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Contributions to the knowledge of Antarctodon sobrali(Mammalia:Astrapotheria)from the Eocene of Antarctica

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Advances in Polar Science 2024年第1期35卷 48-62页

作者： Javier N.GELFO Consejo Nacional de Investigaciones Científicasy Técnicas(CONICET) Buenos Aires C1425FQBArgentina División Paleontología Vertebrados Museo de La PlataFacultad de Ciencias Naturales y Museo de La PlataUniversidad Nacional de La PlataLa Plata B1900FWAArgentina

The Astrapotheria constitutes one of the five orders of extinct South American native ungulates,with a fossil record that also extends to the Eocene of the Antarctic *** contrast to the abundant specimens known for litoptern Sparnotheriodontidae and metatherians,astrapotheres are represented by scant remains assigned to the endemic Antarctodon sobrali and indeterminate astrapotheres,restricted to levels 35C_(u0)and 35n of the Cucullaea I Allomember of the la Meseta *** discovery of alower molar assignable to this species in the Eocene levels of Seymour(Marambio)Island,enables a revision of the diagnosis and the homologies of the dental characters used to describe this taxon.A reanalysis of its phylogenetic relationships reveals the nearly simultaneous presence of basal astrapotheres in the early Eocene of Itaboraí(Brazil),Patagonia,and West *** taxa are characterized by lacking dental specializations usually associated with more abrasive diets like terminal forms of Uruguaytheriinae and *** appears to have thrived on the Antarctic continent during the Early Eocene Climatic Optimum within the paleoclimatic context of a hot-house *** present conditions in Antarctica where no terrestrial mammals inhabit,the early Eocene climate was characterized by warmer temperatures and a biologically diverse environment rich in primary producers,dominated by Nothofagus forests,encompassing both deciduous and evergreen forests,which supported a diverse assemblage of continental vertebrates.

关键词： Astrapotheria Antarctodon Eocene Seymour Island la Meseta Formation

Review of the Cretaceous avian diversity of Antarctica:a changing scenario for the evolution of early Neornithine birds

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Advances in Polar Science 2024年第1期35卷 1-13页

作者： Carolina ACOSTA HOSPITALECHE Facundo IRAZOQUI Paula BONA Ariana PAULINA-CARABAJAL División Paleontología de Vertebrados Museo de La PlataFacultad de Ciencias Naturales y MuseoUniversidad Nacional de La PlataPaseo del Bosque s/nLa Plata B1900FWAArgentina Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET) Buenos Aires C1425FQBArgentina División Paleontología Vertebrados Museo de La Plata-Anexo ⅡFacultad de Ciencias Naturales y MuseoUniversidad Nacional de La PlataCalles 122 y 60La Plata B1900FWAArgentina Instituto de Investigaciones en Biodiversidad y Medioambiente(INIBIOMA) Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad Nacional del ComahueSan Carlos de Bariloche R8400GAMArgentina

The worldwide record of Cretaceous Neornithes and Neornithine-like birds is both controversial and poorly ***,in recent years,the Antarctic continent has yielded a substantial number of Maastrichtian avian specimens,contributing significantly to our understanding of the early evolution of this ***,the keen interest and collaborative efforts of various paleornithologists have resulted in a wealth of knowledge,which we have thoroughly reviewed,updated,and discussed in the context of recent discoveries.

关键词： Maastrichtian Antarctic Peninsula Vega Island Seymour(Marambio)Island Neornithes birds

The first record of dermochelyid turtles in the Eocene of Tierra del Fuego:new insights on the evolution of the Weddellian faunas

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Advances in Polar Science 2024年第1期35卷 63-77页

作者： Paula BONA Juliana STERLI Marcelo Saúl de la FUENTE Eduardo OLIVERO Marta S.FERNÁNdeZ Marcelo REGUERO División Paleontología Vertebrados Museo de La Plata-Anexo IIFacultad de Ciencias Naturales y MuseoUniversidad Nacional de La PlataLa Plata B1900FWAArgentina Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET) Ciudad Autónoma de Buenos Aires C1425FQBArgentina museo Paleontológico Egidio Feruglio Trelew U9100Argentina Instituto de Evolución Ecología Histórica y Ambiente-CONICETSan Rafael CP5600Argentina Centro Austral de Investigaciones Científicas-CONICET Universidad Nacional de Tierra del FuegoUshuaia CP 9410Argentina División Paleontología Vertebrados Museo de La PlataUniversidad Nacional de La PlataLa Plata B1900FWAArgentina

