Synthèse de trithioorthocarbonates de pyranosides par thermolyse de bis(dithiocarbonates)

The thermal decomposition of methyl 4,6-O-benzylidene-2,3-di-O-[(methylthio)-thiocarbonyl]-α-d-glucopyranoside afforded methyl 4,6-O-benzylidene-2-thio-α-d-mannopyranoside 3-O,2-S-(S,S-dimethyl trithioorthocarbonate) and methyl 4,6-O-benzylidene-3-thio-α-d-allopyranoside 2-O,3-S-(S,S-dimethyl trithioorthocarbonate) in good yield. This decomposition can be generalized to 1,3-diols derived from sugars. Thus methyl 2,3-di-O-methyl-4,6-di-O-[(methylthio)thiocarbonyl]-α-d-glucopyranoside afforded in the same way the corresponding trithioorthocarbonates, following a regioselective process. The structures of these trithioorthocarbonates are confirmed by spectral and chemical proofs.     

Reflexions sur l'usage,en biologie,de la theorie de l'information

For living beings, information is as fundamental as matter or energy. In this paper we show: a) inadequacies of quantitative theories of information, b) how a qualitative analysis leads to a classification of information systems and to a modelling of intercellular communication. From a quantitative point of view, the application in biology of information theories borrowed from communication techniques proved to be disappointing. These theories ignore deliberately the significance of messages, and do not give any definition of information. They refer to quantities, based upon arbitrarily defined probabilistic events. Probability is subjective. The receiver of the message needs to have ‘meta-knowledge’ of the events. The quantity of information depends on language, coding, and arbitrary definition of disorder. The suggested objectivity is fallacious. In common language, the word ‘information’ is synonymous with knowledge of order. Following common sense a message (letters, coded signals, etc.) is information just in case it is interpretable, i.e.if it fits to a previously acquired meaning (the words of an available language, etc.). The consequence is that calculation of quantities in the sense of Shannon can be used for transmissions, but it is itself meaningless (has no significance). In linguistics and semantics, information is composed of a ‘signifier’, a physical medium (letters, coded signals, etc.), and a ‘signified’ or significance. The nature of information is complex. The laws of linguistics and semantics are valid not only at the human, organismic level, but also at the cellular and molecular level. The physiology of sensations gives us many examples for application of a concept of information An electromagnetic wave of 0,7% give us the sensation of a red colour. Sensations have no physical reality. They are purely subjective. At the cellular level communication operates by means of chemical messengers (first messengers), which generally do not penetrate the plasmic membrane. Specific captors operate as transductors: external factors are converted into secondary messengers (cyclic AMP, Ca ion, etc.). Sometimes, electric signals (like depolarization waves) may also play a part in the intercellular communication. Such processes are characterized by changes in a sequence of different molecules carried by a physical signal. What is transmitted is themeaning of the message (significance) which can be memorized by the cell, providing a possible following use. At the molecular level one can find also the processes of linguistic nature. We know that the significance of a word is changed with changing the order of letters (ADD→DAD, etc.). In the same way bases C and U are coding for serine (UCC), leucine (CUC) or proline (CCU). Here, amino-acids express the significance. In spite of the fact that this key-lock mechanism may explain many reactions, the examples prove that other elements are necessary for understanding the information. The living cell is the receiver. The message actualizes only previously learned and memorized significances or actions (trigger effect). Significance is not an emergent property of the shape of the message. It depends on the receiver and the transmitter. A word can have more than one meaning. Similarly, a messenger can order different physiological responses: muscular tension, hormonal secretion, etc.. Thus a chemical messenger is a signal which is identified and interpreted by the receiver, depending upon specific languages and previous learning. These views are in harmony with immunological and Jerne's theory (of idiotypical net). The above mentioned considerations led the author to propose thetheory of data transfer, which takes into account significance. In this theory the quantity of information is the product of the probabilistic recognition of message and the value of significance as determined by its semantic level. (See: Acta biotheoretica vol. 41 No 1/2 June 1993.) The complex nature of information asks to propose a qualitative classification with respect to thematerial support and thesignificance.

