Revista del Museo Argentino de Ciencias Naturales

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.

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.

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.

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 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.

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.