The Antarctic Paleogene marine fossil record has been the key to reconstructing the evolution of the Weddellian Sea and final dismemberment of Southern *** this context,Eocene marine vertebrates from Seymour(Marambio)Island have provided valuable *** present the first Eocene record of marine reptiles from the southern Atlantic Coast of South *** corresponds to several postcranial turtle remains represented by a proximal end of the right humerus,three caudal and one thoracic vertebrae,a fragment of the left pubis,and ten ossicles of the dorsal carapace,coming from the Leticia Formation(late-mid Eocene)at Cabo Tiburones,Tierra del Fuego,*** materials show severalfeatures such as the size and general morphology of the humerus and vertebrae,and the presence of relatively small,irregular,smooth,and unkeeled ossicles,which allow us to assign them to dermochelyidae *** are a cosmopolitan group ofcryptodiran turtles,registered from the late Cretaceous up to the recent,with some physiological-biological peculiarities(e.g.,endothermy and an exclusive jellyfish-based diet)and characterized by the presence of an osseous carapace formed by *** new finding from the Leticia Formation is an addition to the scarce and extremely fragmentary record of Eocene dermochelyids from the southern seas like those from the la Meseta and Submeseta formations(Antarctica)and the Waihao and Burnside formations(New Zealand).This new information allows us to discuss the presence of these turtles in such high latitudes in the past and its implication in the evolution of the Weddellian fauna.

关键词： marine reptiles sea turtles dermochelyidae Paleogene la Meseta Formation Submeseta Formation Leticia Formation

Long-term trends in the abundance and breeding performance in Adélie penguins:the Argentine Ecosystem Monitoring Program

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Advances in Polar Science 2024年第1期35卷 132-140页

作者： Mariana A.JUÁRES AnahíM.SILVESTRO Brenda C.ALFONSO M.Mercedes SANTOS departamento Biología de Predadores Tope Instituto Antártico Argentino(IAA)Buenos Aires B1650CSPArgentina Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET) Buenos Aires C1425FQBArgentina laboratorios Anexos Facultad de Ciencias Naturales y MuseoUniversidad Nacional de La PlataLa Plata B1904AMAArgentina INEdeS(CONICET-UNLu) Buenos Aires C1425FQBArgentina Facultad de Ciencias Naturales y museo Universidad Nacional de La PlataLa Plata B1900FWAArgentina Instituto Antártico Argentino(IAA) Buenos Aires B1650CSPArgentina

In this work,we report long-term trends in the abundance and breeding performance of Adélie penguins(Pygoscelis adeliae)nesting in three Antarctic colonies(i.e.,at Martin Point,South Orkneys Islands;Stranger Point/Cabo Funes,South Shetland Islands;and Esperanza/Hope Bay in the Antarctic Peninsula)from 1995/96 to 2022/*** yearly count data of breeding groups selected,we observed a decline in the number of breeding pairs and chicks in crèche at all colonies ***,the magnitude of change was higher at Stranger Point than that in the remaining ***,the index of breeding success,which was calculated as the ratio of chicks in crèche to breeding pairs,exhibited no apparent trend throughout the study ***,it displayed greater variability at Martin Point compared to the other two colonies under *** the number of chicks in crèche of Adélie penguins showed a declining pattern,the average breeding performance was similar to that reported in gentoo penguin colonies,specifically,those undergoing a population increase(even in sympatric colonies facing similar local conditions).Consequently,it is plausible to assume a reduction of the over-winter survival as a likely cause of the declining trend observed,at least in the Stranger Point and Esperanza ***,we cannot rule out local effects during the breeding season affecting the Adélie population of Martin Point.

关键词： long-term monitoring Adélie penguin breeding pairs chicks crèched breeding success population trends

Exploring the size of Andean condor foraging groups along an altitudinal and latitudinal gradient in the Tropical Andes: Ecological and conservation implications

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Current Zoology 2024年第2期70卷 225-232页

作者： Diego Mendez Felix Hernan Vargas JoséHernan Sarasola Pedro P.Oleaa departamento de Ecologia Universidad Autonoma de MadridCalle Darwin 228049MadridSpain museo Nacional de Historia Natural Calle 26 s/nCota CotaLa PazBolivia The Peregrine Fund 5668 West Flying Hawk LaneBoiseID 83709USA Centro para el Estudio y Conservacion de Aves Rapaces en Argentina(CECARA) Universidad Nacional de La PampaAvda Uruguay 1516300 Santa RosaLa PampaArgentina Instituto de las Ciencias Ambientales y de la Tierra de la Pampa(INCITAP-CONICET) Avda.Uruguay 1516300 Santa RosaLa PampaArgentina Centro de Investigacion en Biodiversidad y Cambio Global(CIBC-UAM) Universidad Autonoma de MadridMadridCalle Darwin 228049Madrid Snain

