Taphonomy
The archaeological site of Pego (Braga, NW of Portugal) highlights the limits and possibilities of charcoal analysis in Bronze Age sites with long and recurrent occupations (Sampaio et al. 2008, Sampaio and Bettencourt 2011, 2014; Sampaio... more
The archaeological site of Pego (Braga, NW of Portugal) highlights the limits and possibilities of charcoal analysis in Bronze Age sites with long and recurrent occupations (Sampaio et al. 2008, Sampaio and Bettencourt 2011, 2014; Sampaio 2014). The site was occupied since the end of the Early to Late Bronze Age.
Its earliest features of this site are located in Sector II, a plain grave’s necropolis dating to the end of the Early to Middle Bronze Age was found. Probably with intentional depositional purposes, during Middle-Late Bronze Age this area was used for digging few pits covered with weathered granite. Near it, in sector V (on the top of the hill), there was identified a fireplace and at least four pits (pits 1, 3, 18 and 19) linked to an occupation of this area also dating back to the Middle Bronze Age. In the same area, several other pits and post-holes, small ditches and a perimetral ditch (comprising a palisade) were also identified. In many cases some of these structures date back to Late Bronze Age. The assemblages considered were mostly recovered from secondary contexts, something usual in these Bronze Age sites. This fact connected with the recurrent occupation of the sample’s place during long periods of time complicates the interpretation of charcoal analysis outcomes. In these cases we consider that it is essential to go beyond taxonomic identification considering also taphonomical and dendrological attributes. At the same time this methodology can help identifying different site’s moments of occupation.
Sampaio, H. A., 2014. A Idade do Bronze na bacia do rio Ave (Noroeste de Portugal). Braga: University of Minho.
Sampaio, H. A., Bettencourt, A. M. S., 2011. Produção e práticas metalúrgicas da Idade do Bronze no Noroeste Português: o caso do Pego. In: Martins, C. M. B., Bettencourt, A. M. S., Martins, J. I. P.F. and Carvalho, J., Povoamento e Exploração dos Recursos Mineiros na Europa Atlântica Ocidental, Braga: CITCEM/APEQ, pp. 391-407.
Sampaio, H. A., Bettencourt, A. M. S., 2014. Between the valley and the hill top. Discoursing on the spatial importance of Pego’s Bronze Age necropolis, Braga (Northwest of Portugal). Estudos do Quaternário/Quaternary Studies, 10: 45-57.
Sampaio, H. A., Bettencourt, A. M. S., Barbosa, R., Dinis, A., Cruz, C., 2008. A importância do povoado do Pego no Bronze Final do Noroeste de Portugal. Férvedes, 5: 227-233.
Its earliest features of this site are located in Sector II, a plain grave’s necropolis dating to the end of the Early to Middle Bronze Age was found. Probably with intentional depositional purposes, during Middle-Late Bronze Age this area was used for digging few pits covered with weathered granite. Near it, in sector V (on the top of the hill), there was identified a fireplace and at least four pits (pits 1, 3, 18 and 19) linked to an occupation of this area also dating back to the Middle Bronze Age. In the same area, several other pits and post-holes, small ditches and a perimetral ditch (comprising a palisade) were also identified. In many cases some of these structures date back to Late Bronze Age. The assemblages considered were mostly recovered from secondary contexts, something usual in these Bronze Age sites. This fact connected with the recurrent occupation of the sample’s place during long periods of time complicates the interpretation of charcoal analysis outcomes. In these cases we consider that it is essential to go beyond taxonomic identification considering also taphonomical and dendrological attributes. At the same time this methodology can help identifying different site’s moments of occupation.
Sampaio, H. A., 2014. A Idade do Bronze na bacia do rio Ave (Noroeste de Portugal). Braga: University of Minho.
Sampaio, H. A., Bettencourt, A. M. S., 2011. Produção e práticas metalúrgicas da Idade do Bronze no Noroeste Português: o caso do Pego. In: Martins, C. M. B., Bettencourt, A. M. S., Martins, J. I. P.F. and Carvalho, J., Povoamento e Exploração dos Recursos Mineiros na Europa Atlântica Ocidental, Braga: CITCEM/APEQ, pp. 391-407.
Sampaio, H. A., Bettencourt, A. M. S., 2014. Between the valley and the hill top. Discoursing on the spatial importance of Pego’s Bronze Age necropolis, Braga (Northwest of Portugal). Estudos do Quaternário/Quaternary Studies, 10: 45-57.