1. The material support may be linear in time (sequential reading, ADN translation)-The material support may be referred to non-temporally (drawings, logos, holograms) (Reading is instantaneous)-The material support may be in circulation, or in stock.
2. The significance may be local (tissues, organs) or general (organisms). Asignificance may be a command to be executed (imperative, conditional order) or knowledge to bememorized. The purpose of significance may be a coding for space (for morphology) or for time (ontogeny, ageing).

Conclusion: Information cannot any longer be regarded as an object. Its nature is complex, at all levels of a living being. At the molecular level to memorize an information by modification of a molecule is comparable with writing words on a diary. The key-lock process does not suppress the question of the interpretation, i.e. relations existing between the shape of a microscopic element as a molecule, and its macroscopic effect, as an antenna or a leg. There are still many unclear points in these relations, e.g. the sweet taste of molecules of tomatine and monelline. The abstract nature of significance which at the human level is concerned to mental processes, is not only a philosophical problem. In fact, there is a hypothesis based on quantum mechanics which allows to consider a physical nature of significance. In any case, the important conclusion is that significance in bio-information must be considered in relation to the message-receiver. The receiver must no longer be considered a passive one. The qualitative classification of information will allow an understanding of circulation of information in organisms and between cells.     

Estudio paleoecológico de Foraminíferos de testigos del Holoceno de Golfo Nuevo (Patagonia, Argentina)

A micropaleontological study (Order Foraminiferida) was conducted on two Holocene cores from Golfo Nuevo (Patagonia, Argentina). The most abundant species are Buccellaperuviana f. campsi (Boltovskoy) and Bulimina patagonica (d’Orbigny), suggesting an inner-shelf environment. Qualitative and quantitative analyses indicate the paleoecological and paleoenvironmental variations along cores. A transition from normal marine conditions of the inner shelf during the Middle Holocene (ca. 8160-7700 years B.P.) to marginal marine conditions in the Late Holocene (ca. 1890 years B.P.) is inferred. This transition was accompanied by lower oxygen levels than the current values in Golfo Nuevo. These variations may have been due to an increase in precipitation near the study zone and a rise in sea level caused by an improvement in the climatic conditions related to the Climate Optimum (ca. 7000 years B.P.). These new conditions of higher temperature and lower salinity of the surface waters may have hindered deep-water renewal, producing a change in the circulation dynamics of the gulf and causing a reducing environment.     

Corymboside,nouvelle di-C-glycosylflavone des racines de Carlina corymbosa

Corymboside, a new di-C-glycosylflavone from Carlina corymbosa roots, was shown to be 6-C-α-l-arabinopyranosyl-8-C-β-d-galactopyranosylapigenin by MS, CD, ¹H and ¹³C NMR.     

Papel de la genética en la etiología de las sinucleinopatías

The protein family known as synucleins is composed of α-, β- and γ-synuclein. The most widely studied is the α-synuclein protein due to its participation in essential processes of the central nervous system. Neurotoxicity of this protein is related to the presence of multiplications (duplications and triplications) and point mutations in the gene sequence of the α-synuclein gene (SNCA), differential expression of its isoforms and variations in post-transductional modifications. Neurotoxicity is also related to cytoplasmic inclusions known as Lewy bodies (LBs) and Lewy neurites (LNs), which are also present in α-synucleinopathies. In general, the β-synuclein protein, codified by the SNCB gene, acts as a regulator of processes triggered by α-synuclein and its function is altered by variations in the gene sequence, while γ-synuclein, codified by the SNCG gene, seems to play a major role in certain tumoral processes.     

