Brazilian Shell Mounds Research Articles

Tetrapod biodiversity in sambaquis from southern Brazil.

Fishermen-hunter-gatherers of sambaquis (Brazilian shell mounds) had an intimate affinity with marine-coastal environments, where they exploited a great variety of fish and mollusks that comprise the best documented fauna from sambaquis. However, other groups of animals as mammals, birds, reptiles, and amphibians are also present in these sites, but are relatively less studied. This paper is the first one focused exclusively on the Tetrapoda biodiversity of sambaquis and aimed to identify tetrapods of ten sites from southern Brazil. We present a faunal inventory and data regarding animal capture and environmental exploitation. We identified the specimens anatomically and taxonomically, analyzed them concerning fragmentation, and quantified the data for the number of identified specimens (NISP) and minimum number of individuals (MNI). Despite the high degree of fragmentation of remains, we identified 46 taxa. As expected, most were from marine animals: cetaceans (total NISP = 2,568 and MNI = 27), otariids (total NISP = 248 and MNI = 32), and seabirds (total NISP = 65 and MNI = 23), indicating great relevance of marine tetrapod fauna as a resource for sambaqui builders (79.39% of NISP). We thus document the close bond between fishermen-hunter-gatherers of sambaquis and the marine tetrapods in southern Brazil.

Archaeological and modern whitemouth croaker fish (Micropogonias furnieri) of southeastern Brazil: A geochemical proxy for environmental preference

In this study, laser ablation–inductively coupled plasma–mass spectrometry was used to characterize the growth patterns of otolith of Micropogonias furnieri from southeastern Brazil under the influence of coastal marine upwelling. Archaeological fish sagittae otoliths of M. furnieri recovered from Brazilian shell mounds (5820‒4980 cal BP) were analysed and compared with those of modern specimens. Otolith Sr/Ca analysis indicated that off southeastern Brazil, M. furnieri shifted from freshwater/brackish in archaeological specimens to brackish/marine in modern times. Regular core-to-edge Sr/Ca oscillations suggest that both modern and archaeological M. furnieri are resident estuarine fish that also use the marine waters adjacent to the coastal zone. Based on analyses of a wide range of otolith edge Sr/Ca values measured in archaeological samples, pre-colonial fishing activities in the coastal regions of Guanabara Bay occurred throughout the year. This study reinforces the importance of M. furnieri as a precolonial fishing resource in this area and demonstrates a shift in fishing practices, where smaller fish are targetted within the bay and larger fish are caught beyond the bay. These data may also be indicative of a shift in the life cycle of this species, possibly caused by the overfishing of this important resource and significant increase in human activities in protected coastal waters in modern times.

PRELIMINARY RADIOCARBON DATING RESULTS OF BONE SAMPLES AT THE LAC-UFF, BRAZIL

ABSTRACTCollagen extraction depends on the state of bone preservation, and the acidity of Brazilian soils often prevents the use of this material for radiocarbon dating. When available, however, bone samples constitute very important chronological records for both archaeological sites and natural depositional sites of specific animals. The extraction of collagen was performed using two filters, the first aiming to remove insoluble contaminants, and the second, a vivaspin ultrafilter 30KD to retain large molecular weight materials. The collagen was liofilized and converted to CO2 by combustion in sealed quartz tubes with CuO and Ag. The graphite was produced by zinc reduction in independently sealed Pyrex™ tubes. In order to verify the accuracy of this protocol, we analyzed a modern bone and four previously dated fragments, including those from the Sixth International Radiocarbon Intercomparison (SIRI), and a fragment of human bone from the Amourins site, a Brazilian shellmound. The results for the known age material are in agreement with the expected and the studied sector of Amourins shellmound was dated 4100–3900 years cal BP from a chronological model performed with charcoal dating found in different stratigraphic layers. Samples were dated at the radiocarbon laboratory of Universidade Federal Fluminense (LAC-UFF) in Brazil.

