共查询到20条相似文献,搜索用时 0 毫秒
1.
Three Santacrucian borhyaenoids, Cladosictis patagonica, Pseudonotictis pusillus and Sipalocyon gracilis, are analyzed from a functional-adaptive perspective. Five extant placentals and one marsupial model are also examined in order to interpret the locomotor adaptations of these fossils. Pseudonotictis pusillus is the smallest of the Santacrucian borhyaenoids and is known from fragmentary remains; from its small size, dental specializations and elbow anatomy, this species was certainly not far ecologically from an extant weasel. The postcranium of Sipalocyon gracilis, although poorly known, suggests climbing capabilities, and the pseudo-opposable pollex indicates skilful manipulative behaviour. Cladosictis patagonica was an active predatory form, short-legged and able to climb, although it was a less specialized arboreal form than the contemporaneous Prothylacinus patagonicus; the proportions of its limbs recall that of a living South American marten, the tayra. The pseudo-opposable pollex of Cladosictis, as in Sipalocyon, indicates skilful manipulative behaviour. 相似文献
2.
C idade, G.M., S ouza-F ilho, J.P., H siou, A.S., B rochu, C.A., & R iff, D., 18 March 2019. New specimens of Mourasuchus (Alligatoroidea, Caimaninae) from the Miocene of Brazil and Bolivia and their taxonomic and anatomic implications. Alcheringa 43, 261–278. ISSN 0311-5518. Mourasuchus is one of the most peculiar crocodylians of all time, showing an unusual ‘duck-faced’ rostrum with thin, gracile mandibles. It includes four species restricted to the South American Miocene. Here, we describe ten late Miocene specimens of Mourasuchus, nine from the Solimões Formation of Brazil and one from Bolivia. All specimens are assigned to M. arendsi, but this assignment may change as the diversity and relationships within Mourasuchus are better understood. We also discuss several issues pertinent to the morphology of Mourasuchus: the presence of a braincase neomorph (the laterocaudal bridge), hypotheses about sexual dimorphism, the function of the squamosal ‘horns’ the presence of possible thermoregulatory functions in the genus. Additionally, the paleogeographic distribution of Mourasuchus in the Miocene of South America is also discussed. Giovanne M. Cidade* [giovannecidade@hotmail.com], Universidade de São Paulo Campus de Ribeirao Preto, Biologia, Avenida Bandeirantes 3900, Ribeirao Preto, 14040-900, Brazil; Jonas P. Souza-filho [jpdesouzafilho@hotmail.com], Universidade Federal do Acre, Departamento de Ciências da Natureza, Campus Universitário, UFAC, BR 364, Km 4, Distrito industrial, CEP 69915-900, Rio Branco, Acre, Brazil; Annie Schmaltz Hsiou [anniehsiou@ffclrp.usp.br], Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Departamento de Biologia, Avenida dos Bandeirantes, 3900, Ribeirão Preto, 14040-901, Brazil; Christopher A. Brochu [chris-brochu@uiowa.edu], University of Iowa, Iowa City, IA 52245, USA; Douglas Riff [driff2@gmail.com], Universidade Federal de Uberlandia, Uberlandia, 38400902, Brazil. 相似文献
5.
M ENZIES, J., D AVIES, H.L., D UNLAP, W.J. & G OLDING, S.D., June, 2008. A possible early age for a diprotodon (Marsupialia: Diprotodontidae) fossil from the Papua New Guinea highlands. Alcheringa 32, 129–147. ISSN 0311-5518. A fossil diprotodon jawbone coated and impregnated with a well-cemented fine breccia or tuff was recovered from weakly consolidated Pleistocene lacustrine sediments near Yonki in the Papua New Guinea highlands. The fine breccia includes angular rock and mineral fragments derived from country rock, accretionary lapilli and clay minerals. It does not include any identifiable primary volcanic material. The presence of accretionary lapilli and lack of volcanic clasts suggests an origin by phreatic eruption—an explosive eruption driven by the violent escape of gas. Minerals in the fine breccia have an age of 13.2 ± 0.2 Ma, middle Miocene, as indicated by 40Ar/ 39Ar analysis. This is the age of the country rock that was blasted by the phreatic eruption. Igneous activity in the Yonki area is thought to have ceased at 7.4 Ma (younger age limit of Elandora Porphyry; late Miocene), and so it is likely, but not certain, that the phreatic eruption occurred not later than 7.4 Ma. The jawbone, as far as can be told from its poor condition, is dentally similar to the late Pliocene and possibly Pleistocene ‘ Kolopsis’ watutense recovered from other sites in New Guinea. Probably, the jawbone, or the living marsupial, was buried in the fine breccia at the time of the phreatic eruption, and its remains were subsequently reworked by river erosion and redeposited in the lacustrine sediments. Recrystallization and loss of primary texture in some of the bone may be a result of heating at the time of, or preceding, the eruption. 相似文献
6.