Sampaio, H. A., Bettencourt, A. M. S., Barbosa, R., Dinis, A., Cruz, C., 2008. A importância do povoado do Pego no Bronze Final do Noroeste de Portugal. Férvedes, 5: 227-233.
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Tinkinswood chambered tomb, an earlier Neolithic burial monument located in Glamorgan, has not been thoroughly reanalysed since its excavation in 1914. Keith’s (1916) assessment of the human remains estimated the burial of 50 individuals... more
Tinkinswood chambered tomb, an earlier Neolithic burial monument located in Glamorgan, has not been thoroughly reanalysed since its excavation in 1914. Keith’s (1916) assessment of the human remains estimated the burial of 50 individuals within the chamber. Recent work acknowledges that higher numbers of burials were made in transepted chambered tombs, for example with 36 individuals at West Kennet, relative to single chamber tombs. The high MNI for Tinkinswood is therefore unlikely considering the small, single chamber. As such, reanalysis of the human remains is timely and important.
The assemblage is highly fragmented and commingled, with no complete individuals preserved and many fragile elements unexcavated. No evidence was found for cutmarks or canid gnawing, suggesting that most burials were complete inhumations. Taphonomic analysis reveals that most breaks occurred on dry bone, implying time lapses between successive burials and the disturbance of older remains. Importantly, the MNI can be revised to about 20 individuals with evidence for 10 adults, at least 8 sub-adults and up to 2 cremations.
The long-held interpretation for an expression of corporate identity in single chambered tombs has hinged on the nature of deposits as disarticulated (Thomas, 1999: 150). Considering the lack of evidence for anthropogenic breaking down of corpses prior to burial at Tinkinswood it seems likely that individuals were maintained in death. Furthermore, whilst we cannot fully assess the evidence for the rearrangement of skeletons, the indication for removal of bones is low. This paper summarises the recent analysis within a theoretical funerary framework.
The assemblage is highly fragmented and commingled, with no complete individuals preserved and many fragile elements unexcavated. No evidence was found for cutmarks or canid gnawing, suggesting that most burials were complete inhumations. Taphonomic analysis reveals that most breaks occurred on dry bone, implying time lapses between successive burials and the disturbance of older remains. Importantly, the MNI can be revised to about 20 individuals with evidence for 10 adults, at least 8 sub-adults and up to 2 cremations.
The long-held interpretation for an expression of corporate identity in single chambered tombs has hinged on the nature of deposits as disarticulated (Thomas, 1999: 150). Considering the lack of evidence for anthropogenic breaking down of corpses prior to burial at Tinkinswood it seems likely that individuals were maintained in death. Furthermore, whilst we cannot fully assess the evidence for the rearrangement of skeletons, the indication for removal of bones is low. This paper summarises the recent analysis within a theoretical funerary framework.
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To distinguish whether the presence of osteoderms of armadillos (Xenarthra, Dasypodidae) in the zooarchaeological and paleontological record can be assigned to anthropic action or predators is an interesting topic. The Crowned solitary... more
To distinguish whether the presence of osteoderms of armadillos (Xenarthra, Dasypodidae) in the zooarchaeological and paleontological record can be assigned to anthropic action or predators is an interesting topic. The Crowned solitary eagle (Buteogallus coronatus, Accipitriformes, Accipitridae) is among the predators that usually consume armadillos. It is one of the largest South American birds of prey, inhabiting southern Brazil to northern Patagonia in Argentina. Prey remains of the armadillos Zaedyus pichiy, Chaetophractus villosus and C. vellerosus were collected in 13 breeding areas from two
biogeographic regions including La Pampa and Mendoza provinces, central Argentina, during 2010-2012. The significant amount of carapaces, osteoderms, and cranial elements of armadillos accumulated in nests is a distinctive feature of the Crowned solitary eagle. These accumulations are taphonomically characterized by the presence of: 1) complete or almost complete flattened, depressed or book-shaped
folded carapace; 2) scarce caudal armors and cephalic shields; 3) flexible bands, and scapular and pelvic shields well represented; 4) anterior region of scapular shields usually broken; 5) many isolated osteoderms broken, crenulated or with irregular borders; 6) posterior regions of skulls often with
crenulated, broken or missing borders; 7) skulls with beak marks in the dorsal and posterior parts of the braincase, and in the palates; 8) some mandibles with the posterior part broken; 9) scarce, but well preserved limb bones; and 10) beak marks on scapulae and pelves. In addition, the information obtained
from abandoned nests showed that these taphonomic features could have been altered by weathering. These observations can be used in subsequent studies of armadillo bone accumulations from open-air archaeological or paleontological sites from central Argentina, and other parts of America, inhabited by the Crowned solitary eagle, as well as in future revisions of samples.