Fishing for “lucky stones”: Symbolic uses of otoliths in Brazilian shell sites

Otoliths are concretions of aragonite located in fish neurocrania, also popularly known as “lucky stones”. These elements are commonly found in Brazilian shell mounds and middens, and have long been regarded as a by-product of food processing and consumption. Zooarchaeologists commonly use them to identify species, estimate age, quantify fish, and to discuss capture methods and seasonality of occupation, among other aspects of fish and human populations. My research at Jabuticabeira II, a cemetery site with large quantities of otoliths closely associated with burials, explores alternative uses of otoliths by past coastal populations that inhabited the southern Brazilian coast. I reviewed ethnographic and historical accounts of the use of otoliths to check distinct uses of these fish elements. I analyzed 9258 otoliths and 76,990 fish bones from Jabuticabeira II to identify patterns of fragmentation, thermal alteration, element representation and distribution across contexts. The results indicate that otoliths were deliberately placed in burials, pointing to the symbolic value of otoliths. This research reinforces the need to consider the non-economic uses of fish by pre-historic populations.

Otolith-Based Chronology of Brazilian Shellmounds

ABSTRACTThe radiocarbon (14C) chronology of hunter-fisher-gatherers’ archaeological settlements along the Brazilian coast is usually based on mollusk shells, charcoal from hearths, and eventually human bones. However, fish otoliths are found in several archaeological contexts and may represent a reliable option as a chronological record. In this work, we compare the 14C dates of whitemouth croakers (Micropogonias furnieri) otoliths with dates obtained from other materials (shell and charcoal), collected from shellmounds on the coast of Rio de Janeiro, with the aim of improving the accuracy in the 14C dating of Brazilian shellmounds, strengthening the comprehension of the native populations’ occupational trends and the coeval palaeoceanographic context. Based on x-ray diffraction results for archaeological otoliths, their geochemical composition indicates minimal diagenesis effect over time even under burial conditions in the studied sites. The comparison between otolith dates and dates obtained from other proxies revealed similar results but with decreased deviations in otolith dates in all of the studied sites.

Weaning process and subadult diets in a monumental Brazilian shellmound

Studies on settlement patterns suggested that the fisher-hunter-gatherers who constructed the shellmounds (or sambaquis) scattered along the Brazilian Southeastern coast must have experienced considerable population growth by living in rich coastal settings. In this paper we assess, using stable isotopes, the weaning patterns and subadult diets of the sambaqui Jabuticabeira II (1214–830 cal BC to 118–413 cal AD) to test: 1) if weaning strategies are compatible with scenarios of high population density and 2) if there are evidences of dietary sex differences and sex-biased parental investment. Stable isotope data (δ15N, δ13Ccol, and δ13Cap) of 106 samples from 60 individuals (adults and subadults) were analyzed by combining bone cross-sectional and tooth serial-sectioning approaches to simulate a longitudinal study. Various analytical methods were used to describe weaning processes by identifying age-related changes in the diet of juveniles compared to those of adults. The isotopic results show that although exclusive breastfeeding length is variable, the introduction of a supplementary diet occurs around 6 months of age, whereas complete weaning was achieved for most children at approximately 2–3 years of age (more probably ~2.3 years of age). Little variability was observed in weaning and post-weaning diets. Differences between adult males and females suggest sex-biased dietary peculiarities. However, no clear cut difference in parental investment strategies favoring boys could be found. Because a weaning completion age of 2.3 years (and the presumed inter-birth interval that corresponds to) can be associated with slow to moderate growth, our reconstruction of weaning patterns and subadult diets of this sambaqui group partially supports a scenario compatible with high population growth.