Syntheses stereoselectives de 1-thioglycosides

2,3,4,6-Tetra-O-acetyl-β-d-mannopyranosyl chloride (2) was obtained in 70% yield by the action of lithium chloride on 2,3,4,6-tetra-O-acetyl-α-d-mannopyranosyl bromide (1) in hexamethylphosphoric triamide. p-Nitrobenzenethiol reacted with 1 and 2 as well as with 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl bromide (9) or its β-d-chloro analog (10), giving exclusively and in good yield the corresponding p-nitrophenyl 1-thioglycosides of inverted anomeric configuration. The 1,2-cis-d-manno and -glucop-nitrophenylglycosides were likewise prepared. α-d-Glucopyranosyl 1-thio-α-d-glucopyranoside was similarly obtained by the action of the sodium salt of 1-thio-α-d-glucopyranose on the β-chloride 10 in hexamethylphosphoric triamide, or by treatment of 10 with sodium sulfide, with subsequent deacetylation. Analogous procedures allowed the preparation of β-d-mannopyranosyl 1-thio-β-d-mann opyranoside, the corresponding α,β anomer and α-d-glucopyranosyl 1-thio-α-d-mannopyranoside, starting from bromide 1, 1-thio-α-d-mannopyranose (8),and chloride 10, respectively. When acetone was used as solvent, the reaction between 1 and 8 led instead to the α,α anomer. The thio disaccharides that are interglycosidic 4-thio analogs of methyl 4-O-(β-d-galactopyranosyl)-α-d-galactopyranoside, methyl α-cellobioside, and methyl α-maltoside, respectively, were obtained by way of the peracetates of methyl 4-thio-α-d-galactopyranoside and -glucopyranoside by reaction of the corresponding thiolates with tetra-O-acetyl-α-d-galactopyranosyl bromide, bromide 9, or chloride 10, respectively, in hexamethylphosphoric triamide. These 1-thioglycosides, and (1→1)- and (1→4)-thiodisaccharides, were characterized by ¹H- and ^{1 3}C-n.m.r. spectroscopy. Correlations were established between the polarity of the sulfur atom and certain proton and carbon chemical-shifts in the 1-thioglycosides in comparison with the O-glycosyl analogs; these correlations permitted in particular the unambigous attribution of anomeric configuration.     

Malacofauna Cuaternaria del litoral norte de Santa Cruz (Patagonia, Argentina)

The molluscan content from three “marine terraces” (TM) preserved along 250 km of the Santa Cruz province provided 49 molluscan taxa (33 Gastropoda and 16 Bivalvia) and the first Quaternary records for Ataxocerithium pullum, Crepidula protea, C. aculeata, Adelomelon ferrusacii, Brachidontes rodriguezi, Aequipecten tehuelchus, Ostrea tehuelcha, and Solen tehuelchus. The mollusca assemblages suggest typical marine nearshore conditions similar to the adjacent modern littoral (Southwestern Atlantic), with mostly hard substrates, shallow and cold waters. The TMVI (+ 5-15 m a.s.l., ca. 8-1.2 ka A.P.) is mainly characterized by dominance of Brachidontes spp., Nacella spp. and Mytilus edulis, associated with Siphonaria lessoni. No evidence has been found for the TMVI of clear biotic responses or strong palaeobiogeographic effects during the time span of the Climatic Optimum (“Hypsithermal”, mid-Holocene) which has been documented for other coastal areas northward in Argentina, down to ca. 44-45° S. Scarce differences distinguish the TMV (+ 15-30 m a.s.l., ca. 108-137 ka A.P., MIS5?) and TMIV (+ 20-30 m a.s.l., ca. 242 ka A.P.) regarding the Holocene and the modern littoral. Within the TMV, Clausinella, Eurhomalea, Solen tehuelchus and Brachidontes cf. darwinianus (typically in warmer waters) are exclusive; in the TMIV, Trophon, Buccinanops, Brachidontes and Pectinidae are characteristic. Predominance of Trophon spp. (typically in cold Magallanic waters) in modern samples vs. scarcity or absence in the TM suggest slightly lower modern SST. Several taxonomic similitudes with the Pacific Sudamerican coast (e.g., Fissurella,Nacella, Tegula, Crepidula, Trochita, and Acanthina) could respond to cold currents helping cold-water immigrants to join southern Southamerican Atlantic after the opening of the Drake Passage.     