Patterns of variation in the size of vulture foraging groups,and their ecological causes and consequences,remain litle explored despite strong links with the carrion recycling service that this key functional group *** documented the group size-frequency pattern of Andean con-dors Vultur gryphus gathered to feed on 42 equine carcasses experimentally placed in Bolivia,between 2012 and 2019,along an elevation range of 1,300-4,500 m *** on the location(altitude and latitude)of the foraging groups,we examined the relationship between their size and species'population parameters(size and trend),habitat conditions,and livestock carcass availability and *** utilized a high frequency(93%)of carcasses forming groups that ranged from 1 to 80 individuals(mean=25,median=18)and shaped a"lazy-J curve"typical pattern of size-frequency distribution whereby few groups(5,12%)were large(>55 individuals)and most(21,50%)were relatively small(lated to altitude in that most larger groups formed at lower sites(below c.3,000 m asl),likely following an altitudinal gradient whereby larger groups are more likely to form around larger carcasses(i.e.,cattle),which are more likely to occur at lower *** of population size,group size could be an adaptive response of condors via local enhancement for improving individual scavenging *** information gaps on this topic still exist,thus we provide a set of questions to address them,especially amidst the unrestricted impacts of human activities that condition vulture survival globally.

关键词： condor andino fusion-fission dynamics group size scavenger social foraging vultures.

Highly divergent sympatric lineages of Leptotila verreauxi(Aves:Columbidae)suggest a secondary contact area in the Isthmus of Tehuantepec,Mexico

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Avian Research 2024年第1期15卷 12-21页

作者： Orlando J.Espinosa-Chávez Adolfo G.Navarro-Sigüenza Hernando Rodríguez-Correa Luis A.Sánchez-González museo de Zoología“Alfonso L.Herrera” Depto.de Biología EvolutivaFacultad de CienciasUniversidad Nacional Autonoma de MexicoApdo.Postal 70-399CP 04510Ciudad de MexicoMexico Posgrado en Ciencias Biologicas Unidad de PosgradoEdificio D1◦PisoCircuito de PosgradosCiudad UniversitariaUniversidad Nacional Autonoma de MexicoCoyoacanCP 04510CDMXMexico Escuela Nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autonoma de Mexico.Antigua Carretera a Patzcuaro No.8701 Col.Ex Hacienda de San Jose de la HuertaC.P.58190MoreliaMichoacanMexico

Due to a complex geological and biotic history,the Isthmus of Tehuantepec(IT),has been long recognized as a driver for the evolutionary divergence of numerous lowland and highland *** distributed in the lowlands of the American continent,the White-Tipped Dove(Leptotila verreauxi)is a polytypic species with 13 recognized *** of these have been recorded in Mexico,and the distribution of three abuts at the IT,suggesting a contact *** estimate phylogenetic patterns,divergence times and genetic differentiation,we examined two mt DNA(ND2 and COI)and one n DNA(β-fibint 7)*** also used correlative ecological niche models(ENM)to assess whether ecological differences across the IT may have acted as a biogeographical *** estimated paleodistributions during the Middle Holocene,last Glacial Maximum and last Interglacial,to evaluate the influence of climate changes on the distribution and demographic *** results showed genetically distinct lineages that diverged approximately 2.5 million years *** and ecological factors may have played a dual role in promoting differentiation,but also in the formation of a secondary contact zone in the southern *** ecological niche comparisons indicated that the ecological niche of sympatric lineages at the IT are not identical,suggesting niches divergence;in addition,environmental niche models across the region indicated no abrupt biogeographic barriers,but the presence of regions with low *** results suggest that genetic differentiation originated by a vicariant event probably related to environmental factors,favored the evolution of different ecological ***,the absence of a biogeographic barrier but the presence of less suitable areas in the contact regions,suggest that secondary contact zones may be also maintained by climatic factors for the eastern group,but also by biotic interactions for the western group.

