuber-osity is prominent. Available information demonstrates that during deposition of the Portezuelo Formation large and bulky abelisaurids (e.g., Ekrixinatosaurus) lived together with gracile and medium-sized abelisauroids. Abelisauroids constitute a group of predatory dinosaurs that were highly diversified and widely dispersed in Gondwana during the Cretaceous (e.g., Bonaparte, 1986; Sereno et al., 2004). Abelisauroidea is usually splited into two clades (Bonaparte, 1991): the small to medium-sized noasaurids, including Noasaurus, Masiakasaurus, Laevisuchus and Deltadromeus (Carrano et al., 2002; Sereno et al., 2004), and the medium to large-sized abelisaurids represented, among others by Rugops, Carno-taurus, Abelisaurus, Ekrixinatosaurus, and Aucasaurus (Bonaparte, 1985; Bonaparte & No-vas, 1985; Bonaparte et al., 1990; Coria et al., 2002; Calvo et al., 2004a; Sereno et al., 2004). The theropod record of the Upper Cretaceous Portezuelo Formation (Late Turonian-Early Coniacian; Leanza et al., 2004) currently consists of the abelisaurid Ekrixinatosaurus novasi (Calvo et al., 2004a), the basal tetanuran Megaraptor namunhuaiquii (Novas, 1998; Calvo et al., 2004b), the maniraptoran alvarezsaurid Patagonykus puertai (Novas, 1997), two yet undescribed coelurosaurians (Coria & Currie, 2002; Porfiri et al., 2005), and the dromaeosaurid maniraptorans Unenlagia comahuensis (Novas & Puerta, 1997), U. paynemili (Calvo et al., 2005), and Neuquenraptor argentinus (Novas & Pol, 2005). Here we describe a partial humerus that constitutes the first non-abelisaurid abelisauroid recorded in the Portezuelo Formation. This new find improves our knowledge of the humeral mor-phology of basal abelisauroids.
The paper makes out a strong case for determine chromatic aberrations that affect the coloring of the birds in the ornithological collection of the Museo Argentino de Ciencias Naturales de Buenos Aires. These alterations are due to excess or deficiency in the production and/or deposition of melanin pigment, the affect families belong to Tinamidae, Spheniscidae, Ardeidae, Threskiornithidae, Anatidae, Falconidae, Rallidae, Charadriidae, Columbidae, Strigidae, Momotidae, Furnariidae, Mimidae, Motacillidae, Emberizidae and Icteridae. Within the proposed changes, the partial leucism (40,5 %) is the most numerous, followed by pastel dilution (23,8 %), albinism (14,3 %) and finally brown aberrations, ino and partial eumelanism, each one of then had (7,1 %).
The Attini, mainly the genera Atta Fabricius and Acromyrmex Mayr, are called leaf-cutting ants. Acromyrmex has scarce records referring to the geographical distribution of its species in Buenos Aires province. The objective of the present work was to gather existing information, to update these data with our own investigation, and to apply different criteria to establish relations with the use of the land. Of the total records for the province, 87 localities of 56 provincial districts were counted. To perform a hierarchical classification of similarities in the distribution patterns of the species, binary data matrices were constructed, analyzed by the weighted average method, calculating squared euclidean distances. The cophenetic indexes obtained were 0.883 for the geographical subregions, 0.943 for the municipal conglomerates and 0.877 for the agricultural areas. Eleven species of ants of the genus Acromyrmex are present in the province of Buenos Aires: A. ambiguus, A. fracticornis, A. heyeri, A. hispidus, A. hystrix, A. landolti, A. lobicornis, A. lundii, A. rugosus, A. silvestrii and A. striatus. The genus Acromyrmex is characterized by nesting in the soil, whereby anthropic practices for productive, industrial and urban purposes directly affect its pattern of occurrence. © 2017 Museo Argentino de Ciencias Naturales Bernardino Rivadavia.