The Shell Midden Conundrum: Comparative Micromorphology of Shell-Matrix Sites from South America

Shell-matrix sites are one of the most widespread archaeological deposits in the world. They inform archaeologists about human adaptations to coastal environments, the evolution of coastal economies, ritual practices, and prehistoric architecture. In recent years, the micromorphological study of Brazilian shellmounds and a shell midden from Tierra del Fuego revealed unique information about the human behaviors related to the formation of shell-matrix sites. These investigations refined our knowledge concerning the upward sequence of events involved in the growth and post-depositional evolution of the deposits. Micromorphological studies denied the traditional view of shell-matrix sites as simple secondary deposits of food remains, providing evidence of trampling surfaces, midden redeposition, domestic spaces, abandonment episodes, and intra-site differences. Dissimilarities were detected in the pre-depositional history of sediments in the shellmounds and shell middens that also attest to differences in site use and function. This comparative study highlights the role of micromorphology in the study of shell-matrix sites as a unique approach intended to disassemble the sequence of events hidden in the intricate stratigraphies. The technique has the potential to reveal microdepositional events and/or the weathering process of the seemingly thick layers of densely packed shell that characterize shell-matrix sites worldwide.

Brief communication: A re-evaluation of the health index of southern Brazilian shellmound populations.

The southern Brazilian shellmounds provide archaeological evidence of prolonged human activity in the coast from approximately 6000 to 1000 BP. Shellmound building populations exploited the rich coastal estuarine zones, and the human remains recovered from them are important sources of information on health and overall lifestyle of these mid-Holocene groups. Therefore, they were included in the Western Hemisphere Global History of Health project. The shellmounds contribute the highest Health Index in the Western Hemisphere, but these conclusions are based on collections that exclude postcranial remains. Here, we reconstruct the Health Index for one specific shellmound using both cranial and postcranial remains to determine whether the initial studies might misrepresent the relative health of the Brazilian shellmound builders. The Health Index was calculated for a sample of 18 complete skeletons recovered from the shellmound Porto do Rio Vermelho 02 (Santa Catarina Island, Brazil). The Heath Index was calculated with and without postcranial markers and the results are compared with the Western Hemisphere Global History of Health data. The Health Index for Porto do Rio Vermelho 02 is lower than the reported average for American series in the Western Hemisphere Global History of Health Project and considerably lower than the original index reported for Brazilian shellmounds. This discrepancy is due to an increased prevalence of infectious disease and low stature. Although the Health Index remains a useful comparison statistic, re-evaluation of fragmentary skeletal remains demonstrates the need for caution when applying it to incomplete skeletal series.

The bone degenerative processes in senile fishes from Holocene Brazilian shell mounds.

Zooarchaeological collections from shell mounds in Rio de Janeiro (2,470-4,632cal BP) contain a high prevalence of swollen fish bones belonging to the Atlantic spadefish (Chaetodipterus faber), crevalle jack (Caranx hippos) and fat snook (Centropomus parallelus). Given the lack of knowledge of the bone degenerative process in senile fishes, this study analysed hyperostotic bone in zooarchaeological and modern specimens to obtain high-resolution morphology and microstructure reconstruction. We used microCT as well as X-ray diffraction to characterize the crystallographic changes associated with fish senility. Our results showed that trabecular microstructures in hyperostotic bones were consistent with estimated values of the per cent bone volume-to-total volume ratio (BV/TV) and were greater than 60% in cortical bone. Hyperostotic bones indicated a high radiograph density, and X-ray diffractograms showed a decrease in hydroxyapatite [Ca10 (PO4 )6 (OH)2 ] and calcite (CaCO3 ) neocrystallization. These crystalline and density changes revealed an advanced stage of fish senile and indicate the vulnerability of ageing fish populations.

Marília Oliveira Calazans, Bonding together the pasts: the mining of lime in Brazilian shell mounds

This article seeks to understand the links between mining and archaeology in shell mounds of coastal Brazil, vastly used as lime sources since the early colonization. The shell mounds are the most ancient traces of the occupation of the Brazilian coast and many of them are extinct, because of the mining, which converted their shells into the cement of colonial buildings. Between devastation and cooperation, there are connected activities that were revealed by the scientific papers, published in the nineteenth century, and by the history of the public management of those sites through the twentieth century.