Lanveocia et Candelasphaeridium,genres nouveaux d'Acritarches des gres de Landevennec (Gedinnien inferieur de la rade de Brest - Finistere)

Two new genera of organic-walled microplancton (Acritarchs) are described. All are from the Early Devonian(Early Gedinnian) Grès de Landévennec (Rade de Brest - Finistère). Lanveocia formosa (type species) and Candelasphaeridium insolitum (type species) are described.     

La unidad de ortogeriatría de agudos. Evaluación de su efecto en el curso clínico de los pacientes con fractura de cadera y estimación de su impacto económico

Objective

To study the effects of the management of hip fracture patients in an acute orthogeriatric unit shared between the departments of Orthopedic Surgery and Geriatrics compared with the usual hospital care, and to analyse financial differences in both systems of care.

Method

Prospective quasy-experimental randomized intervention study in 506 patients admited to a terciary hospital with an osteoporotic hip fracture. The usual model of care was the admission to the orthopedic ward with a request to Geriatrics (RC) and the study model consisted of the admission to an orthogeriatric unit (OGU) for the shared co-management between orthopaedic surgeons and geriatricians. This model included the appointment of one spokesperson from each department, the specialist geriatric nurse management, early geriatric assessment, shared daily clinical care, weekly joint ward round and coordinated planning of the surgery schedule, the start of the ambulation and the time and setting of patient discharge.

Results

Two hundred fifty five consecutive patients admitted to the OGU and 251 patients managed simultaneusly by the RC model were included. Except for a mean age slightly lower in the OGU group, there were no differences neither in the baseline patients characteristics nor in the surgical rates between the two groups. Among the OGU patients group it was more frequent to receive rehabilitation in the acute setting, to be able to walk at discharge and to be referred to a geriatric rehabilitation unit (all with P<.05). The OGU patients received geriatric assessment and were operated on earlier than the RC patients (P<.001). The length of stay in the acute ward was 34% shorter in the OGU patients (mean 12.48±5 vs 18.9±8.6 days, P<.001) (median 12 [9-14] vs 17 [13-23] days, P<.001). The whole hospital length of stay, including the days spent in the geriatric rehabilitation units, was 11% shorter in the OGU patients (mean 21.16 ±14.7 vs 23.9 ±13.8 days, P<0.05) (median 14 [10-31] vs 20 [14-30] days, P<.001). The OGU saved 1,207 € to 1,633 € per patient when estimated by the costs for process model, and 3,741 € when estimated by the costs for stay model.

Conclusions

The OGU is a hospital setting that provides an improvement in the patients functional outcome and a reduction in the hospital length of stay. Therefore it saves health care resources. These findings show the OGU as an advisable setting for the acute care of hip fracture patients.     

Una nueva especie de Pachynolophus (Mammalia, Perissodactyla) de Zambrana (Álava, Región Vasco-Cantábrica). Análisis filogenético de Pachynolophus y primera cita en el Eoceno superior de la Península Ibérica

Recent fieldwork in the Late Eocene of Zambrana (Álava, Basque-Cantabrian Region) has yielded a new species of Pachynolophus: P. zambranensis nov. sp. According to the phylogenetic analysis made in this study, the Zambrana species is part of the monophyletic Pachynolophus, which is defined at least by three synapomorphies: significant progressive increase of the size in the M1/1-M3/3 series, being M3/3 outstandingly bigger than M2/2; moderate increase of the relative surface of M3/ with respect to M2/ surface, and weak labial cingula in the lower series. Pachynolophus includes the species P. duvali, P. livinierensis, P. garimondi, P. lavocati, P. zambranensis, P. boixedatensis and P. cesserasicus. P. molipotensis and P. cayluxi are not represented by sufficient material to attribute them to Pachynolophus. P. bretovensis does not share a synapomorphy of Pachynolophus and P. hookeri should not be referred to this genus. P. zambranensis shares several synapomorphies with P. garimondi and P. lavocati, which are: the posprotocrista of the P3-4/ series is a well-defined lophe; the P4/ has a subquadrangular outline and shows a strong posterolingual cingulum, forming a posterior widening; and there is an “incipient mesostyle” (pseudomesostyle?) in the upper molars. The species P. zambranensis is mainly characterized by lophodont dentition, with the postprotocrista obliquely oriented to the ectoloph in the P3-4/ series, and a “pseudomesostyle” also present in the P3-4/ series. It represents the first mention of the genus Pachynolophus described in the Late Eocene of the Iberian Peninsula.     

