4 jan. Paleontologia de vertebrados da transição entre os grupos Tubarão e Passa Dois (neopaleozóico) no centro-leste do Estado de São Paulo. Vertebrados Faunas Y Fologenia Aplicacion Y Sociedad by alcocweibarcurl.cf Study Group. Discover them in site, zip, pdf, ppt, rar, txt, as well as word. read on-line Paleontologia De Vertebrados Faunas Y Fologenia Aplicacion Y Sociedad in our website. Obtain guide in pdf, word, txt, ppt, zip, site, as well as .
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Sphenodon is the only survivor of a group that was diverse during the late Triassic and. Jurassic times to diminish toward the Early Cretaceous. The group was. Área de concentração: Paleontologia e Estratigrafia Orientador(es): Lílian Modelo tafonômico para vertebrados de depósitos de tanque do Nordeste do Brasil. PRACTICA Nº1 INTRODUCCION A LA PALEONTOLOGIA DE VERTEBRADOS. Dania Ucumari button above. READ PAPER. Download pdf. ×Close.
Dating and regional significance. The ages reported by Fastovsky et al. Gradstein et al. On the other hand, Rubio-Cisneros and Lawton convincingly argued for slightly younger ages Salvador, La Boca local fauna is the earliest terrestrial vertebrate assemblage from Mexico, it includes mammal-like reptiles, early dinosaurs, pterosaurs, early diapsids, sphenodonts and early mammals Clark et al.
The U-Pb dating results constrain the age to the late Middle Jurassic, thus refining the biochronologic assessment. This site is well known long ago cf.
Kilmer, ; Gastil et al. Renne et al. Late Cenozoic-Quaternary alluvial deposits unconformably rest on this cover. The 40ArAr ages obtained from the tuff sheets have a small spread On the other hand, Busby in her regional tectonic study, convincingly argues for regarding El Rosario as a forearc basin itself, and so names it Busby, , fig.
El Rosario l. Lillegraven, , ; Morris, , a , b , ; Molnar, includes hadrosaurian and theropod dinosaurs as well as mammals non-therian and therian , it resembles Judithian faunas of western North America e. This site is located in the Guanajuato Mining District, which holds the world class silver deposits of Guanajuato and, is geologically known long ago cf.
The Guanajuato Conglomerate is non-conformably overlain by a thick volcanic succession that includes upward these units: Losero Fm. A lower member lava flow yielded a 40KAr age of Previously though, Fries et al.
The geologic importance of this fact needs no further stressing. The Marfil l. The condy- larth Hyopsodus and perissidactyl Helaletes are characteristic Early Bridgerian taxa cf. Robinson et al. The lava flow age further corroborates this assignment.
Finally, the fauna shows an overall North American biogeographic affinity, but endemism is apparent; some of the rodents e. Marfilomys show vague affinities with the early caviomorphs of South America cf.
Patterson and Wood, Detailed geologic information for this place is lacking. The Cenozoic sequence includes these units from the bottom up :? Eocene, fluvio-lacustrine, fine-grained facies prevail; it is sparsely fossiliferous , Llano de Lobos Tuff Oligocene, a thick pyroclastic sheet , Yucudaac Andesite Oligocene, a thick flow stack , San Marcos Andesite Oligocene, a less thick lava flow stack , and Chilapa Fm.
Oligocene, intertongues the latter further north, it is largely lacustrine with abundant silicified limestone. On the other hand, Martiny et al. Later, Cerca et al. Whichever the case, such ages help to date the onset of the taphrogenic event subse-quent to the laramidic deformation in western Oaxaca, whereby the Cretaceous units became folded, faulted and uplifted, and horst and graben structurs developed.
Chadronian , which is corroborated by the isotopic ages discussed above. It is located in one of the basins that bear Tertiary fluvio-lacustrine sequences associated to volcanic emplacements. Unit 1. Unit 2. Unit 3.
H2O , gypsum, siltstone and fine grained sandstone strata lake facies.
The upper part largely consists of fresh water limestone. Unit 4. Unit 5. Unit 6. The Baucarit Fm. Finally, Quaternary alluvium deposits unconformably rest on this sequence.
The palagonitized basalt flow yielded a 40KAr age of Given that palagonitized basalts are not well suited for K-Ar dat- ing, this age is questionable. Geologically, these isotopic and biochronologic ages date the beginning of basin develop- ment in northwestern Sonora.
