Oxygen isotope analysis of California mussel shells: seasonality and human sedentism at an 8,200-year-old shell midden on Santa Rosa Island,California

To evaluate coastal settlement and land use strategies among maritime hunter-gatherers, we analyzed oxygen isotope (δ¹⁸O) data from 131 marine carbonate samples from 21 California mussel (Mytilus californianus) shells obtained from a large ～8,200-year-old shell midden (CA-SRI-666) on California’s Santa Rosa Island. Seasonal distributions of the isotopic data were assigned using a paleo-sea surface temperature model created by comparing modern sea surface temperatures (SST) to a fully profiled ～8,200-year-old shell. For 20 additional shells, we used two sampling strategies to compare season-of-harvest inferences and explore whether the Early Holocene site occupants were sedentary. Estimated season-of-harvest differed by 35 % between the two sampling methods, corroborating recent isotope analysis of an 8,800-year-old shell midden on San Miguel Island. Shellfish appear to have been collected year-round at CA-SRI-666 from intertidal or subtidal water temperatures similar to modern SST in the vicinity of eastern Santa Rosa Island. The isotope results are consistent with other evidence from CA-SRI-666 that suggest that the site served as a residential base for relatively sedentary maritime people.     

Boat-based foraging and discontinuous prehistoric red abalone exploitation along the California coast

Temporally and spatially discontinuous pulses of heavy prehistoric exploitation of red abalone (Haliotis rufescens) have been documented along the southern and central California coast. This article examines the very late (post-950 cal BP) appearance of numerous red abalone processing sites on the Monterey Peninsula in central California. We test three prominent explanations offered for the sudden onset of red abalone processing sites: trophic cascades resulting from human predation on sea otters, logistical foraging by inland residents, and changes in sea surface temperature. A trophic cascade appears to have occurred but does not fully explain the nature or timing of the phenomenon in the region.     

External Auditory Exostoses and its Relationship to Prehistoric Abalone Harvesting on Santa Rosa Island,California

Bioarchaeological research among prehistoric Pacific Coast populations has shown that external auditory exostoses (EAE) are found in high frequencies. On California's northern Channel Islands archaeological research has demonstrated that there was an intense exploitation of red abalone (Haliotis rufescens), particularly between ~8000 and 3500 years ago. If the Island Chumash were free‐diving for red abalone in subtidal waters, EAE should be prevalent in prehistoric populations from Santa Rosa Island. We recorded the presence or absence, number, side and severity of EAE growths for 207 adult individuals from three time periods on Santa Rosa Island. Our results show that ~11% of the total population was affected, including 22.5% of males and ~3.4% of females. The incidence among females increases from 0% in the Early period, to 2.6% in the Middle period, and 6.8% in the Late period. Overall these are lower rates than those reported for other Channel Island and Pacific Coast sites. Given the relatively low percentage of Santa Rosa Islanders affected with EAE, red abalones may have been harvested primarily in shallow waters rather than the deeper subtidal zone. Our data suggest that gender differences in food procurement activities existed on Santa Rosa Island throughout prehistory, congruent with the argument that EAE is an activity‐induced pathology that occurs with prolonged exposure to cold water and wind conditions. Copyright © 2015 John Wiley & Sons, Ltd.     

Identifying Shell Middens With Historic Aerial Photos: An Example From California's Santa Cruz Island

Using 1929 aerial photos of western Santa Cruz Island, we identified numerous potential shell midden locations, followed by confirmation of site locations via field reconnaissance. Heavy grazing by sheep, cattle, and pigs closely cropped island vegetation in the early twentieth century, exposing shell middens now often covered with thick vegetation. We discuss the potential and limitations of early aerial photos as aids to archaeological site identification and management in island and coastal settings. Although results varied from island to island, we found historic aerial photos to be extremely useful for documenting previously unrecorded sites on Santa Cruz Island, ranging from historical EuroAmerican sites to Island Chumash sites dating to as much as 7250 cal BP. These methods may also be applicable to other islands around the world subject to heavy livestock grazing in the past, especially where introduced animals have been removed and recovering vegetation now obscures archaeological sites.     