C onran, J.G., B annister, J.M. & L ee, D.E., 2013. Fruits and leaves with cuticle of Laurelia otagoensis sp. nov. (Atherospermataceae) from the early Miocene of Otago (New Zealand). Alcheringa 37, 496–509. ISSN 0311-5518. Laurelia otagoensis sp. nov. Conran, Bannister & D.E. Lee (Laurales: Atherospermataceae) is described from the earliest Miocene Foulden Maar diatomite deposit, Otago, New Zealand. The new species is represented by mummified fossil leaves with well-preserved cuticle and associated clusters of achenes bearing persistent, long plumose styles. This basal angiosperm family is of significance because of its classic southern disjunctions and ecological importance in extant Gondwana-type rainforests, but has a very sparse fossil record. The present study describes one of very few convincing leaf fossils for Atherospermataceae and the only definitive fossil fruits. The presence of fossil Laurelia in Oligo–Miocene New Zealand combined with fossil leaf impressions from the late Eocene, Miocene dispersed cuticle and pollen from the Oligocene to Holocene shows that the family has had a long history in Cenozoic New Zealand. These new fossils also support palaeoclimatic data suggesting warmer conditions in the earliest Miocene of New Zealand. John G. Conran [john.conran@adelaide.edu.au], Australian Centre for Evolutionary Biology & Biodiversity and Sprigg Geobiology Centre, School of Earth and Environmental Sciences, Benham Bldg DX 650 312, The University of Adelaide, SA 5005 Australia; Jennifer M. Bannister [jennifer.bannister@xtra.co.nz], Department of Botany, University of Otago, PO Box 56, Dunedin, New Zealand; Daphne E. Lee [daphne.lee@otago.ac.nz], Department of Geology, University of Otago, PO Box 56, Dunedin, New Zealand. Received 17.12.2012; revised 9.4.2013; accepted 15.4.2013. 相似文献
7.
Pseudaptenodytes macraei is redescribed in detail using current avian anatomical terminology. The age of the species is constrained to the late Miocene, and two humeral autapomorphies are identified for the species: a flattened elliptical ventral portion of the fossa tricipitalis and a curved margo cranialis lacking a preaxial angle. Pseudaptenodytes macraei is a distinct taxon based on a diagnostic-type specimen, but it is recommended that the nominal congener Pseudaptenodytes minor be designated a nomen dubium pending the discovery of more complete material. 相似文献
8.
Park, T. & Fitzgerald, E.M.G. September 2012. A late Miocene–early Pliocene Mihirung bird (Aves: Dromornithidae) from Victoria, southeast Australia. Alcheringa 36, 427–430. ISSN 0311-5518. An incomplete tarsometatarsus identified as an indeterminate species of Dromornithidae is described from the upper Miocene–lower Pliocene shallow marine Black Rock Sandstone at Beaumaris, Victoria, Australia. This isolated specimen represents one of the few pre-Pleistocene dromornithids with a well-constrained geologic age. Additionally, it is one of the few pre-Quaternary dromornithid fossils recorded from southeast Australia. Comparisons with known dromornithid taxa suggest that the Beaumaris dromornithid is distinct from previously established species. This hitherto unknown species of dromornithid in the late Neogene of southeastern Australia cautions against deriving evolutionary patterns solely on the basis of fossils from northern Australia. 相似文献
9.
The first lungfish tooth plate from the Las Flores Formation, Chubut, southern Argentina, is described. This is the youngest ceratodontid known from the continent. In Africa, ceratodonts disappeared in the Eocene. Afterwards, they are only known from Australia until their extinction during the Pleistocene. The Las Flores tooth plate also represents the southernmost lungfish known since the Coniacian (early Late Cretaceous). 相似文献
10.
In South America, various state organizations have an investment in producing some kind of ‘national’ cinema. Although different countries around the world have varied levels of government involvement, the four countries I would like to examine – Argentina, Bolivia, Chile and Peru – can be drawn upon for their similarities and the shared regional context in which their policies operate. Particularly important is the fact that an increase in government involvement and support has been taking place in the twenty‐first century against predictions that enhanced global capital would weaken the function of the state. Furthermore, it is frequently the case that policy, in the form of government regulation and funding, provides the only means for cinema’s continued existence, visibility and access to the public and thus cannot be underestimated. Complicating these factors is the fact that while legislation is in place, government bodies often struggle to implement the policies in a practical manner. This article examines these issues and suggests the effect they are having on the cinematic culture of the region. 相似文献
12.