The Cenozoic includes andesitic lava flows at the base, and the Suchilquitongo Fm. The vertebrate fossils Suchilquitongo l. The Suchilquitongo Fm. Quaternary deposits and soils unconformably overlie the previous units. The Etla Ignimbrite member yielded 40KAr ages of The Suchilquitongo l. Harrison, Marsland and Sheep Creek; cf. Tedford et al. This assignment is consistent with the presented isotopic ages. Finally, the Suchilquitongo l. Quaternary deposits and soil crown the Cenozoic sequence.
Google Scholar Karsten, H. Google Scholar Lydekker, R. Contribution to the knowledge of the fossil vertebrates of Argentina. The extinct edentates of Argentina. Google Scholar Marshall, L.
Mammals and stratigraphy: geochronology of the Continental mammal-bearing Quaternary of South America. The Eocene Pleistocene vertebrates of Bolivia and their stratigraphic context: a review.
I Vertebrados 3—4 : — Google Scholar Morgan, G. Miocene and Pliocene vertebrates from Arizona. Google Scholar Ochsenius, C. Google Scholar Oliveira, E. Quaternary vertebrates and climates of southern Brazil. Google Scholar Oppenheim, V.
The fossiliferous basin of Tarija, Bolivia.
Google Scholar Osborn, H. Glyptotherium texanum, a new glyptodont, from the lower Pleistocene of Texas. Google Scholar Pascual, R.
Sociedade de Paleontologia de Vertebrados
Evolving climates and mammal faunas in Cenozoic South America. Land mammals: paradigm for Cenozoic American geobiotic evolution.
Conveners Late Cenozoic mammals: dispersal between Americas. Google Scholar Paula Couto, C. Tratado de Paleomastozoologia. Estudio morfofuncional del aparato hiodeo deGlyptodon cf. Google Scholar Pujos, F. A systematic reassessment and paleogeographic review of fossil Xenarthra from Peru. Google Scholar Rabassa, J. Chronology of the Late Cenozoic Patagonian glaciations and their correlation with biostratigraphic units of the Pampean region Argentina.
Megafauna do Pleistoceno. Google Scholar Rinderknecht, A. Estudios sobre la familia GlyptodontidaeGray, Google Scholar Rouse, I. Palaeobiogeography of the late Pleistocene pampatheres of South America. Paula-Couto, ; Bergqvist et al. Several other features e. Cruz, ; Zurita et al. Panochthus are believed to have been more ecologically tolerant Zurita et al. Therefore, assuming the validity of those autoecologic inferences, the absence of these large cingulates may be related to a more humid envi- ronment in the LPGS area during the accumulation of its thanatocoenosis.
Sitio Paleontológico Sanga da Alemoa
The overrepresentation of teeth and vertebrae is expected for fossil concentrations for two main reasons: The high quantity of astragalus and calcaneus observed, espe- cially for E. If the sorting resulting from transport had been the factor responsible for the overrepresentation of calcaneus and astragalus very transportable skeletal elements according to FTI groups an overrepresentation of other very transportable elements would be expected, such as phalanges and metapodials commonly found in other Cenozoic deposits of Brazil; e.
Excepting the transport, it is Fig. Graphic representation with results of taphonomic analysis on LGPS vertebrate reasonable that the abundance of individuals of E. However, the low amount of phalanges and metapodials still LGPS had undergone a much less destructive taphonomic history remains intriguing.
It is likely that these skeletal elements may than other analogous deposits, rendering the absence of osteo- have been removed from the thanatocoenosis due to more selective derms in LGPS even more intriguing. Biogenic removal of the occurrence of few desiccation marks. The presence of a moist phalanges and metapodials due to scavenging is excluded because: Wear marks on long and short bones of E.
Right astragalus, MN V; B. Distal end of left tibia, MN V; C. Left calcaneus, MN V; D. A irregular breaks; B smooth breaks; and C columnar breaks.
Irregular and perpendicular to long axis and columnar breaks are both likely produced prior to fossilization, when skeletal elements still retains some original plasticity Shipman et al. On the other hand, smooth breaks, perpendicular to long axes, are produced after the fossilization, when bones have already undergone some minerali- zation process Shipman et al.
Such post-fossilization breaks are generally caused by loading due to increased sedimentary supply Shipman, ; Lyman, This suggests that the taphonomic history for LGPS accumulation was different from those inferred for other tanks e.