Environmental context of a Neolithic site at Beifudi,north-west Hebei Province,China

The earliest evidence of prehistoric religious practice in China found so far comes from excavations at Beifudi, about 120 km south of Beijing, in the form of votive offerings and porcelain sorcery masks dated to the period 8000–7000 yr BP. These finds are part of a rich Neolithic site located on the second river terrace on the north shore of the Yi River. This paper presents results of pollen analysis of part of a sediment profile from a depression at the edge of first terrace towards second terrace, a few hundred metres away from the main archaeological finds. A sequence of marked changes in environment occurred between 9000 cal yr BP and 6000 cal yr BP, and dating evidence suggests strong associations with the ebb and flow of human activity in the area. The first phase of activity on the site begins at around 8000 cal yr BP, towards the end of a period of relatively dry, cold environmental conditions. Between 7800 cal yr BP and 7400 cal yr BP, the first clear evidence of cereal cultivation appears in the pollen record. Rich archaeological finds occur during the same time period, suggesting local prosperity. This first phase of the Beifudi culture ends at 7300 cal yr BP, when warmer and wetter conditions are inferred and wetland areas expand, reducing the area available for crop cultivation near the site. A return to drier and cooler conditions from 6900 cal yr BP corresponds with the second phase of apparent prosperity in the archaeological record from Beifudi. This phase ends at around 6500 cal yr BP, at the start of another shift towards wetter conditions in the flood plain environment. The pollen record suggests that environmental conditions in the flood plain were a major determinant of human activity at Beifudi in the early-mid Holocene.     

Intensifying collection and size increase of the tessellated nerite snail (Nerita tessellata) at the Coconut Walk site,Nevis, northern Lesser Antilles,AD 890–1440

Recent archaeological investigation at the Coconut Walk site on the Caribbean island of Nevis revealed dense 40 cm deep midden deposits that accumulated between cal AD 890–1440. Analysis of invertebrate faunal remains reveals an assemblage dominated by nerite snails. We measured the length and width of more than 2700 tessellated nerite (Nerita tessellata) shells to investigate evidence for changing mean size that might be indicative of intensifying human predation pressure or other cultural and natural processes. Contrary to similar archaeomalacological studies in which size decline is detected, we observed a statistically significant size increase for N. tessellata over time. This size increase is coupled with increasing levels of tessellated nerite exploitation at the Coconut Walk site. Results suggest that tessellated nerite use was sustainable over several centuries of site occupation. Our findings have important implications for investigations of anthropogenic impacts on prehistoric mollusc populations. In addition, the findings reported here provide important insight into human subsistence patterns during the Late Ceramic Age in the Caribbean and a framework for comparison with observations from other Pre-Columbian sites in the Caribbean.     

Plant microfossils in prehistoric archaeological deposits from Yuku rock shelter,Western Highlands,Papua New Guinea

Plant microfossil analysis was carried out on anthropogenic deposits from Yuku rock shelter, possibly occupied from before 14,200 cal. BP to recent times, in the Papua New Guinea Highlands. Elaeocarpus pollen has extremely high percentages throughout. Starch residues of lesser yam (Dioscorea esculenta) and one or more, undifferentiated Dioscorea species were identified, suggesting processing of these taxa since first use of the site. The latter include Dioscorea alata, Dioscorea bulbifera, Dioscorea nummularia and Dioscorea pentaphylla. Pollen and phytoliths of banana (Musa) appear 5200 cal. BP. We cannot differentiate between naturally growing and cultivated yams and bananas. Putative truffle (hypogeous Ascomycotina) spores in the deposits suggest foraging of truffles.     

Geochemical methods for inferring seasonal occupation of an estuarine shellmound: a case study from San Francisco Bay

Seasonal patterns of Native American residence and use of shell mounds of the San Francisco Bay area, California are of great interest. This work investigates seasonal occupation by means of a new method for interpretation of geochemical data from Mytilus trossulus specimens recovered from one of these structures, the Ellis Landing Shell Mound (CA-CCO-295). The approach, which is suitable for relatively small shell fragments from a variety of archaeological contexts, is used to infer the environmental conditions (temperature and salinity of ambient water) at harvest time, compared with average conditions for the period, and thus estimate the season during which the shells were harvested. This information, in turn, is employed to evaluate current models about the growth and construction of prehistoric shell mounds in San Francisco Bay. The method was applied to seven different lenses in the shell mound ranging in age from ∼240 cal yr BP to ∼3510 cal yr BP. We found that, although seasonal occupation varied over time, it generally was confined to summer through late fall, with little indication of winter gathering. Our findings suggest that California shell mounds, such as Ellis Landing, were constructed in a very different manner than some other mounded places used by contemporaneous hunter-gatherers elsewhere in North America.     