Terrestrial Mollusks as Chronological Records in Brazilian Shellmounds

AbstractAmong other zooarchaeological remains, terrestrial snails’ shells from theThaumastusandMegalobulimusgenera are found in some Brazilian shellmounds, presenting a potential substitute for charcoal in radiocarbon dating analyses, as reliable representatives of the atmospheric carbon isotopic ratio. In this paper, we present statistically similar results of both charcoal and land snails samples from the same archaeological contexts in three settlements on the coast of Rio de Janeiro. The Manitiba I shellmound results range from 4.2 to 3.7 ka cal BP (95.4%), contemporary with the Saquarema shellmound, occupied during the period from 4.3 to 3.6 ka cal BP (95.4%). For the Usiminas shellmound, two groups of samples revealed different periods of time for two occupational layers from 2.3 to 2.1 ka cal BP (95.4%) and from 1.6 and 1.3 ka cal BP (95.4%). A model constraining each group of samples to within a single phase has a general agreement of 97% with only two outliers out of 22 dates, yielding minimum individual agreement of 74% and 7% posterior outlier probability for Saquarema shells. These are good examples of sites in which the occupation chronology can be successfully obtained by the radiocarbon dating of land snails.

Investigation of biodegradation in three different sediment cores from a shellmound (sambaqui) of Brazil, using Ascaris lumbricoides eggs as a model

For more than 30years, paleoparasitologists attempted to recover parasite remains from burial sediments and archaeological layers in Brazilian shellmounds. These sites are located along the shoreline of the country especially at the South and Southeastern regions, and for that reason they are exposed to frequent rainfall. Most of the shellmounds were built in coastal plains, associated with waterbodies, under the influence of high tides and/or inundation. Biodegradation is a factor that affects parasite preservation, especially in open archaeological sites. However, this hypothesis has never been tested in sediments from shellmounds. This study aimed to experimentally evaluate the biodegradation of Ascaris lumbricoides eggs and DNA from three intact cores collected from a shellmound. The cores and control sediments were collected from archaeological profiles composed of different materials. Each core received about 1,000,000 recent eggs, and water was poured over twice a week during 45days, simulating the main climate condition of the environment. The water was collected at the end of each core to observe the egg movement through the archaeological layers of the cores. Soil was sampled in different levels: 31 soil samples from the cores and 12 control samples were analyzed by the spontaneous sedimentation technique and 23 soil samples from the cores and all the control samples were analyzed for the DNA of the parasite. Parasitological evidence was only found in the superficial layers and very few eggs were recovered. Bioactivity caused destruction of most of the eggs and DNA. This research also supports the previous hypothesis that taphonomic factors probably are responsible for fewer findings of A. lumbricoides eggs in South American archaeological sites, especially in open environment sites.

The Path towards Endangered Species: Prehistoric Fisheries in Southeastern Brazil.

Brazilian shellmounds are archaeological sites with a high concentration of marine faunal remains. There are more than 2000 sites along the coast of Brazil that range in age from 8,720 to 985 cal BP. Here, we studied the ichthyoarchaeological remains (i.e., cranial/postcranial bones, otoliths, and teeth, among others) at 13 shellmounds on the southern coast of the state of Rio de Janeiro, which are located in coastal landscapes, including a sandy plain with coastal lagoons, rocky islands, islets and rocky bays. We identified patterns of similarity between shellmounds based on fish diversity, the ages of the assemblages, littoral geomorphology and prehistoric fisheries. Our new radiocarbon dating, based on otolith samples, was used for fishery characterization over time. A taxonomical study of the ichthyoarchaeological remains includes a diversity of 97 marine species, representing 37% of all modern species (i.e., 265 spp.) that have been documented along the coast of Rio de Janeiro state. This high fish diversity recovered from the shellmounds is clear evidence of well-developed prehistoric fishery activity that targeted sharks, rays and finfishes in a productive area influenced by coastal marine upwelling. The presence of adult and neonate shark, especially oceanic species, is here interpreted as evidence of prehistoric fisheries capacity for exploitation and possibly overexploitation in nursery areas. Various tools and strategies were used to capture finfish in seasonal fisheries, over rocky reef bottoms and in sandy littoral environments. Massive catches of whitemouth croaker, main target dermersal species of South Atlantic coast, show evidence of a reduction in body size of approximately 28% compared with modern fisheries. Fishery activity involving vulnerable species, especially in nursery areas, could mark the beginning of fish depletion along the southeastern Brazilian coast and the collapse of natural fish populations.