Le gisement de Freiria de Rio Maior,Portugal, et sa faune de Mammiferes; Nouvelle espece de Rotundomys,consequences stratigraphiques

A new locality, close to Freiria de Rio Maior, provided a mammalian fauna associated with Charophytes, secds,Ostracods, Gastropods and Urodels. The most abundant remains correspond to a new species: Rotundomys freiriensis. This fauna has been dated as the Upper Vallesian base (MN 10), corresponding to the most recent level with small mammals found in the portuguese Miocene. Thus, the Freiria limestone succession is correlated to Cartaxo, Almoster, etc., limestones which are so developed in the Ribatejo area.     

Identification des constituants de l'essence des aiguilles de Pinus pinaster

The chromatographic analysis of the volatile leaf oil of Pinus pinaster Ait. showed 42% of monoterpene hydrocarbons (α-pinene, camphene, β-pinene, myrcene, 3-carene, limonene, cis-ocimene, terpinolene, para-cymene, 35% of sesquiterpene hydrocarbons (cubebene, copaene, caryophyllene, humulene, germacrene D, α- and γ-muurolenes, δ- and γ-cadinenes) and 23% of oxygenated compounds including esters (linalyl, bornyl, geranyl, neryl and farnesyl acetates), alcohols (cis-hexenol, linalool, α-fenchol, trans-pinocarveol, terpinen-4-ol, α-terpineol, dihydrocarveol, guaiol, junenol and α-cadinol), one aldehyde (hexenal) and one ketone (piperitone). Three non terpenoid phenylethyl esters were also identified: phenylethyl isovalerate, methyl-2 burtyate and 3-3 dimethylacrylate. Some alcohols and mainly α-terpineol and linalool seemed to be formed during the steam distillation process, they were absent when the leaf oil was obtained by maceration of small portions of leaves in the usual solvents of terpenes.     

Heminautilus sanctaecrucis,nouvelle espece de nautiloïde cretace

A new interpretation of the J.F. Pictet et G. Campiche's Nautilus lallierianus is here proposed. Their specimen canbe separated from Heminautilus lallierianus (d'ORB.) and Heminautilus saxbii (MORRIS). The new designation attributed is Heminautilus sanctaecrucis.     

Charophytes, indicateurs de paléobathymétrie du lac Tigalmamine (Moyen Atlas, Maroc)

A paleolimnological study can be particularly accurate in situations where the species found in the sediments have persisted in the same lake and can provide a direct modern analogue for interpretation. Lake Tigalmamine, thus, represents an exceptionally favourable context, compared to most paleolakes in North Africa, as this site allows comparing the fossil remains of the Characeae to those produced by the living plants. Tigalmamine is a hydrosystem composed of three karstic lakes located at 1626 m above sea level in the Middle Atlas of Morocco. The site had been the subject of a 16 m long core taken in the center of the central lake under 16 m of water (core C 86 in Lamb and Kaars, 1995 [The Holocene 5 (1995) 400-408]). The section represents the total of the Holocene from 10,200 BP to Present (El Hamouti et al., 1991 [Comptes Rendus de l’Académie des Sciences de Paris 2 (1991) 259-265]; Lamb et al., 1995 [Nature 373 (1995) 134-137]). The latter published a synthesis of the pluridisciplinary studies conducted on this core. Also, the numerous gyrogonites isolated from that core had been determined as Chara hispida (Soulié-Märsche in Benkaddour, 1993 [Changements hydrologiques et climatiques dans le Moyen-Atlas marocain : chronologie, minéralogie, géochimie isotopique et élémentaire des sédiments lacustres de Tigalmamine. PhD thesis, Université Paris-Sud, Orsay (inédit)]). Further fieldwork at Tigalmamine by the authors of the present paper in year 2000 showed that Chara hispida is still present in the lake where it forms a belt of submerged vegetation restricted to the range of 2 to 9 m water depth. This paper describes the morphological and ecological characteristics of the extant Chara hispida as a reference for the interpretation of the fossil remains. Based on these data, the frequency changes of the gyrogonites in the core sediments become significant in terms of bathymetry. The detailed analysis of the charophytes from the core, as a complement to the previous studies, confirms the existence of four Holocene phases with lake level low stand at Tigalmamine. The aim of the present study is to enhance the value of the charophytes as a useful complementary tool for paleolimnological reconstruction.     