Evidence for introduced taro (Colocasia esculenta) and lesser yam (Dioscorea esculenta) in Lapita-era (c. 3050–2500 cal. yr BP) deposits from Bourewa,southwest Viti Levu Island,Fiji

Starch residue, pollen and phytolith analysis was carried out on coralline deposits from a c. 3050–2500 cal. yr BP Lapita site at Bourewa, Viti Levu, Fiji. Starch grains, calcium oxalate crystals and xylem cells of introduced Colocasia esculenta and Dioscorea esculenta were identified, involving a process of elimination of possible taxa by cross-correlation of microfossil types. The data provide an eastward extension of direct evidence of Lapita horticulture in Remote Oceania previously identified in Vanuatu.     

Human impacts on ancient shellfish: a 10,000 year record from San Miguel Island,California

We use measurements of more than 11,000 marine shells from 41 archaeological components to construct a 10,000 year record of human impacts on ancient mussel and abalone stocks on San Miguel Island, California. General reductions in the mean size of mussel and abalone shells gathered through time are attributed to growing human population and predation pressure. Based on comparison with historically documented changes in shellfish communities caused by the local extinction of sea otters in the 19th century, changes in mean shell size and the abundance of other shellfish species may have been facilitated by Native American predation on sea otters as early as 7500 years ago. Despite having measurable impacts on local ecosystems, Native Americans on San Miguel harvested huge quantities of shellfish throughout the Holocene. Such long-term harvests appear to have been sustained by an early emphasis on fishing at lower trophic levels, by periodically shifting village locations, and by intensifying the use of finfish and sea mammals through time. This pattern of “fishing up the food web” contrasts with many modern fisheries, suggesting that the study of ancient fisheries can help us better manage our own endangered coastal ecosystems.     

The collision of heritage and economy at Uxbenká, Belize

The relationship between the Mopan Maya community of Santa Cruz and the Classic period Maya site of Uxbenká in southern Belize has had a lasting impact on archaeological investigation and conservation at the site over the last generation. Community members, long the ‘stewards’ of Uxbenká, believe they have an economic right to the ruins that translates loosely into ‘ownership’. Although they seek to maintain the relationship between Santa Cruz and Uxbenká, archaeologists with the Uxbenká Archaeological Project (UAP) challenge the legitimacy of the community’s claim via the power vested in them by the state to conduct scholarly investigations at the site. For both the UAP and the state‐affiliated Institute of Archaeology, Uxbenká belongs not to one village but to all Belizeans. This paper is a data‐driven analysis of the interactions and expectations of community members, archaeologists, and the state as they interact within the archaeoscape of Uxbenká.     

A 28,000 year old excavated painted rock from Nawarla Gabarnmang,northern Australia

We report new archaeological excavations from northern Australia revealing part of a charcoal design likely to be c. 28,000 years old (and chrono-stratigraphically constrained within the period 15,600–45,600 cal BP) on a small rock slab fallen from the ceiling at the rockshelter of Nawarla Gabarnmang in Jawoyn country, Arnhem Land. This represents the oldest confirmed pictograph in Australia.     

GPR and inductive electromagnetic surveys applied in three coastal sambaqui (shell mounds) archaeological sites in Santa Catarina state, South Brazil

In this article, GPR – Ground Penetrating Radar and inductive electromagnetic (EM38 equipment) results are presented for three archaeological sites of shell mounds located between Laguna and Jaguaruna cities, mid-southern coast of Santa Catarina state, Brazil. The Jabuticabeira II, Santa Marta IV, and Encantada III sites were studied. These sites consist of carbonate shell mounds built by societies that inhabited this region during the pre-colonial period (7.5–1.3 ky BP). Geophysical responses obtained in these archaeological sites had allowed the identification of anomalous regions related to archaeological point targets as well as continuous targets, correlated to the shell mound's structure and buried geologic features. GPR numerical modelling studies were done in order to evaluate the performance of the GPR method in relation to materials found in that environment, besides helping interpretations of real results. The synthetic GPR model was a good match with real data obtained in the field. So, the real and synthetic results serve as a reference guide to direct excavation activities in these archaeological and geological structures. In the Jabuticabeira II shell mound, lithic materials and burials were found amidst archaeological layers characterized by sediment rich in organic material, ferruginous concretions, and loose shells. In the Santa Marta IV archaeological site, a concentration of ceramic materials, burials and fireplaces were found. In the Encantada III site, a strong anomaly characterized by a hyperbolic reflection was related to the presence of a silicified tree root; a great example of ambiguity in shallow geophysics interpretation in archaeological applications. Results functioned as a guide to archaeological excavations, allowing cost and time reduction as well as contributing to improve the knowledge of these archaeological sites situated in southern Brazil.     