biogeographic regions including La Pampa and Mendoza provinces, central Argentina, during 2010-2012. The significant amount of carapaces, osteoderms, and cranial elements of armadillos accumulated in nests is a distinctive feature of the Crowned solitary eagle. These accumulations are taphonomically characterized by the presence of: 1) complete or almost complete flattened, depressed or book-shaped
folded carapace; 2) scarce caudal armors and cephalic shields; 3) flexible bands, and scapular and pelvic shields well represented; 4) anterior region of scapular shields usually broken; 5) many isolated osteoderms broken, crenulated or with irregular borders; 6) posterior regions of skulls often with
crenulated, broken or missing borders; 7) skulls with beak marks in the dorsal and posterior parts of the braincase, and in the palates; 8) some mandibles with the posterior part broken; 9) scarce, but well preserved limb bones; and 10) beak marks on scapulae and pelves. In addition, the information obtained
from abandoned nests showed that these taphonomic features could have been altered by weathering. These observations can be used in subsequent studies of armadillo bone accumulations from open-air archaeological or paleontological sites from central Argentina, and other parts of America, inhabited by the Crowned solitary eagle, as well as in future revisions of samples.
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Microbial mats have been repeatedly suggested to promote early fossilization of macroorganisms. Yet, experimental simulations of this process remain scarce. Here, we report results of 5 year-long experiments performed onfish carcasses to... more
Microbial mats have been repeatedly suggested to promote early fossilization of macroorganisms. Yet, experimental simulations of this process remain scarce. Here, we report results of 5 year-long experiments performed onfish carcasses to document the influence of microbial mats on mineral precipitation during early fossilization. Carcasses were initially placed on top of microbial mats. After 2 weeks, fish became coated by the mats forming a compact sarcophagus, which modified the microenvironment close to the corpses. Our results showed that these conditions favored the precipitation of a poorly crystalline silicate phase rich in magnesium. This talc-like mineral phase has been detected in three different locations within the carcasses placed in microbial mats for more than 4 years: (1) within inner tissues, colonized by several bacillary cells; (2) at the surface of bones of the upper face of the corpse buried in the mat; and (3) at the surface of several bones such as the dorsal fin which appeared to be gradually replaced by the Mg-silicate phase. This mineral phase has been previously shown to promote bacteria fossilization. Here we provide first experimental evidence that such Mg-rich phase can also be involved in exceptional preservation of animals.
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Research Interests: Zooarchaeology, Archaeozoology, Archaeological Method & Theory, Survey (Archaeological Method & Theory), Taphonomy, and 21 moreArchaeological Theory, Archaeological theory and practice, Carnivore Taphonomy, History of Archaeology, Archaeological Method and Theory, International council of Archaeozoology, Vertebrate taphonomy, Avian taphonomy, Bone diagenesis and taphonomy, Taphonomy and Paleoecology, Patagonia zooarchaeology, Cave Taphonomy, Archaeozoology, Taphonomy, Faunal Analysis, Zooarchaeology, Actualistic Studies in Taphonomy, Archaeology, zooarchaeology and taphonomy, ICAZ, Excavation Theory, Taphonomy, and Site Formation Processes, History of Archaeological Theory, Archaeology - Archaeozoology, and ARCHAEZOOLOGY AND TAPHONOMY
Research Interests: Zooarchaeology, Taphonomy, Carnivore Taphonomy, History of Archaeology, Vertebrate taphonomy, and 8 moreAvian taphonomy, Taphonomy and Paleoecology, Patagonia zooarchaeology, Archaeozoology, Taphonomy, Faunal Analysis, Zooarchaeology, Actualistic Studies in Taphonomy, ICAZ, and ARCHAEZOOLOGY AND TAPHONOMY
Leopard remains are rare in the European fossil record, probably a consequence of its solitary and elusive habits. Equi, dating back to Marine Isotope Stage 3 (MIS3), represents a rich and outstanding exception. Historical excavations... more
Leopard remains are rare in the European fossil record, probably a consequence of its solitary and elusive habits. Equi, dating back to Marine Isotope Stage 3 (MIS3), represents a rich and outstanding exception. Historical excavations (from 1911 to about 1917) at Equi allowed more than 200 remains to be recovered of this large felid, a sample attesting the richest leopard-bearing site in the Pleistocene of Europe. The Equi site testifies the survival of a prosperous leopard population in northwestern Italy (the Apuan Alps
area) during the pre Last Glacial Maximum Late Pleistocene.