Fish bone diagenesis in southeastern Brazilian shell mounds and its importance for paleoenvironmental studies

Brazilian shell mounds are relicts of prehistoric settlements characterized as distinct features on the sandy coastal plain, sandy bars of coastal lagoons and rocky island. They are composed of shells of edible marine mollusks, fish remains and wildlife bones intermixed with sand. In the coastal lagoon region of the Rio de Janeiro state these shell mounds range in age between 5100 and 1300 cal BP. In this study we analyzed the geochemistry of the bones of the whitemouth croaker that primarily offers insight on the nature of bone diagenesis and its use for radiochronology and as isotope paleo-thermometer. The x-ray diffractograms of bones from the Tarioba shell mound exhibit elevated calcite profiles in contrast to a reduced hydroxyapatite concentration. Two peaks of quartz and the presence of feldspar provide evidence of exogenous materials, e.g., sand or silt particles, infilling hollow spaces within the fish bones. The Beirada and the Ponte do Girau shell mounds are characterized by the highest peaks of apatite relative to calcite, which is clearly different from the result obtained for Tarioba. The Manitiba profile is similar to the Tarioba profile except for calcite peaks that are approximately three times lower than those for Tarioba. At a depth of 25 cm in the Tarioba shell mound, the redox sensitive index of diagenetic alteration reaches its maximum value, suggesting a zone of accumulation in the soil horizon redox condition. The δ18O derived temperatures profile based on mollusks showed a consistent range from 18.1 to 24.1 °C, indicating seasonal events of intense upwelling of the South Atlantic Central Water breaking the mean warm surface conditions of the Brazil Current. Diagenetic imprints of Tarioba shell mound suggest humid burial conditions with the loss of hydroxyapatite and the enrichment of exogenous calcite. Drier depositional environmental conditions are indicated in the Ponte do Girau and the Beirada shell mounds, while intermediary depositional environmental conditions characterize the Manitiba shell mound. In the period represented by the shell mound samples, the sea level exhibited significant oscillations and portions of the inner shelf were exposed, which may have resulted in an anomalous derived temperature records. These results are compatible with events of anomalous temperatures occurring in the sea level during the time span of occupation of these shell mounds.

Experimental Micromorphology on Burnt Shells of Anomalocardia brasiliana (Gmelin 1791) (Bivalvia, Veneridae) and Its Potential for Identification of Combustion Features on Shell‐Matrix Sites

The identification of in situ or reworked hearths in archaeological sediments is currently one of the main topics in archaeological micromorphology. In the case of shell‐matrix sites (shell mounds and middens), the clast‐supported matrix and high porosity can hamper the clear identification of combustion features. Previous experimental approaches were useful to identify in thin section the transformations induced by heating in mollusk shells, which are related to its mineralogy. Since different species of mollusks contain diverse mineralogy (aragonite, calcite, or both), it is expected that each species follows a specific thermal behavior, although similar general trends exist. In this short contribution, a set of valves of the mollusk Anomalocardia brasiliana (Gmelin 1791) (Bivalvia, Veneridae), the most important component of Brazilian shell mounds, was heated in a muffle furnace at temperatures from 200°C to 800°C. Thin sections were made and their description is presented for the identification of burnt shell of A. brasiliana. This information can help to infer the temperature of prehistoric fires and can assist in the identification of in situ versus reworked hearths in shell‐matrix sites.

Prehistoric Maritime Domain and Brazilian Shellmounds

For at least six thousand years, the Brazilian coast has been explored extensively by different fishing communities. This article deals with the fishing-gatherer societies as coastal communities proposing an interface between shell sites archaeology and maritime anthropology.