AbstractWe report the first record of the genus Xiphactinus from southern South America. The recovered fossil material consists of an associated maxilla and abdominal vertebra, probably derived from latest Maastrichtian marine deposits of the Salamanca Formation in Chubut Province, Argentina. Xiphactinus has been widely reported from Late Cretaceous strata throughout the Northern Hemisphere, although to date, equivalent Southern Hemisphere occurrences include only a single specimen from Venezuela. Our new discovery thus indicates that Xiphactinus had a much more cosmopolitan distribution, encompassing the southern paleolatitudinal extremities of South America during the terminal Cretaceous. Julieta J. De Pasqua [julietadepasqua@gmail.com], Laboratorio de Anatomía Comparada y Evolución de los Vertebrados, Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’, Av. Ángel Gallardo, 470, C1405DJR, Buenos Aires, Argentina; Federico L. Agnolin [fedeagnolin@yahoo.com.ar], Laboratorio de Anatomía Comparada y Evolución de los Vertebrados, Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’, Av. Ángel Gallardo, 470, C1405DJR, Buenos Aires, Argentina. CONICET; Fundación de Historia Natural ‘Félix de Azara’, Departamento de Ciencias Naturales y Antropología, Universidad Maimónides; Hidalgo 775 piso 7, C1405BDB, Buenos Aires, Argentina; Sergio Bogan [sergiobogan@yahoo.com.ar], Fundación de Historia Natural ‘Félix de Azara’, Departamento de Ciencias Naturales y Antropología, Universidad Maimónides; Hidalgo 775 piso 7, C1405BDB, Buenos Aires, Argentina. 相似文献
13.
L ee, M., E lias, R.J., C hoh, S.-J. & L ee, D.-J., May 2018. Palaeobiological features of the coralomorph Amsassia from the Late Ordovician of South China. Alcheringa XXX, X–X. ISSN 0311-5518. Amsassia yushanensis sp. nov. occurs in the Late Ordovician Xiazhen Formation at Zhuzhai, Jiangxi Province of southeastern China. This species is characterized by typical phacelocerioid organization of modules comparable with the other Amsassia species described in recent literature. Bipartite fission, in which a parent module divided into two parts, is by far the most common type of increase in this species; tripartite and quadripartite types of axial fission do occur but are relatively uncommon. Processes of module division are similar to those of A. shaanxiensis and A. koreanensis, and also occurred in tetradiids. In A. yushanensis, restoration of coralla was occasionally accompanied by recovery of a damaged or injured module or group of modules probably following an influx of sediment, as observed in some favositoid corals. Amsassia superficially resembles Lichenaria, a representative genus of the most primitive stock of tabulate corals of Ordovician age, and has likely been mistakenly identified as Lichenaria in the North China Platform. Available information suggests that the validity of a reported occurrence of Lichenaria in the South China Platform is also questionable. Mirinae Lee [mirinae.lee@kopri.re.kr] Division of Polar Earth-System Sciences, Korea Polar Research Institute, 21990, Incheon, Republic of Korea; Robert J. Elias [Robert.Elias@umanitoba.ca] Department of Geological Sciences, University of Manitoba, Winnipeg, R3T 2N2, Canada; Suk-Joo Choh [sjchoh@korea.ac.kr] Department of Earth and Environmental Sciences, Korea University, Seoul, 02841, Republic of Korea; Dong-Jin Lee [djlee@anu.ac.kr] Department of Earth and Environmental Sciences, Andong National University, Andong, 36749, Republic of Korea and College of Earth Sciences, Jilin University, Changchun 130061, PR China. 相似文献
15.
The time of appearance of a persistent and demographically-viable hunter-gatherer population in late Pleistocene southern South America must be determined by evaluating evidence from as large as possible a sample of candidate archaeological sites in the region. We co-ordinated the AMS dating of multiple bone and charcoal samples from previously-excavated strata at the following sites: Arroyo Seco 2, Paso Otero 5, Piedra Museo, and Cueva Tres Tetas (all in Argentina), and Cueva del Lago Sofia 1 and Tres Arroyos (both in Chile). With one possible exception, we did not obtain new results to confirm earlier observations of pre-Clovis-age cultural activity at any of the sites considered in this study. The possible exception, Arroyo Seco 2, is considered in detail elsewhere [Politis G., Gutierrez M.A., Scabuzzo, C. (Eds), in press. Estado actual de las Investigaciones en el sitio 2 de Arroyo Seco (región pampeana, Argentina). Serie Monográfica INCUAPA 5. Olavarría]. However, our results for the samples which were the most preferred indicators of cultural events (hearth charcoal and cut-marked bone) confirm that people were in the southern cone of South America at or soon after 11,000 BP (13,000 cal BP). Considered alongside recent age estimates for the Clovis culture in North America, these results imply the contemporaneous emergence of a consistent and archaeologically-robust human occupation signal at widely-separated locations across the Western Hemisphere. Such findings suggest that Palaeoindian demic expansion may have involved more than one terminal Pleistocene dispersal episode. 相似文献
16.