Almost all skeletal elements are represented in the collection (except ribs, and most of axial skeleton). At Equi, leopard is represented by both young and adult animals and, up to now, it seems the first and unique Pleistocene evidence of cave usage for cubs raised in Europe. This study focuses on the whole record of leopard from Equi, housed in the Museum of Natural History of Florence, and is aimed to analyze the taphonomical assemblage, to provide an anatomical description of the remains and the comparison to the European evidences. Moreover, we infer the paleoecology of leopards, and their relationships with other large carnivores from the Equi guild (Ursus spelaeus, Canis
lupus, and Panthera leo spelaea). The site was probably an occasional large carnivores den, used over time by different large carnivore taxa, perhaps in different seasons or times (mutual avoiding). Our morphological analysis allows us to recognize sexual dimorphic characters in the cranium, and a large morphological variability in body size.
area) during the pre Last Glacial Maximum Late Pleistocene.
Almost all skeletal elements are represented in the collection (except ribs, and most of axial skeleton). At Equi, leopard is represented by both young and adult animals and, up to now, it seems the first and unique Pleistocene evidence of cave usage for cubs raised in Europe. This study focuses on the whole record of leopard from Equi, housed in the Museum of Natural History of Florence, and is aimed to analyze the taphonomical assemblage, to provide an anatomical description of the remains and the comparison to the European evidences. Moreover, we infer the paleoecology of leopards, and their relationships with other large carnivores from the Equi guild (Ursus spelaeus, Canis
lupus, and Panthera leo spelaea). The site was probably an occasional large carnivores den, used over time by different large carnivore taxa, perhaps in different seasons or times (mutual avoiding). Our morphological analysis allows us to recognize sexual dimorphic characters in the cranium, and a large morphological variability in body size.
Research Interests:
Research Interests:
Ao caminhar pela praia, é comum encontrarmos remanescentes biológicos de animais marinhos. Entre eles destacam-se as conchas de moluscos. Assumimos intuitivamente que essas conchas são o registro fiel de indivíduos que viveram em áreas... more
Ao caminhar pela praia, é comum encontrarmos remanescentes biológicos de animais marinhos. Entre eles destacam-se as conchas de moluscos. Assumimos intuitivamente que essas conchas são o registro fiel de indivíduos que viveram em áreas marinhas próximas e que elas foram transportadas até a praia pelas ondas após a morte do molusco. No entanto, as conchas vistas na areia não necessariamente vieram de espécies vivas na atualidade: podem ser também de espécies que viveram de dezenas a muitos milhares de anos antes do presente. Essa variada coleção biológica é, portanto, fonte de informações relevantes para a ciência.
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The use of rocky intertidal assemblages in paleoecology and conservation paleobiology studies is limited because these environments have low preservation potential. Here, we evaluate the fidelity between living intertidal mussel bed... more
The use of rocky intertidal assemblages in paleoecology and conservation paleobiology studies is limited because these environments have low preservation potential. Here, we evaluate the fidelity between living intertidal mussel bed communities (life assemblages or LAs) and mollusk shell accumulations (death assemblages or DAs) from the environmentally harsh Patagonian Atlantic Coast. LAs were sampled from rocky mid-intertidal and mussel-dominated habitats while DAs were collected from the high water mark at beaches in close proximity to the living intertidal community to assess live-dead mismatch at regional scales. DAs were restricted to the subset of species in the DAs that inhabit rocky intertidal habitats. A total of 37,193 mollusk specimens from 15 intertidal species were included in the analysis. Ten species were present in LAs, 14 in DAs, and nine were shared by LAs and DAs. DAs showed higher diversity, less dominance, and more rare species than LAs. Despite finding good agreement in species composition between DAs and LAs within the same region, smaller species are underrepresented, as shown by differences in size-frequency distributions. Our findings indicate that the composition of DAs is a result of the combined effects of spatial and temporal averaging, size-related biases, and biases related to low detectability of boring and vagile species in LAs. Thus, DAs do not accurately detect within-provincial latitudinal gradients in composition. However, DAs clearly capture differences between the Argentine–Magellanic Transition Zone and the Magellanic Province, indicating that DAs are informative tools at regional scales despite the environmental harshness to which they are subjected.