Etude comparative de la densite de groupes de poissons cavernicoles et epiges (characidae,cyprinidae, clariidae)

The group density of four species of cave fishes (Caecobarbus geertsi, Barbopsis devecchii, Astyanax gen. and Uegitglanis zammaranoi) and of two taxonomically related epigean species (Barbus conchonius and Hyphessobricon scholzei) was measured tridimensionally in an experimental aquarium, using a video recorder and a mirror inclined at 45° placed on top of the aquarium. The experiments were conducted in dim red light. The illumination was continuous in the case of cave fishes. For the epigean forms a 12/12 LD cycle was superimposed using dim achromatic sources. The relative positions of individuals within their own specific group were registered hourly during a week (168 h). Results show that in cave forms, the mean density of groups falls within the theoretical limits of random distribution values in all cases, whereas epigean species display a non-random aggregation tendency.     

Uridylate trapping, induction of UTP deficiency, and stimulation of pyrimidine synthesis de novo by d-galactosone

d-Galactosone (d-lyxo-2-hexosulose) is phosphorylated and metabolized to the uridine diphosphate derivative in AS-30D hepatoma cells and rat liver. These reactions were catalysed in vitro by galactokinase and hexose-1-phosphate uridylyltransferase. Nucleotide analyses by high-performance liquid chromatography and enzymic assays revealed that this galactose analogue interferes with cellular pyrimidine nucleotide metabolism leading to a deficiency of UTP. [¹⁴C]Uridine labelling of hepatoma cells indicated a division of [¹⁴C]uridylate from UTP into UDP-galactosone; the latter was formed at a rate of more than 1.7mmol×h⁻¹×(kg AS-30D or liver wet wt.)⁻¹. As a consequence of UTP deficiency, d-galactosone (1mmol/1 or 1mmol/kg body wt.) strongly enhanced the rate of pyrimidine synthesis de novo as evidenced by incorporation of ¹⁴CO₂ into uridylate and by an expansion of the uridylate pool. This resulted in a doubling of the total acid-soluble uridylate pool within 70min in the hepatoma cells and within 110min in rat liver. Combined treatment of hepatoma cells with d-galactosone and N-(phosphonoacetyl)-l-aspartate, an inhibitor of aspartate carbamoyltransferase, prevented the expansion of the uridylate pool and led to a synergistic reduction of UTP to 10% of the content in control cells. Hepatic UTP deficiency was selective with respect to other nucleotide 5′-triphosphates but was associated with reduced contents of UDP-glucose, UDP-glucuronate, and UDP-N-acetylhexosamines. Isolation of the UDP derivative of d-galactosone revealed an extremely alkali-labile UDP-sugar, probably an isomerization product of UDP-galactosone, that was degraded by elimination of UDP with a half-life of 45min at pH7.5 and 37°C. The instability of UDP-galactosone may contribute in vivo to limit the time period of severe uridine phosphate deficiency in addition to the compensatory role of pyrimidine synthesis de novo. During the initial time period, however, d-galactosone is effective as a powerful uridylate-trapping sugar analogue.     

Asociación entre la realización de ejercicio e indicadores de funcionamiento físico y cognitivo. Comparativa de resultados en función de la edad

Background

Gerontology research shows the importance of physical exercise for active aging. This study demonstrates the relationship between the practice of aerobic exercise, and physical fitness (muscle strength, respiratory capacity and motor speed) and cognitive performance (memory and visual-perceptual speed) and analyzes whether age is a modulating factor of this relationship.