The multiple and varied trajectories of chiefdom development in northern South America (and adjacent Central America) offer a rich opportunity for evaluating generalizations about the processes of chiefdom development. Sequences of the south coast of Ecuador, the Alto Magdalena, Calima, the Muisca region, Barinas, and the Tairona region are well enough documented to attempt to use in this way. Although centralized hierarchical societies develop in all these regions, there are many differences in the character of centralization and hierarchy and in the pacing of the development, and none of the traditionally proposed forces of social change is entirely adequate to account for these cases. Attention to the role played by competition between aspiring chiefs and their factions offers promise for more satisfactory generalizations that could be evaluated through further comparative study. 相似文献
17.
Archaeology is a practice that exists within various social contexts. As such, the way it is practiced is dependent upon the class interests of those who fund and undertake archaeological investigations. These interests in turn can be influenced by existing political regimes. In this article, I discuss how class interests have influenced the direction of Brazilian archaeology for the past century and a half. 相似文献
18.
S adler, T., K roh, A. &; G allagher, S.J., March 2016. A review of the taxonomy and systematics of the echinoid genus Monostychia Laube, 1869 Laube, G.C., 1869. Über einige fossile Echiniden von den Murray Cliffs in Süd-Australien. Sitzungsberichte der Kaiserlichen Akademie der Wissenschaften zu Wien, mathematisch-naturwissenschaftliche Classe. Abtheilung I 59, 183–198. [Google Scholar]. Alcheringa 40, xxx–xxx. ISSN 0311-5518A review of Monostychia, a stratigraphically important clypeasteroid echinoid genus in southern Australian Oligocene/Miocene strata, reveals uncertainty in relation to morphological features used in taxonomy. The result is that the exact systematic position of the genus remains unresolved at subfamily level. Monostychia and its type species, M. australis, are redescribed. Monostychia australis is restricted to the lower to middle Miocene Glenforslan Formation of the Murray Basin. Three other species currently within Monostychia, M. etheridgei, M. loveni and M. elongata, are discussed. Although it is concluded that M. etheridgei belongs in the genus and is a distinct species, the taxonomic position of M. loveni is questioned, and the validity of M. elongata as a separate species from M. australis remains uncertain. This work lays the foundation for further revisions of Monostychia with an expectation that such work will provide the basis for character determination that may be useful across other echinoid taxa. Tony Sadler [t.sadler@uq.edu.au] and Stephen J. Gallagher [sjgall@unimelb.edu.au], School of Earth Sciences, University of Melbourne, Victoria 3010, Australia; Andreas Kroh [andreas.kroh@nhm-wien.ac.at], Natural History Museum Vienna, Department of Geology and Palaeontology, Burging 7, 1010, Vienna, Austria. 相似文献
19.
Orinoquia is one of the most important riverine ecosystems complexes of the world. However, it has been seldom recognized as an ecological or historical entity in general accounts of South American archaeology. This essay reviews systematically and comparatively the archaeology of Orinoquia, by discussing research done from the 1940s onwards in all the areas of the Orinoco Basin: the Andes, the plains or llanos, the Orinoco river proper, the highlands of Guayana, and the Delta. It is proposed that, in the last 20 years, there has been a sustained movement away from a traditional archaeology, concerned mostly with environmental determinism and cultural history, to new and pluralistic models that share, in spite of their diversity, a regional, long-term, and multidisciplinary approach. 相似文献
20.
Here we report the first example of associated short-faced bear fossils from South America. The specimens represent three individuals referable to the Ensenadan (early to middle Pleistocene) species Arctotherium angustidens (Ursidae, Tremarctinae), the giant South American short-faced bear. Although the fossil record of short-faced bears in South America is very rich, they have not previously been recorded in association. These three individuals were found in a cave during quarry exploitation. We suggest that these bears represent the first record of a family group and open the discussion about cave utilization and hibernation or torpor by South American short-faced bears. 相似文献
|