Abrasion due to reworking was has been inferred for assem- blages of tanks e. However, this is improbable for LGPS, otherwise the specimens would be more fragmented than the observed. For this reason, the wear marks are likely due to abrasion during transport. Thus, considering the grades of abrasion and the analysis of trans- portation, it is likely that LGPS thanatocoenosis experienced a Fig.
Otherwise, a small amount of less transportable elements e. This pattern, coupled with contrasting with other known tanks of northeastern Brazil e. However, the this hypothesis Behrensmeyer, It may be simply due to the type of sedi- extremely arid climate see Ribeiro, Pyritization was not ments that were available in the source-area.
Moreover, it seems observed on the surface of the specimens of Lage Grande, casting unlikely that a depositional agent with sedimentary capacity doubts on the pervasiveness of the hypothesis of an arid climate limited to sand-sized clasts could have been able to transport large operating widely on the whole Brazilian Intertropical Region dur- bones. Close up of the trample marks; B. Fibula of N. Conclusions the fossildiagenesis, when the elements were differentially impregnated by opaque minerals.
The occurrence of several The LGPS taphocoenosis represents a fossil vertebrate accumu- impregnation processes in the taphocoenosis seems unlikely lation that is less taphonomically biased in comparison to other because there is no evidence of reworking based only on macro- similar deposits.
Comparing the fossils with others composition and relative abundance may be more reliable con- of similar color from other late Pleistocene deposits Santos et al. Rapid burial is inferred based on the high quality of mineralogical impregnation during the fossilization, only the physical integrity of the fossils. There- Overall, the preservational aspects of the Lage Grande deposit fore, tank deposits may differ in the quality of paleoecological in- differ considerably from the expected taphonomic pattern for tank formation preserved in their fossil accumulations.
Tanks with steeper edges show more E. In Lage Grande, The results of this analysis casts doubt on the assumption that the the tanks are pond-like, presenting less steep edges, not forming fossil assemblages of tank deposits are dominated by fossil frag- vertical slopes, and are covered by clastic sediments.
Pond-like ments and poorly preserved skeletal elements, showing that tanks had better conditions for skeletal element preservation in marked differences in the preservational quality occur among tank contrast to those with more steep edges.
Nevertheless, new deposits. The contrasting stratigraphic succession observed for the comparative studies should be performed in order to evaluate this tank of LGPS is another example of how the tanks can differ in hypothesis.
Extinction of a gomphothere pop- settings e. Quaternary International , 85e Palaios 1, e The taphonomy and paleoecology of Plio-Pleistocene accumulation is the unusual morphology of this deposit, which is vertebrate assemblage east of Lake Rudolf, Kenya. Bulletin of the Museum of pond-like, unlike most other tank deposits. The morphology of the Comparative Zoology , e Paleobiology 4, e Allison, P. Plenum Press, New York, pp.
Acknowledgments Behrensmeyer, A. Trampling as a cause of bone surface damage and pseudo-cutmarks. Nature , e The authors thank D.
Paleoenvironmental contexts and tapho- nomic modes. Sues, H. Evolutionary Barbosa, A.
Ghilardi, T. Aureliano-Neto, C. Rangel, T. Metello, Paleoecology of Terrestrial Plants and Animals. University of Chicago Press, P. Pereira and L. LGPS; to C. Almeida for identifying the basement rock samples Behrensmeyer, A. Paleobiology 11, e Scherer and E. Oliveira for identifying some Behrensmeyer, A. Taphonomy and paleobi- specimens studied here; to P.
Erwin, D. The Paleontological Society, pp. Revista Brasileira de Paleontologia 14, 75e Appendix A. Britt, B. Palaeogeography, Palae- dx. Cabral-de-Carvalho, J. Arquivos do Instituto de Antropologia 2, e Cartelle, C. Pleistocene mammals of the Cerrado and Caatinga of Brazil. Process and Bias through Time, 2a Eisenberg, J. Springer, New York, pp. The University of Chicago Press, Chicago, pp.
Alves, R. Macraucheniidae Mammalia, Litopterna do Pleistoceno do Brasil. Amaral, R. Post-graduate Monograph. Ameghiniana 41, e Cruz, L. Ameghiniana 44, e Universidade Federal do Rio de Janeiro, Brazil.