Material and methods

The sample included 690 subjects with an age range of 30-85 years. The level of physical exercise was assessed using self-report form. Two sub-scales were used for the evaluation of cognitive performance: Digit Span Backwards and Digit Symbol (both are sub-scales of the Wechsler Adult Intelligence Scale - WAIS). The physical fitness was assessed using bio-behavioral measurements (strength, lung capacity, speed). To test the combined effect of exercise and age on the two variables (physical fitness and cognitive performance) two separate factorial analysis of variance were performed (procedure - general linear model: Univariate).

Result

The most significant result showed that scores on cognitive performance is a function of the intensity of the physical activity (F=4.8; P<0.002). With regard to physical fitness, its relationship with physical exercise is also significant (F=4.10; P<0.007) as well as the interaction between exercise and age (F=2.2; P<0.001).

Conclusions

The intensity in achieving aerobic exercise is associated with physical fitness and cognitive performance. Age has a specific weight in the association between exercise and physical fitness, this effect is higher in the older age groups (65-74 and 75-85 years for 30-49 and 50-64 years). These data suggest the compensatory effect of exercise on decline in old age.     

Dientes de Theropoda (Dinosauria: Saurischia) de la Formación Bajo Barreal, Cretácico Superior, Provincia del Chubut, Argentina

Theropod teeth from the Bajo Barreal Formation (Upper Cretaceous: Cenomanian-Turonian) at the “estancia Ocho Hermanos”, Chubut Province are described. Most of them show features of Abelisauroidea, a clade already represented in the Bajo Barreal Formation by Xenotarsosaurus bonapartei and other isolated remains including a left maxilla. Dromaeosauridae and Carcharodontosauridae represent the first record of these taxa for the Bajo Barreal Formation. Besides this, at least three theropod clades (Abelisauroidea, Carcharodontosauridae, and Dromaeosauridae) coexisted in central Patagonia during the Cenomanian-Turonian along with other theropods as Aniksosaurus darwini and Megaraptor sp.     

Una nueva especie de Neuryurus Ameghino (Mammalia, Glyptodontidae) en el Pleistoceno tardío de la Mesopotamia de Argentina

Among the South American Pleistocene Glyptodontidae (Xenarthra, Cingulata), one of the most scarcely represented genus in the fossil record is Neuryurus Ameghino, in which the only well characterized species, until now, is Neuryurus rudis (Gervais), coming from the Ensenadan (early-middle Pleistocene) of the Pampean region, Argentina. In this contribution, we report and describe a new species of Neuryurus, coming from the Arroyo Feliciano Formation (early Lujanian; ca. 130 ka), Entre Ríos province, Argentina, in a particular palaebiogeographic context, more associated with the western sector of Uruguay and southern Brazil than the Pampean region. From a morphological perspective, this new taxon is characterized by: (a) the remarkable development of the foramina at the exposed surface of the osteoderms of the dorsal carapace, showing un aspect almost spongy; (b) the large diameter of the perforations observed in the ventral surface of the osteoderms, resembling to those present in the dorsal surface of the osteoderms of the Glyptodontidae Doedicurinae; (c) the evident thickness of the osteoderms, as in Glyptodon Owen; (d) area of contact and articulation of adjacent osteoderms very denticulate, with deep osseous interdigitating projections, as in Glyptodon and Glyptotherium Osborn, but here more evident; (e) larger osteoderms of the dorsal carapace showing, in the dorsal surface, many little conical tubercles, having some resemblance to Panochthus tuberculatus Burmeister. The presence of this new species in the early late Pleistocene of the Mesopotamic region is another element that adds to the biogeographical characterization of this particular area, especially evident during the warm and humid pulses of the late Pleistocene. In turn, this species represents the most complete record of the genus outside the Pampean region and partially complete the stratigraphic and geographic distribution of the genus.