Magnetic Sourcing of Obsidians in Southern South America: Some Successes and Doubts

Sourcing of archaeological obsidians is of great importance in unravelling the cultural, social and economic development of many ancient societies. Use of magnetic properties of obsidian fragments has been reported as a cheap, fast and versatile tool for these purposes. One hundred and seventy-six obsidians from archaeological sites and sources in Argentina and southern Chile were analysed magnetically using the weight-normalized intensity of JNRM (Intensity of Natural Remanent Magnetization), the intensity of JSIRM (Intensity of Saturation of Isothermal Remanent Magnetization) at 0·35 T and the bulk susceptibility. The method allowed identification of at least two different sources for archaeological materials found respectively to the north and south of the Lago Argentino, in SW Santa Cruz province, Argentina. Comparison of values from most samples in south and central Santa Cruz with those from a known source may lead to the interpretation that most of them belong to that source. In contrast, a critical analysis of the resolution of this using a larger than usual number of samples from three well distant obsidian sources in Argentina showed that two of the sources showed an almost complete overlapping of these three parameters, and all displayed a very large dispersion of values. This different result indicates that the magnetic sourcing of obsidians may not always have the resolution previously portrayed, but is applicable in certain localities.     

Early Holocene palaeoseasonality inferred from the stable isotope composition of Unio shells from Çatalhöyük,Turkey

Seasonal δ¹³C and δ¹⁸O data are presented from 14 Unio sub-fossil shells unearthed at the archaeological site of Çatalhöyük in central Turkey, spanning the occupation period ca. 9150–8000 cal years BP. The shells likely lived in the small lakes/wetlands around the site before being gathered and taken to Çatalhöyük. Wet-dry seasonal cycles are clearly apparent in the δ¹⁸O_shell profiles with low winter values reflecting winter precipitation and high δ¹⁸O in the summer resulting from evaporation. The most striking trend in the δ¹⁸O data is the drop in maximum summer δ¹⁸O ca. 8300 years BP, which we infer as indicating lower summer evaporation and hence a reduction in seasonality. Previous palaeoclimate records from the area have suggested cooler and more arid conditions, with reduced precipitation, around this time. While the drop in summer δ¹⁸O values could be due to reduced summer temperatures reducing summer evaporation, but there was little change in winter δ¹⁸O, perhaps suggesting winter growth cessation or reduced influence of winter climate change on δ¹⁸O. This shift in seasonal climate could be linked to solar-forced climate change beginning ca. 8600 years BP, and enhanced by the regional expression of the 8·2k event. Changing water balance over the occupation period is likely an important contributory factor behind observed cultural changes at Çatalhöyük in the Late Neolithic/Early Chalcolithic period. Our results might be considered to support the fission-fusion farming hypothesis as we provide additional evidence for wet winter/early spring conditions during the Early Holocene which likely caused flooding of the Çar?amba Fan. The changing water balance after ca. 8300 years BP (i.e. reduced seasonality and potentially reduced local summer evaporation) is also coincidental with the proposed end of this farming system due to multi-decadal drought.     

Meta-analysis of zooarchaeological data from SW Asia and SE Europe provides insight into the origins and spread of animal husbandry