Steps for preparing a palynological slide with UVcurable acrylates. Steps 2-3 should be repeated one or two times. 1. Aqueous palynological suspension. 2. Decanted organic matter. 3. Palynological residue suspended in ethanol. 4. Decanted organic matter. 5. Mounting media resting on the microscope slide. 6. Organic matter mixed with the mounting media. 7. Exposure to U.V. 
Acrylates used as mounting media.
Measurements made with light microscope at 100X. Error ± 1 µm.
UV-curable acrylates are used as an easy, economic and rapid mounting media to mount palynological samples. The aqueous palynological residue is dehydrated with ethanol in order to be set in UV-curable acrylates such as Trabasil ® NR2 and Acrysoft ® urethane acrylates. These mounting medias have advantages over other ones: specimens remain in fixed position, and/or they are not attacked by any organism or modified by any environmental conditions such as humidity and heat. In addition refraction index is similar to that of sporopollenin and glass which provides an excellent interfase to discern fine morphological features.
The Pampas region (Argentina) have suffered profound changes in the agroecosystems as a result of many pollutants generated by agricultural and livestock activities. The objective of this study was to evaluate the water quality of a microbasin belonging to the Burgos stream (San Pedro, Province of Buenos Aires) through the application of water quality indexes (ICAs), faecal contamination indicators and algae bioassays. Three samplings were carried out in 2015 and six sampling sites were selected, four along the tributary stream of order 1, and two in the stream. Two ICAs were used: ICA 1 , whose variables were temperature, OD and NH 4⁺ , and ICA 2 , whose variables were pH, OD, temperature, nitrates, PRS and faecal coliforms. According to the ICA 1 , water quality ranged from slight to very high pollution, and according to the ICA 2 , from regular to dreadful quality. The concentration of faecal indicators microorganisms was similar in all the samples, while significant differences were observed in the concentrations of Salmonella spp. According to the correlation analysis, precipitation would participate in the transport of coliform microorganisms to surface waters through surface runoff processes. On the other hand, the inhibition of algal growth would not be related to glyphosate, whose concentrations were between 0.35 and 13.57 μg/L. The results suggest that the application of different indicators could be a very useful tool to evaluate the environmental quality of surface waters from the Pampas plain, in particular the use of indexes including coliform microorganisms in the calculation equation. © 2018 Museo Argentino de Ciencias Naturales Bernardino Rivadavia.
ubicación geográfica de la reserva Provincial Loro Hablador en la provincia del chaco.
A. Macho. cabeza y tórax de O. toledoi morfo típico (a). B. Idem. Pigóforo y últimos segmentos abdominales. C. Macho. cabeza y tórax de O. toledoi morfo b. D. Idem. Pigóforo y últimos segmentos abdominales. E. Hembra. Últimos segmentos abdominales. Escalas: A y c 0,5 mm, B, d y E 0,25 mm.  
The primary natural host of cimicid bug Ornithocoris toledoi Pinto (Hemiptera: Heteroptera: Cimicidae) is presented as Blue- Crowned Parrot Aratinga a. acuticaudata (Aves: Psittacidae). Its presence in the Chaco province is also a new distributional record of this bug in Argentina. A brief discussion about the taxonomy is also given and some population parameters are compared with those of other bug species. Finally, we discuss possible infestation ways in the current state of knowledge, including other birds (Furnariidae) and bats (Chiroptera).
Área de estudio con detalle de los sitios de muestreo en las cuencas de los arroyos La choza y El durazno.  
riberas sujetas a distintos impactos. A: riberas en buen estado de conservación con vegetación predominantemente nativa aguas arriba del alambrado (tramo c0). B: riberas sujetas a invasiones biológicas (G. triacanthos) e ingreso de efluentes de industria avícola (Ec1) desde la margen izquierda (fotografía tomada desde el puente Irigoyen, tramo c2).  
Valores medios de los índices IcA e IcAP (arriba ) e IcrP (abajo) calculados para distintos sitios de las cuencas de los arroyos La choza y El durazno.  