关键词： Biogeographical boundary Humid and dry forests Isthmus of Tehuantepec Phylogeography Secondary contact

Phylogenetic framework for coevolutionary studies： a compass for exploring jungles of tangled trees

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Current Zoology 2016年第4期62卷 393-403页

作者： Andres MARTiNEZ-AQUINO Division Zoologfa Invertebrados Museo de La Plata FCNyM UNLP Paseo del Bosque s/n 1900 La Plata Argentina

Phylogenetics is used to detect past evolutionary events, from how species originated to how their ecological interactions with other species arose, which can mirror cophylogenetic patterns. Cophylogenetic reconstructions uncover past ecological relationships between taxa through inferred coevolutionary events on trees, for example, codivergence, duplication, host-switching, and loss. These events can be detected by cophylogenetic analyses based on nodes and the length and branching pattern of the phylogenetic trees of symbiotic associations, for example, host-parasite. In the past 2 decades, algorithms have been developed for cophylogetenic analyses and implemented in different software, for ex ample, statistical congruence index and event-based methods. Based on the combination of these approaches, it is possible to integrate temporal information into cophylogenetical inference, such as es- timates of lineage divergence times between 2 taxa, for example, hosts and parasites. Additionally, the advances in phylogenetic biogeography applying methods based on parametric process models and combined Bayesian approaches, can be useful for interpreting coevolutionary histories in a scenario of biogeographical area connectivity through time. This article briefly reviews the basics of parasitology and provides an overview of software packages in cophylogenetic methods. Thus, the objective here is to present a phylogenetic framework for coevolutionary studies, with special emphasis on groups of parasitic organisms. Researchers wishing to undertake phylogeny-based coevolutionary studies can use this review as a ＂compass＂ when ＂walking＂ through jungles of tangled phylogenetic trees.

关键词： coevolution cophylogenetic analyses host-parasite molecular systematics parametric biogeography symbiosis.

The marine Jurassic of Argentina： a biostratigraphic framework

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Episodes 2008年第3期31卷 326-335页

作者： Alberto C. Riccardi Facultad de Cieneias Naturales y museo Universidad Nacional de La Plata Paseo del Bosque s/n 1900 La Plata Argentina

In Argentina the best and most complete marine Juras- sic succession is exposed between 32° and 39° S, along a N-S belt roughly coincident with the border with Chile. Here all stages, except the Kimmeridgian, are represented by marine facies. Ammonites have provided a biostratigraphic framework to date and correlate lithostratigraphic units and sequences, to reconstruct the history of the marine fill, and allow the development of other palaeontological and geological studies. Recent studies on the systematics and/or biostratigra- phy of Andean ammonites have provided the basis for the presentation of a summary of the 45 ammonite zones of the Jurassic of west-central Argentina and to stress its significance in reconstructing the palaeogeographic evolution of that region.

关键词：侏罗纪海洋阿根廷生物地层学

Quantifying the relative importance of direct and indirect effects influencing bird nestling growth

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Integrative Zoology 2022年第3期17卷 408-419页

作者： Luciano N.SEGURA Facundo X.PAlaCIO División Zoología Vertebrados Facultad de Ciencias Naturales y MuseoUniversidad Nacional de La PlataBuenos AiresArgentina

Nestling growth parameters are integral components of avian life-history strategies as they are crucial determinants of individual *** many factors impact on nestling growth,the relative contribution of each one is still debated in the *** studies rely on the assumption that each factor directly affects nestling growth,but indirect effects mediated by other factors are usually the rule in *** this study,we present a comprehensive view of both direct and indirect factors affecting nestling growth using the Red-crested Cardinal(Paroaria coronata)as model *** evaluated the relative importance of different habitat(forest structure),biotic interactions(botfly larvae ectoparasitism,number of siblings,hatching order),and temporal factors(time of breeding)on nestling growth parameters in 278 nestlings of 128 nests by using piecewise structural equation *** found that botfly ectoparasitism had the strongest direct effect on nestling growth and,in turn,forest structure increased the probability of botfly ***,the interaction between the number of siblings and hatching order influenced nestling growth,indicating that the first and second nestlings had disproportionately higher growth rates in large than in small *** of breeding also showed a strong positive indirect effect on botfly occurrence,as well as a weak direct positive effect on nestling *** results demonstrate that,under natural conditions,nestling growth is driven by different factors acting not only directly,but also indirectly on this essential life history trait,and that these factors weave a complex web of interrelated variables.

关键词： biotic interactions forest structure Red-crested Cardinal structural equation models time of breeding