Cruz, M. Scientia Plena 3, 30e Fazenda Elefante, Gararu, Sergipe, Brasil. Romano, P. Marcas de dentes de car- Sociedade Brasileira de Paleontologia, Recife, p.
Revista Eberth, D. A practical approach to the study of Brasileira de Paleontologia 14, e The University of Chicago Press, taphonomy of elusive natural tank deposits: Palaeogeography, Palaeoclimatology, Palaeoecology , Eberth, D. A bonebeds database: Tapho- Eds. Carnivore competition, bone 26e Journal of Archaeological Science 34, e Auler, A. Neves, W. Body mass estimations in Lujanian Late vertebrates from Brazilian caves. Masto- oecology , e Current Paula-Couto, C.
Fossil Pleistocene to sub-recent mammals from northeastern Research in the Pleistocene 1, 47e Taphonomy of Hazard homestead Quarry Ogallala group , e Hitchcock County, Nebraska. Contributions to Geology 26, 57e Novos achados de Panochthus Mammalia, Fiorillo, A. Taphonomy and depositional setting of careless Creek Quarry Cingulata, Glyptodontoidea no nordeste do Brasil.
Palaeogeography, ontologia 4, 51e Palaeoclimatology, Palaeoecology 81, e A new cingulate Mammalia: Taphonomy and Archae- Xenarthra , Pachyarmatherium brasiliense sp.
Journal of Vertebrate Paleontology 29, e Incontro Annuale di Istudi. Revista de Geologia 15, 17e Geobios 37, e Paleoecology of the large carnivore guild from the Hanson, C. Fluvial taphonomic processes: Acta Palaeontologia Polonica 51, e Vertebrate Ribeiro, R. Midway Reprint, Chicago, pp. Master dissertation. Uni- Haynes, G. Paleobiology 6, e Pesqueira, Pernambuco, Brasil. Cambridge de Paleontologia. Universidade Federal do Acre, Acre, Brasil, p.
University Press, Cambridge, pp. Henriques, D. University of Chicago Press, Chicago. Revista Holland, S. The quality of the fossil record: Paleobiology 26, e Paleobiogeography of Holz, M. Editora da the late Pleistocene pampatheres of South America. Earth Sciences 20, e Taphonomy e overview of main concepts and ap- Shipman, P. Koutsoukos, E. Harvard University Press, Cambridge.
Applied Stratigraphy. Butchering of giant geladas at an Holz, M. Current Anthropology 46, 77e Silva, F. Hutson, J. Reanalysis and reinterpretation of the Kalkbank fauna accu- Silva, J.
Journal of Taphonomy 6, e Neotaphonomic measures of carnivore serial predation at Ph. Universidade Federal de Pernambuco, Brazil. Ngamo Pan as an analog for interpreting open-air faunal assemblages. Cambridge University Press, Cambridge. Madgwick, R. Investigating variation in the prevalence of Simpson, G. The Mastodonts of Brazil.
Bulletin of the weathering in faunal assemblages in the UK: American Museum of Natural History , e International Journal of Osteoarchaeology 22, e Boletim do Museu Nacional 6, 1e Moore, K. Guanabara Koogan, Rio de Vidal, N. Estudo descritivo e comparativo de Macrauchenia patachonica Owen Janeiro. Boletim do Museu Nacional 21, 1e Revision of the Quaternary Vidal, N.
Um Toxodon no Pleistoceno de Pernambuco. Boletim do Museu South America lowland gomphotheres Mammalia: Gompho- Nacional 30, 1e Quaternary International e, 2e7. Evaluating habitats and Noto, C. Hierarchical control of terrestrial vertebrate taphonomy over space feeding habits through ecomorphological features in glyptodonts Mammalia, and time: Ameghiniana 48, e Process and Bias Through Voorhies, M. Fauna, Knox County, Nebraska.
Journal of Archaeological Science 15, e Zurita, A. The Pleis- Patzkowsky, M. Stratigraphic Paleobiology: Understanding tocene Glyptodontidae Gray, Xenarthra: Revista Brasileira de Press, Chicago.
Paleontologia 15, e Research Paper Keywords: Corresponding Author's Institution: Order of Authors: Fossils were collected from a tank deposit, the most singular sedimentary deposit bearing Quaternary vertebrates of South America.
This analysis also provides taphonomic and paleoecological data obtained through the application of common multivariate techniques.