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While low sedimentation rates favor the formation of fossil concentrations, by lowering the sedimentary dilution of dead remains, it can also enhance the destruction at the sediment-water interface, by prolonging the residence of fossils... more
While low sedimentation rates favor the formation of fossil concentrations, by lowering
the sedimentary dilution of dead remains, it can also enhance the destruction at the
sediment-water interface, by prolonging the residence of fossils in the taphonomically
active zone (TAZ). Shelly (mollusk) concentrations in the marine realm are associated
to stratigraphic discontinuities, which may be bedding planes or unconformities,
allowing suggesting that shifts in the sedimentation style determine the properties of
the skeletal concentration. In the marine setting, shell-beds usually develop in
stratigraphically predictable areas such as sequence boundaries (e.g., downlap
deposits at the base of highstand system tracts, backlap deposits at distal maximum
flooding surfaces, toplap deposits at the top of highstand system tracts, and so on).
The Southern Brazil Shelf (within latitudes 27ºS and 34ºS) is a sediment-starved
passive margin continental shelf, with bioclast concentrations associated to possible
ancient coastlines that might be formed in coordination to wave ravinement surfaces. In
addition, several deposits are also present in areas with no relation to previous sealevel
stabilization areas, where the sediment is mainly constituted by relictual
(~reworked) sand. Fourteen mollusk shell samples from near shelf-break deposits (the
“distal shell-rich” group), eleven mollusk shell samples from proximal, low depth
bioclastic deposits (the “proximal shell-rich” group) and ten samples from sandy
substrate (the “shell-poor” group) were evaluated for taphonomic damage accordingly
to updated taphonomic protocols. This analysis was conducted in order to determine to
which degree de taphonomic properties of recent, developing shelly concentrations in
fact might be related to the position within a sequence stratigraphy framework. Using
multivariate statistical analysis (mainly non-metric multidimensional scalling and
multivariate analysis of variance with permutation) we determined that the three groups
of shell samples in fact are significantly different. The distal deposit is dominated by
low-intensity damage (natural bright and ornamentation); the inverse occurs to the
proximal deposit (samples from the shell-poor area present an intermediate damage
pattern). The taphonomic condition of these three areas may reflect the degree of
exposure at the TAZ, magnitude of time averaging, and even the local sedimentation
history, relatable to the sequence stratigraphic record. [Fapergs 1982-2551/13-7, CNPq
140568/2014-0 and 140927/2008-5]
the sedimentary dilution of dead remains, it can also enhance the destruction at the
sediment-water interface, by prolonging the residence of fossils in the taphonomically
active zone (TAZ). Shelly (mollusk) concentrations in the marine realm are associated
to stratigraphic discontinuities, which may be bedding planes or unconformities,
allowing suggesting that shifts in the sedimentation style determine the properties of
the skeletal concentration. In the marine setting, shell-beds usually develop in
stratigraphically predictable areas such as sequence boundaries (e.g., downlap
deposits at the base of highstand system tracts, backlap deposits at distal maximum
flooding surfaces, toplap deposits at the top of highstand system tracts, and so on).
The Southern Brazil Shelf (within latitudes 27ºS and 34ºS) is a sediment-starved
passive margin continental shelf, with bioclast concentrations associated to possible
ancient coastlines that might be formed in coordination to wave ravinement surfaces. In
addition, several deposits are also present in areas with no relation to previous sealevel
stabilization areas, where the sediment is mainly constituted by relictual
(~reworked) sand. Fourteen mollusk shell samples from near shelf-break deposits (the
“distal shell-rich” group), eleven mollusk shell samples from proximal, low depth
bioclastic deposits (the “proximal shell-rich” group) and ten samples from sandy
substrate (the “shell-poor” group) were evaluated for taphonomic damage accordingly
to updated taphonomic protocols. This analysis was conducted in order to determine to
which degree de taphonomic properties of recent, developing shelly concentrations in
fact might be related to the position within a sequence stratigraphy framework. Using
multivariate statistical analysis (mainly non-metric multidimensional scalling and
multivariate analysis of variance with permutation) we determined that the three groups
of shell samples in fact are significantly different. The distal deposit is dominated by
low-intensity damage (natural bright and ornamentation); the inverse occurs to the
proximal deposit (samples from the shell-poor area present an intermediate damage
pattern). The taphonomic condition of these three areas may reflect the degree of
exposure at the TAZ, magnitude of time averaging, and even the local sedimentation
history, relatable to the sequence stratigraphic record. [Fapergs 1982-2551/13-7, CNPq
140568/2014-0 and 140927/2008-5]
Research Interests:
An underlying and important question in taphofacies studies is how much the oceanographic and sedimentary conditions do influence the preservation state of fossils. Some actualistic work have shown that the taphonomic profile of death... more
An underlying and important question in taphofacies studies is how much the
oceanographic and sedimentary conditions do influence the preservation state of
fossils. Some actualistic work have shown that the taphonomic profile of death
assemblages are controlled rather by site (or facies) -level factors than large-scale
parameters. Experiments and Recent-based observation performed in small
geographical areas sometimes impair reaching patterns that could be better
transposed to the deep-time record. Here we used samples gathered from a variety of
depths (seven samples from 7 to 150 m) along the Southern Brazilian Continental Shelf
(SBCS), in predominantly muddy facies, to determine whether and how much do depth
influence the taphonomic condition observed in bivalve remains. Standard taphonomic
analysis was performed on identifiable shells and fragments larger than 4 mm, using a
categorical scoring system developed from previous publications. Statistical analysis
was conducted in the free software R, using package vegan. Multivariate statistics,
composed of cluster analysis, multivariate analysis of variance with permutation
(PERMANOVA) and distance-based Redundancy Analysis (RDA), was performed to
obtain the quantitative proportion of influence of depth over the taphonomic damage
observed in seven bottom-level samples (topmost 10-20 cm layer, roughly
corresponding to the Taphonomically Active Zone). By keeping the facies controlled
(only samples from mud) it was possible to attain the damage to the depth variation
among samples. RDA showed that up to 46% of the taphonomic variation observed
relates to the variation in depth, while three groups of taphonomic signatures can be
selected, using PERMANOVA (F= 8.2005, p<0.001): Group R1, consisting of
corrasion, encrustation and dissolution holes; Group R2, consisted of fragmentation,
small pits, color alteration, reduced color, and surface bright; and Group R3, consisted
of bioerosion (including sponge and microendolithic traces), large pits, drilling predation
marks and oxidized color. The direct implication for taphofacies analysis of the fossil
record is that some damage types can be targeted to evaluate with more accuracy the
depth gradients present, at least, in mudstones. [Fapergs 1982-2551/13-7, CNPq
140568/2014-0 and 140927/2008-5]
oceanographic and sedimentary conditions do influence the preservation state of
fossils. Some actualistic work have shown that the taphonomic profile of death
assemblages are controlled rather by site (or facies) -level factors than large-scale
parameters. Experiments and Recent-based observation performed in small
geographical areas sometimes impair reaching patterns that could be better
transposed to the deep-time record. Here we used samples gathered from a variety of
depths (seven samples from 7 to 150 m) along the Southern Brazilian Continental Shelf
(SBCS), in predominantly muddy facies, to determine whether and how much do depth
influence the taphonomic condition observed in bivalve remains. Standard taphonomic
analysis was performed on identifiable shells and fragments larger than 4 mm, using a
categorical scoring system developed from previous publications. Statistical analysis
was conducted in the free software R, using package vegan. Multivariate statistics,
composed of cluster analysis, multivariate analysis of variance with permutation
(PERMANOVA) and distance-based Redundancy Analysis (RDA), was performed to
obtain the quantitative proportion of influence of depth over the taphonomic damage
observed in seven bottom-level samples (topmost 10-20 cm layer, roughly
corresponding to the Taphonomically Active Zone). By keeping the facies controlled
(only samples from mud) it was possible to attain the damage to the depth variation
among samples. RDA showed that up to 46% of the taphonomic variation observed
relates to the variation in depth, while three groups of taphonomic signatures can be
selected, using PERMANOVA (F= 8.2005, p<0.001): Group R1, consisting of
corrasion, encrustation and dissolution holes; Group R2, consisted of fragmentation,
small pits, color alteration, reduced color, and surface bright; and Group R3, consisted
of bioerosion (including sponge and microendolithic traces), large pits, drilling predation
marks and oxidized color. The direct implication for taphofacies analysis of the fossil
record is that some damage types can be targeted to evaluate with more accuracy the
depth gradients present, at least, in mudstones. [Fapergs 1982-2551/13-7, CNPq
140568/2014-0 and 140927/2008-5]
Research Interests:
Os depósitos marinhos apresentam um comportamento tafonômico distinto ao longo de sistemas deposicionais e tratos de sistemas no ambiente marinho. Por exemplo, o registro tafonômico de concentrações conchíferas expressivas formadas no... more
Os depósitos marinhos apresentam um comportamento tafonômico distinto ao longo
de sistemas deposicionais e tratos de sistemas no ambiente marinho. Por exemplo, o
registro tafonômico de concentrações conchíferas expressivas formadas no inicio do
Trato de Sistemas Transgressivo é diferente do registrado no final da transgressão.