Microtaphonomy in archaeological sites: The use of soil micromorphology to better understand bone taphonomy in archaeological contexts

In archaeozoological studies, taphonomic analyses have focused largely on identification of chemical and mechanical changes of the bones recovered during excavation. The quantification of bone remains is usually made using the number of remains (NR). One of the major drawbacks in the use of the NR method is that it does not take into account the variability in size of faunal remains, from large bones to microscopic fragments. In archaeological sites where no macroscopic bone is preserved due to adverse physico-chemical conditions (e.g. high pH), micromorphology can be used to detect the presence of bones and other animal remains. In addition, microscopic observations provide information on the pre and post-depositional alteration of faunal remains, and allow for a semi-quantitative assessment of microscopic bone fragments. In this sense, micromorphology can be used in support of archaeo-taphonomic studies, which have traditionally overlooked microscopic animal remains. This paper presents some applications of the use of micromorphology to understand bone taphonomy at different archaeological open-air sites, including: (1) a shell midden from Tierra del Fuego, (2) a Brazilian shell mound (sambaqui), (3) an Iberian Middle Palaeolithic site and (4) a Mesolithic campsite in northern Scotland.

Building Coastal Landscapes: Zooarchaeology and Geoarchaeology of Brazilian Shell Mounds

ABSTRACT Brazilian shell sites are largely considered to have been multifunctional and the location of both sacred and secular activities. This article explores the joint contribution that zooarchaeological and geoarchaeological analysis can bring to understanding the depositional history of shell sites and their functions. This combined approach is applied to the study of two shell mounds that represent important aspects of the diverse array of shell sites found along the southern Brazilian coast. Jabuticabeira II is a monumental shell mound that has shown unquestionable evidence of being used mainly as a cemetery, and Encantada III is a smaller shell deposit whose function is more difficult to define. Research focusing on formation processes at Jabuticabeira II played an important role in developing a better understanding of the mortuary rituals performed at the site. In Encantada III, zooarchaeology and geoarchaeology contribute to a better characterization of its role as a short-term deposit of long-lasting permanence. Both shell sites and their practical and symbolical attributes represent examples of the complex dynamics of the anthropic construction of a landscape.

Sambaquis (shell mounds) of the Brazilian coast

The Brazilian shell mounds called sambaquis have been well known since the 16th century when clergy, travelers, and members of the colonial administration wrote the first narratives of Portuguese America. However, it was only during the second quarter of the 19th century that, under the orders of the Imperial Government, the first scientific expeditions carried out systematic research on these archaeological sites. The sambaquis of Brazil are found in the costal regions of the south and southeast, from the coast of what is today Espírito Santo State to the Rio Grande do Sul State. The oldest dates come from the states Rio de Janeiro and São Paulo, indicating that there was an occupation as far back as the 6th century BC. The sites are to be found in coves, sandy plains dominated by beach-ridges, rocky outcrops, mangrove groves, lagoons, estuaries or large bays. This landscape variability is equally expressed in the material culture and resource exploitation, which are characterized by a variety of adaptive strategies and diversity between the various cultural contexts.

Efficient but destructive: a test of the dental wash technique using secondary electron microscopy

The Boyadjian et al dental wash technique provides, in certain contexts, the only chance to analyze and quantify the use of plants by past populations and is therefore an important milestone for the reconstruction of paleodiet. With this paper we present recent investigations and results upon the influence of this method on teeth. A series of six teeth from a three thousand years old Brazilian shellmound (Jabuticabeira II) was examined before and after dental wash. The main focus was documenting the alteration of the surfaces and microstructures. The status of all teeth were documented using macrophotography, optical light microscopy, and atmospheric Secondary Electron Microscopy (aSEM) prior and after applying the dental wash technique. The comparison of pictures taken before and after dental wash showed the different degrees of variation and damage done to the teeth but, also, provided additional information about microstructures, which have not been visible before. Consequently we suggest that dental wash should only be carried out, if absolutely necessary, after dental pathology, dental morphology and microwear studies have been accomplished.