Llewellyn Ivor Price
Furthermore, this analysis also provides estimatives of time- and spatial resolution for debris-flow deposits. This analysis shows that, although the CPS assemblage has experienced an array of taphonomic processes, the transportation was the main process controlling the taphonomic pathway of the thanatocoenosis during the biostratinomic phase, unleashing the co-ocurrence of other processes, such as abrasion, fragmentation and modifications in the bone and taxonomic representativeness.
The origin of the taphonomic modes of vertebrates in the tank deposit of CPS can have been controlled by three major taphonomic phenomena: Furthermore, the analysis of these taphonomic modes has corroborated a previous hypothesis: The time and spatial resolutions in debris-flow accumulations based on the analysis of tank deposits and their comparison with other comparable gravitational deposits indicates a time resolution from hours to ten of thousand of years and a local resolution, respectively.
This pioneer estimate can be used as a basis for future estimates of paleontological resolution in bearing-fossil debris-flow deposits. Suggested Reviewers: Moore is a taphonomist and paleoecologist interested in how statistic analyses e.
Universidade Federal da Bahia matdantas yahoo. Alcina M F Barreto D. Universidade Federal de Pernambuco alcina ufpe. Claudia I Montalvo D. Universidad Nacional de La Pampa cmontalvo exactas.
Furthermore, we describe and use a new method based on multivariate analyses for establishing taphonomic modes in vertebrate fossil assemblages.
This method will be useful for any paleontologist vertebrates, invertebrates, micropaleontologists and paleobotanists interested in Taphonomy and Paleoecology. These deposits are small depressions developed in basement rocks and that during the Late Pleistocene were filled by terrigenous sediments and skeletal remains of Pleistocene megafauna. These deposits, so far only have been found at Northeastern Brazil.
It is of great interest that the Taphonomy and Paleoecology of Late Pleistocene vertebrates from tank deposits of Brazil and our new method can be known through the publication of this manuscript in Palaeogeography, Palaeoclimatology, Palaeoecology. Manuscript Click here to download Manuscript: Araujo-Junior et al. Athos da Silveira Ramos, , 10 Fossils were collected from a tank 20 deposit, the most singular sedimentary deposit bearing Quaternary vertebrates of South 21 America.
This analysis also provides taphonomic and paleoecological data obtained 23 through the application of common multivariate techniques. Furthermore, this analysis also 24 provides estimatives of time- and spatial resolution for debris-flow deposits. The origin of the taphonomic modes of 31 vertebrates in the tank deposit of CPS can have been controlled by three major taphonomic 32 phenomena: The 37 time and spatial resolutions in debris-flow accumulations based on the analysis of tank 38 deposits and their comparison with other comparable gravitational deposits indicates a time 39 resolution from to years and a local resolution, respectively.
This pioneer estimate 40 can be used as a basis for future estimates of paleontological resolution in bearing-fossil 41 debris-flow deposits.
Taphonomy; Paleoecology; Quaternary mammals; Tank deposit; Brazil. These analyses 51 have allowed the understanding of paleobiological, taphonomic and depositional data from 52 different kinds of Quaternary vertebrate deposits. A 54 surface bone modifications Santos et al.
Furthermore, some analyses e. Tomassini et al. The tanks consist of natural 69 depressions developed on basement rock outcrops by physical-chemical weathering. However, up to now, these latter seem to be 78 unfossiliferous. Nevertherless, some 82 of the most important and iconic tank deposits lack detailed taphonomic analyses, including 83 those described in classic studies of Carlos de Paula Couto Paula-Couto, , This analysis contributes to improve the knowledge on taphonomic pathways, 91 preservational modes and paleoecology of Quaternary vertebrates of the Brazilian 92 Intertropical Region BIR and on the preservational quality and depositional processes in 93 tank deposits.
The tank is oval, of At the time of the survey, the tank was filled with pluvial water, precluding any measurement of its depth, which, according to Paula-Couto , is about 4 m. Regrettably, because the tank deposit of CPS has been fully excavated in , we could not collect new stratigraphic and sedimentological data in the survey.
He also offered a brief sedimentological description of the deposit Paula-Couto, Carnivora, Felidae. Such study revealed the occurrence of taphonomic biases on the genesis of the Quaternary vertebrate accumulations of the tank deposits.
The dataset used comprises specimens the whole material collected in CPS. The specimens classified at family or subfamily levels by those authors were here assigned to specific or generic levels.