The aquatic environments of the Pampas (Argentina) are subject to increasing human pressures, such as the dumping of domestic and industrial wastewater. Eight river samplings were conducted in the period 2010-2013 taking surface water samples at several locations of La Choza and El Durazno streams (Reconquista River basin, Buenos Aires) and in channels receiving agroindustrial effluents (chicken and pig farms). Two new indexes were adapted and applied: Water Quality Index of the Pampas Streams (ICAP) and Quality Index of the Pampas Riverbanks (ICRP). The variables used for the calculation of ICAP were total suspended solids (TSS), ammonium nitrogen (N-NH4⁺), total phosphorus (TP), BOD5 and dissolved oxygen (DO). Also, Water Quality Index (ICA) was calculated. ICRP was developed based on Riparian Quality Index (QBR). The discharge of wastewater from the poultry industry contributed to increased concentrations of TSS, N-NH4⁺, TP and BOD5. The mean values of the ICA and ICAP were low and similar, although ICAP was more effective to identify extreme water quality cases. The main factors that reduced the value of the ICR P were the absence or low abundance of marsh grasses, the presence of exotic and invasive plant species and the existence of channel crossing structures. The results suggest that the use of both indexes is a useful alternative in the environmental assessment in the Pampas streams.
Resumen The new genus and species Litocalliopsis adesmiae is described from the province of Buenos Aires, Argentina. The phylogenetic relationships of the new genus are discussed, suggesting that it is the sister group of the broadly distributed genus Calliopsis Smith. Descriptions and illustrations of the new taxon, and a key to separate Litocalliopsis from other calliopsine genera, are presented. A nesting area of the species was studied, and the biological features of the species are described and compared to those of other calliopsines. Such features are adult activity, nest architecture, cell structure, shape and position of provisions, egg placement, mating behavior, and plants visited. These bees collected pollen from the legume Adesmia bicolor (Poir.) D.C. The postdefecating larva is also described and illustrated.
Resumen Unilocular calcareous Foraminifera of the middle-upper Eocene and lower Oligocene from Tierra del Fuego Island and adjacent continental platform, Argentina. The calcareous unilocular Foraminifera of the Leticia Formation (upper middle Eocene), Cerro Colorado Formation (upper middle Eocene-upper Eocene) and the Cabo Peña Formation (lower Oligocene) from Tierra del Fuego Island are described. The Leticia Formation yields scarce unilocular foraminifers that are characterized by species described from the Maastrichtian and the lower Eocene, including Conolagena argentina, C. acuticosta and Sipholagena sp. The Cerro Colorado Formation bears 29 species, almost the half of which (both individuals and species) belong to the Genus Fissurina, with Fissurina bisulcata occurring as the most abundant taxon. The formation also contains species characteristic of either Antarctic waters or the Malvinas current, reflecting the temperature decrease in the oceanic waters during the middle-late Eocene. The Cabo Peña Formation, which contains the Spirosigmoilinella-Martinottiella Assemblage typical of the Antarctic region, yielded 19 species; the dominant unilocular species belong to the genera Fissurina and Parafissurina, and the most conspicuous are fimbriate forms, such as F. fimbriata and F. fueguina, which are associated with Antarctic waters.
This paper includes the first reference to Podranea ricasoliana and new records of Campsis radicans (Bignoniaceae) for the adventitious Argentinean Flora. Also includes observations on the expansion mechanisms and the status into the naturalization process for P. ricasoliana, besides a key to differentiate the adventitious Bignoniaceae in Argentina.
Resumen New records of adventitious monocots for Argentina. This paper includes five new records of adventitious monocots for Argentina: Aloe ciliaris Haw. (Asphodelaceae), Aspidistra elatior Blume (Convallariaceae), Sansevieria trifasciata Prain (Dracaenaceae), Phormium tenax J. R. Forst. & G. Forst. (Hemerocallidaceae) and Ornithogalum arabicum L. (Hyacinthaceae), belonging to order Asparagales. Also includes an evaluation of its status in the naturalization process: casual alien, naturalized.