Contudo, para os ambientes sedimentares transicionais, como lagunas e estuários, a
interação entre a formação de concentrações conchíferas e seus aspectos
tafonômicos permanece desconhecida. Na costa sul do Brasil, afloram depósitos
conchíferos lagunares e estuarinos ainda poucos explorados sob ponto de vista
tafonômico e cuja gênese está relacionada à evolução dos sistemas laguna-barreira
pleistocênicos e holocênico - que compõem a Planície Costeira do Rio Grande do Sul
(PCRS). Com o intuito de melhor compreender a formação das concentrações
conchíferas em ambientes transicionais e caracterizar os principais danos
tafonômicos, foram coletadas amostras de dois afloramentos na porção sul da PCRS:
na Praia das Maravilhas (S1) e no Arroio Chuí (S2). Ambos estão localizados em
depósitos sedimentares do Sistema Lagunar IV, de idade holocênica, e foram
formados em contexto de afogamento da região (retrogradação da barreira): S1
corresponde a um depósito condensado entre limite de fácies e S2 está igualmente
relacionado ao contexto transgressivo, porém com posicionamento ainda indefinido.
Foram avaliados, pelo mesmo observador, parâmetros como articulação,
fragmentação, danos à margem (inteira e fragmentada), dissolução, alteração de fina
escala, bioerosão e incrustação. Ambos os sítios apresentaram elevado grau de
desarticulação e fragmentação e moderado grau de dissolução. Entretanto, em S2 a
bioerosão e a incrustação foram potencializadas, com diferenças estatísticas em
relação a S1. Além disto, foram realizadas datações AMS 14C, que revelaram que as
amostras provenientes de S1 exibem uma maior amplitude temporal (1000 anos) do
que o observado em S2 (220 anos), o que é o padrão encontrado para depósitos
marinhos. Isto reforça que, embora inseridos em contexto transgressivo, os depósitos
apresentam variação interna considerável referente ao time-averaging, consoante ao
que ocorre nos depósitos marinhos. Além deste viés temporal, ainda pouco explorado,
os parâmetros bioerosão e incrustação mostraram-se viáveis na distinção entre
concentrações conchíferas em depósitos lagunares e estuarinos inseridos em contexto
transgressivo. [FAPERGS 1982-2551/13-7]
de sistemas deposicionais e tratos de sistemas no ambiente marinho. Por exemplo, o
registro tafonômico de concentrações conchíferas expressivas formadas no inicio do
Trato de Sistemas Transgressivo é diferente do registrado no final da transgressão.
Contudo, para os ambientes sedimentares transicionais, como lagunas e estuários, a
interação entre a formação de concentrações conchíferas e seus aspectos
tafonômicos permanece desconhecida. Na costa sul do Brasil, afloram depósitos
conchíferos lagunares e estuarinos ainda poucos explorados sob ponto de vista
tafonômico e cuja gênese está relacionada à evolução dos sistemas laguna-barreira
pleistocênicos e holocênico - que compõem a Planície Costeira do Rio Grande do Sul
(PCRS). Com o intuito de melhor compreender a formação das concentrações
conchíferas em ambientes transicionais e caracterizar os principais danos
tafonômicos, foram coletadas amostras de dois afloramentos na porção sul da PCRS:
na Praia das Maravilhas (S1) e no Arroio Chuí (S2). Ambos estão localizados em
depósitos sedimentares do Sistema Lagunar IV, de idade holocênica, e foram
formados em contexto de afogamento da região (retrogradação da barreira): S1
corresponde a um depósito condensado entre limite de fácies e S2 está igualmente
relacionado ao contexto transgressivo, porém com posicionamento ainda indefinido.