This taxonomic revision was based on comparisons with other specimens housed in MN and with elements figured in the paleomastozoological literature. A numerical dating on remains of X.
However, preservational considerations from previous papers regarding the Quaternary mammals of CPS e. Paula-Couto, ; Bergqvist, ; Bergqvist, ; Bergqvist et al. A taxonomic composition; B physical integrity assessment of the degrees of completeness of the skeletal elements ; C disarticulation; D bone representativeness; E breakage; F weathering; G abrasion; H trampling; I tooth marks; J invertebrate modifications; K rooting; and L color and impregnation patterns.
For each taxon, the Minimum Number of Individuals MNI was calculated according to Badgley and Lyman , by using the most abundant skeletal element from either the left or right side of the animal Lyman, Whenever possible, specimens were classified as subadult or adult, based on: These analyses allow the assessment of the bioclast sorting during the transport and the degree of transportation of the thanatocoenosis, respectively.
Finally, values of hydraulic equivalence proposed by Behrensmeyer were used in order to recognize the hydraulic equivalence between sizes of both bones and sediments allowing better inferences on hydraulic transportation. The significance value p of the clusterings was also obtained from this test. All multivariate analyses were performed in the software Paleontological Statistics version 2. In this scoring, the rows include the taxa and the collumns represent the categories of taphonomic signatures.
The stages of weathering have not been established for taxa recorded only by teeth, which in the present case include Notiomastodon platensis, Toxodon platensis, Equus Amerhippus neogaeus and Hippidion principale or osteoderm of carapace Holmesina paulacoutoi so that they were scored as missing entries? We carried out two distinct cluster analyses: According to Hammer et al.
In the case of this taphonomic analysis, if the data are well behaved, taxa typical for a taphonomic set should plot in the vicinity of that association. The estimated mass for each species was taken from previous studies e. The terms biocoenosis, thanatocoenosis and taphocoenosis follow Lyman A biocoenosis, life assemblage; B thanatocoenosis, death assemblage, derived from the biocoenosis and subsequently modified by biostratinomic processes; and C taphocoenosis, buried and preserved assemblage.
Terms autochthonous, parautochthonous, allochthonous, local assemblages and regional assemblages are according to Behrensmeyer and Hook A autochthonous, a non-transported fossil assemblage; B parautochthonous, a transported fossil assemblage, but preserved within its habitat area; C allochthonous, fossil assemblage transported and preserved outside its habitat area; D local, assemblages that represent areas and life habitats proximal to the depositional site; and C regional, assemblages derived from larger areas, up to entire drainage basins.
We follow Lyman in the use of the terms specimen and skeletal element: Finally, we use the terminologies of Behrensmeyer for degrees of physical integrity: Among fossils collected at CPS, we identified specimens belonging to megamammals and large- and small-sized mammals Tab. Xenarthra, Pilosa, Mylodontidae; Fig. Carnivora, Felidae; Fig. The morphology of the two metacarpi and tooth assigned to Scelidotheriinae indet. The lumbar vertebra of Felidae was attributed to Pantherinae indet.
This specimen may belong to Panthera onca Linnaeus, , though a more conclusive assignment should be based on teeth and cranial bones Morgan and Seymour, The fragment of femur of the small-sized felid was identified as Leopardus sp. A specific assignment is impossible due to the lack of diagnostic characters in the femur of small felines included in Leopardus. Specimens identified by Bergqvist et al.
The osteoderms of carapace attributed by Bergqvist et al. The scarcest taxa are H. Regarding the MNI, X. All other taxa have MNI values equal to 1. Some of the specimens belonging to the taxa recorded in CPS are figured Figs. Atlas, sacrum, hemal arch, caudal ring, humerus, ulna and patella are the scarcest. The mandibles are fragmented, though some of them bear teeth in their alveolus.
Vertebrae are represented mainly by vertebral centra, though almost complete specimens are also preserved. Cranium, axis, scapula and fibula are absent. See the Fig. Long and flat bones are underrepresented, representing The long bones are fragmented and represented mainly by distal and proximal ends The percentage of the skeletal elements according to the FTI groups Frison and Todd, is presented in the Fig.
The association of bones showing wide variation in shape, size and weight e.
Britt et al. Almost all long bones are fragmented, except two phalanges of P. Flat bones group consists of fragmented and partial specimens Partial specimens belong to E. According to the criteria established by Shipman et al. A irregular fractures, perpendicular to long bone axis Smooth fractures perpendicular to long bone axis, as well as columnar fractures, were not observed. Oblique fractures were observed on a single specimen belonging to X.