This paper includes five new records of adventitious monocots for Argentina: Aloe ciliaris Haw. (Asphodelaceae), Aspidistra elatior Blume (Convallariaceae), Sansevieria trifasciata Prain (Dracaenaceae), Phormium tenax J. R. Forst. & G. Forst. (Hemerocallidaceae) and Ornithogalum arabicum L. (Hyadnthaceae), belonging to order Asparagales. Also includes an evaluation of its status in the naturalization process: casual alien, naturalized.
This paper includes the first record of Wisteria sinensis (Leguminosae) adventitious in Argentina, observations on its mechanisms of expansion and its status in the context of the naturalization process.
This paper includes two adventitious species of the genus Parthenocissus Planch. in Argentina: P. tricuspidata (Siebold & Zucc.) Planch. and P. quinquefolia (L.) Planch., both introduced as ornamentals. Descriptions, synonymy, iconography, distribution, common names, uses, keys and reference material are given. Also contains observations about its climb strategies, its expansion mechanisms, and its actual status in the context of naturalization process.
Resumen First reference of Parthenocissus tricuspidata and new record of P. quinquefolia (Vitaceae) adventitious in Argentina. This paper includes two adventitious species of the genus Parthenocissus Planch. in Argentina: P. tricuspidata (Siebold & Zucc.) Planch. and P. quinquefolia (L.) Planch., both introduced as ornamentals. Descriptions, synonymy, iconography, distribution, common names, uses, keys and reference material are given. Also contains observations about its climb strategies, its expansion mechanisms, and its actual status in the context of naturalization process.
Mapa mostrando las localidades de los perfiles de la Cuenca Austral donde fueron halladas las esporas estudiadas o citadas: 1) Lago Cardiel, Cerro Bayo; 2) Bajo Comisión; 3) Kachaike; 4) El Quemado (perfil El Moro); 5) Perforaciones del área Magallanes-Gallegos; 6) Anfiteatro de Ticó.  
Abstract: Aequitriradites Delcourt & Sprumont and Couperisporites Pocock liverwort spores from the Early Cretaceous of Patagonia, Argentina. Spores belonging to liverworts are common components of Early Cretaceous assemblages in Southern Patagonia. Two genera, Aequitriradites and Couperisporites were identified from several localities and offshore wells in the Austral Basin. Three new species of Aequitriradites , viz. A. plicatus, A. longispinosus and A. superpinulosus are defined, together with the known species A. spinulosus, A. verrucosus and A. baculatus. Couperisporites is described and illustrated for the first time in Argentina with two species, viz. C. lilianae n.sp. and C. sp. Considerations on some morphological aspects related to ornamentation and exine structure are made as well as some stratigraphic implications on the distribution of these taxa. The taxonomic variety suggests favourable temperate/warm and humid environmental conditions for development of liverworts during the Early Cretaceous in Patagonia in agreement with data provided by other plant groups identified in the same assemblages Aequitriradites Delcourt & Sprumont and Couperisporites Pocock liverwort spores from the Early Cretaceous of Patagonia, Argentina. Available from: [accessed Oct 26, 2016].
Resumen Fossil woods with Araucariaceae affinity from the Bajo Barreal Formation, Late Cretaceous of central Patagonia (Argentina). Fossil woods collected from sediments of the Late Cretaceous Bajo Barreal Formation (Patagonia, Argentina) are described and assigned to the morphogenus Agathoxylon. The woods have weakly marked growth ring boundaries, uniseriate to rarely biseriate radial pitting, with contiguous circular to hexagonal bordered pits, alternate when biseriate. Rays are uniseriate and low, usually with up to 5 cells in height. Cross-field pits are not very well preserved; they seem to be elliptical and oblique and 3-5 per cross-field. The woods are anatomically similar to extant South American species of Araucaria and to several fossil species, particularly Agathoxylon matildense. They corroborate the abundance of Araucariaceae in Late Cretaceous and become the first description of macroflora for the formation.
Top-cited authors
Fernando E Novas
  • Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"
Federico Agnolin
  • Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"
Leopoldo Soibelzon
  • Universidad Nacional de La Plata
Sergio Archangelsky
  • Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"
H. A. Leanza
  • Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"