Foram avaliados, pelo mesmo observador, parâmetros como articulação,
fragmentação, danos à margem (inteira e fragmentada), dissolução, alteração de fina
escala, bioerosão e incrustação. Ambos os sítios apresentaram elevado grau de
desarticulação e fragmentação e moderado grau de dissolução. Entretanto, em S2 a
bioerosão e a incrustação foram potencializadas, com diferenças estatísticas em
relação a S1. Além disto, foram realizadas datações AMS 14C, que revelaram que as
amostras provenientes de S1 exibem uma maior amplitude temporal (1000 anos) do
que o observado em S2 (220 anos), o que é o padrão encontrado para depósitos
marinhos. Isto reforça que, embora inseridos em contexto transgressivo, os depósitos
apresentam variação interna considerável referente ao time-averaging, consoante ao
que ocorre nos depósitos marinhos. Além deste viés temporal, ainda pouco explorado,
os parâmetros bioerosão e incrustação mostraram-se viáveis na distinção entre
concentrações conchíferas em depósitos lagunares e estuarinos inseridos em contexto
transgressivo. [FAPERGS 1982-2551/13-7]
Research Interests:
Aztalan is a Late Woodland/ Mississippian (A.D. 1000-1200) archaeological site located on the west bank of the Crawfish River in Jefferson County, Wisconsin. At its occupational height, a palisade with square bastions enclosed and... more
Aztalan is a Late Woodland/ Mississippian (A.D. 1000-1200) archaeological site
located on the west bank of the Crawfish River in Jefferson County, Wisconsin. At its occupational height, a palisade with square bastions enclosed and subdivided nine hectares of the mound-village complex. This included three flat-topped pyramidal mounds at the northwest, northeast and southwest corners, a natural gravel knoll on the southeast corner, a central plaza and domestic structures including houses, hearths, storage pits and midden deposits. Human remains at Aztalan have been found in primarily four known contexts: 1)
primary, in-flesh inhumations, 2) secondary bundle burials 3) charnel structure cremations and 4) scattered, isolated and processed remains in refuse pits, fire pits, along the inner and outer palisade and strewn across the habitation area. Scattered, isolated and processed human remains at Aztalan have been interpreted as the result of cannibalism or secondary processing in mortuary ritual. Intergroup
hostility has also been suggested but never formally investigated. This research uses taphonomic methods to examine perimortem and postmortem modification to the Aztalan human remains as a means to identify what processes have affected the remains and also to characterize the Aztalan skeletal assemblage. Results of the analysis suggest that when the formal and informal burials at Aztalan are compared to each other and interpreted through the cultural and political
milieu present at Aztalan during that time, an interpretation of intergroup hostility is supported.
located on the west bank of the Crawfish River in Jefferson County, Wisconsin. At its occupational height, a palisade with square bastions enclosed and subdivided nine hectares of the mound-village complex. This included three flat-topped pyramidal mounds at the northwest, northeast and southwest corners, a natural gravel knoll on the southeast corner, a central plaza and domestic structures including houses, hearths, storage pits and midden deposits. Human remains at Aztalan have been found in primarily four known contexts: 1)
primary, in-flesh inhumations, 2) secondary bundle burials 3) charnel structure cremations and 4) scattered, isolated and processed remains in refuse pits, fire pits, along the inner and outer palisade and strewn across the habitation area. Scattered, isolated and processed human remains at Aztalan have been interpreted as the result of cannibalism or secondary processing in mortuary ritual. Intergroup
hostility has also been suggested but never formally investigated. This research uses taphonomic methods to examine perimortem and postmortem modification to the Aztalan human remains as a means to identify what processes have affected the remains and also to characterize the Aztalan skeletal assemblage. Results of the analysis suggest that when the formal and informal burials at Aztalan are compared to each other and interpreted through the cultural and political
milieu present at Aztalan during that time, an interpretation of intergroup hostility is supported.
Research Interests: Cannibalism and Taphonomy
Patterns in rare earth element (REE) concentrations are essential instruments to assess geochemical processes in Earth and environmental sciences. Excursions in the “cerium anomaly” are widely used to inform on past redox conditions in... more
Patterns in rare earth element (REE) concentrations are essential instruments to assess geochemical processes in Earth and environmental sciences. Excursions in the “cerium anomaly” are widely used to inform on past redox conditions in sediments. This proxy resources to the specificity of cerium to adopt both the +III and +IV oxidation states, while most rare earths are purely trivalent and share very similar reactivity and transport properties. In practical terms, the level of cerium anomaly is established through elemental point quantification and profiling. All these models rely on a supposed homogeneity of the cerium oxidation state within the samples. However, this has never been demonstrated, whereas the cerium concentration can significantly vary within a sample, as shown for fossils, which would vastly complicate interpretation of REE patterns. Here, we report direct micrometric mapping of Ce speciation through synchrotron X-ray absorption spectroscopy and production of local rare earth patterns in paleontological fossil tissues through X-ray fluorescence mapping. The sensitivity of the approach is demonstrated on well-preserved fishes and crustaceans from the Late Cretaceous (ca. 95 million years (Myr) old). The presence of Ce under the +IV form within the fossil tissues is attributed to slightly oxidative local conditions of burial and agrees well with the limited negative cerium anomaly observed in REE patterns. The [Ce(IV)]/[Ce(tot)] ratio appears remarkably stable at the microscale within each fossil and is similar between fossils from the locality. Speciation maps were obtained from an original combination of synchrotron microbeam X-ray fluorescence, absorption spectroscopy, and diffraction, together with light and electron microscopy. This work also highlights the need for more systematic studies of cerium geochemistry at the microscale in paleontological contexts, in particular across fossil histologies.