Long bones without breaks belong to P. We did not observe specimens with stages 3, 4 and 5 of weathering. In the stage 1 are specimens attributed to E.
Specimens with moderate abrasion pertain to E. Heavy-abraded specimens belong to E.
This process is more visible on the specimens with black color 2. The R-mode cluster analysis revealed both the most common categories of taphonomic features and the most exotic ones in the assemblage Fig. Mode M2 includes N. Mode M3 comprises Panochthus sp. Finally, mode M4 includes Glossotherium sp. The other taphonomic modes, taken as a whole, account for Such exotic characteristics are: Inversely, the group T2 includes the most common categories of the assemblage: The groups T3, T4 and T5 are composed of sets of co-occurring taphonomic categories: In the case of CPS, the patterns of weathering and abrasion and the inferred degree of transportation see 6.
We consider unlike that this abundance was caused by taphonomic processes because other large-sized mammals with body mass comparable to a macraucheniid e.
Furthermore, camelids share most of their same taphonomic attributes with X. Thus, the abundance of X. Unfortunately, the lack of studies regarding the paleobiology and paleoecology of such taxon precludes any sound interpretation of its abundance in CPS.
Despite of their scarcity or even absence in some deposits e. Excepting X. In turn, the occurrence of subadult individuals of X. The remarkable variation in the degrees of taphonomic modifications observed in the specimens assigned to X. This difference may be due to differences in age or in paleoenvironmental conditions relative to other deposits in northeastern Brazil.
Absolute datings would be necessary to settle the age and to quantify the time-averaging of the fauna of CPS, though its taxonomic similarity with other tank accumulations in Brazil seems to make the former hypothesis less likely.
However, recent studies have demonstrated that the original amount of vertebrae, ribs, isolated teeth and phalanges can be severelly reduced during the biostratinomic phase Arcos et al. Ribs are transported through significantly shorter distances than other bones of similar weight due to their long and slender shape, which hinders transportation Aslan and Behrensmeyer, Besides the aforementioned overrepresented elements, long bones, such as humeri, femurs and tibiae — which generally undergo a light reduction in their quantities Arcos et al.
Such pattern can indicate that the CPS thanatocoenosis experienced: Commonly, trampling, weathering and transportation are the causes of such breakage Myers et al.
On the other hand, the degree of fragmentation observed in CPS assemblage Such interpretations were based on the evaluation of both biostratinomic and fossildiagenetic features. In the case of CPS, though the percentage of fragmentation is intermediary, the high amount of bones showing a single color and the lack of bones with diagenetic fractures are suggestive of a low degree of reworking.
However, as suggested by Behrensmeyer , it is unlikely that physical transport alone can cause a large degree of fragmentation. For this reason, we consider that, besides transport, other physical processes may have fragmented the bones, even some that have not other additional evidence of occurrence in the deposit, such as trampling and scavenging. African large-sized mammalian assemblages presenting such pattern are a result of five years of weathering Behrensmeyer, When compared to other tank deposits e.
The huge amount of fossils exhibiting some degree of abrasion supports this idea Fiorillo, ; Behrensmeyer, ; Eberth et al. Furthermore, debris flows do not necessarily need to flow through long distances Dasgupta, in order to cause a so marked abrasion. Assuming that most of the breaks were produced prior to burial, it is likely that the specimens have been transported when they were in their current dimensions.
In this scenario, the small dimension of the specimens may have allowed the transportation under a low energy regime. In most tank deposits known so far, the stratigraphic, sedimentological and taphonomic attributes indicate a deposition in a debris-flow regime Galindo et al. Although gravitational and fluvial systems are very distinct, some interpretations can be made based on the conclusion of Aslan and Behrensmeyer We carried out two distinct cluster analyses: Multivariate analyses using percentages of specimens according to taphonomic categories for each tank deposit; A.
Models for the Rise of the Dinosaurs. Boletim de Resumos da Paleo Nordeste Polish Polar Research 13— Taxonomic definitions and terminology. In the case of CPS, the patterns of weathering and abrasion and the inferred degree of transportation see 6. Rapid burial is inferred based on the high quality of mineralogical impregnation during the fossilization, only the physical integrity of the fossils.
Megafauna do Pleistoceno Universidade Guarulhos, 7:
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