Identifying spatial and temporal variation in animal exploitation patterns is essential for building our understanding of the transition from hunting to stock-keeping. Quantitative analysis of the published records of over 400,000 animal bones recovered from 114 archaeological sites from SW Asia and SE Europe from c12 ka to c7.5 ka cal BP (thousands of calibrated radiocarbon years before present) demonstrates significant spatiotemporal variability in faunal exploitation patterns. Sites in the Euphrates region show adoption of domestic taxa by c10.5 ka cal BP, although on average these taxa contribute less than 10% to total assemblage size. This rises to a median of about 40% by c9.5 ka cal BP, and then to about 45% of total NISP by c8.5 ka cal BP. By c10.5 ka in the Tigris and Zagros region domesticates contribute less than 5% to faunal assemblages, but then rise to a median of about 20% by c9.5 ka and 40% by c8.4 ka cal BP. In contrast, Levantine sites have low numbers of domestic taxa (<1%) until c8.8 ka cal BP, when the proportion dramatically increases to a median of about 35%. This apparent delayed-adoption pattern also holds true for the southern Levant, which shows, on average, low levels (<1%) of domestic taxa until 8.8 ka cal BP, at which point domesticates contribute a median of about 10% to assemblages. In the northern parts of SW Asia, the mid- to late-10th millennium cal BP is pivotal, as proportions of domestic taxa show a dramatic increase in frequency during this time, and the ‘package’ of domestic sheep, goat, cattle and pig becomes more firmly established. This sets the trend for sites of the 9th millennium and the appearance of Neolithic communities in SE Europe from the 8th millennium cal BP onwards, from which point domestic animals are ubiquitous in faunal assemblages.     

Intensification of shellfish exploitation: evidence of species-specific deviation from traditional expectations

As modern humans grapple with the repercussions of their extensive environmental impacts, archaeologists are increasingly looking toward the past to understand the nature and extent of prehistoric human impact on the environment. Many researchers rely heavily on archaeological correlates of resource intensification as a proxy measures of resource depletion, a profound and often catastrophic human impact. However, the traditional conceptualization of the archaeological correlates of shellfish intensification disregards a large amount of species-specific variation. This paper presents archaeomalacological data from Santa Cruz Island, California. The shell midden deposits CA-SCRI-480 contain a high density of Tivela stultorum (Pismo clam). Statistical analysis of the shellfish assemblage reveals significant variation in both the size and quantity of Pismo clam that people collected through time. This paper investigates this unique patterning with due consideration of the natural ecology and life history of the species and illustrates species-specific deviation from the traditional archaeological correlates of shellfish intensification. Increased collaboration with ecologists and biologists can help refine models of intensification when necessary in order create more sophisticated understanding of prehistoric human–resource interactions.     

Measuring subsistence specialization: Comparing historic and prehistoric abalone middens on San Miguel Island,California

Red abalone middens, common on the Northern Channel Islands during the Middle Holocene, have often been interpreted as relatively specialized foraging camps. To test the degree of subsistence specialization of one such site, we compared faunal data from a 6400-year-old red abalone midden (CA-SMI-557) and an historic “Chinese” black abalone midden (CA-SMI-558) located along the same drainage on San Miguel Island. The historic assemblage, resulting from highly specialized abalone harvest, drying, and export activities, provides a baseline for evaluating the degree of subsistence specialization at the red abalone midden, where a wider range of economic and subsistence activities is represented. We illustrate how detailed comparative study of faunal remains, artifacts, site structure, and archival sources can help elucidate the economic function of both historic and prehistoric sites.     

The cultural landscape near the ancient city of Tharros (central West Sardinia): vegetation changes and human impact

The evolution of the cultural landscape in coastal western Sardinia is investigated by means of pollen analysis in the Mistras Lagoon sediments, near the ancient city of Tharros, with particular attention to changes in evergreen vegetation and the impact of human activity. The pollen diagram, spanning the time interval from 5300 to 1600 cal BP, documents the influence of man, climate, and geomorphic dynamics on the evolution of a semi-open evergreen vegetation landscape and variations in extent of a salt-marsh environment. Anthropogenic indicators and microcharcoals concur in depicting increased land use coinciding with the Nuragic, Phoenician, Punic and Roman dominations. Pollen data, along with archaeobotanical evidence, suggest a prevailing arable farming economy, vocated to Vitis and cereals exploitation, during the Nuragic phase until 2400 cal BP, replaced since then by a prevailing stock rearing economy. Between 2050 and 1600 cal BP, a less intensive human impact on the landscape is profiled, consistently with the archaeologically documented abandonment of the rural villages in favour of a slow urbanization, experienced by the Sinis territory in Imperial times. The pollen record provides new insights into the history of important economic plants in the Mediterranean, such as Vitis, Olea and Quercus suber. The results of the pollen analysis reveal how the records of these taxa are primarily influenced by the cultural development of the Sinis region and secondarily by dynamics involving the natural companion vegetation.     

Oxygen isotopic composition of limpet shells from the Beagle Channel: implications for seasonal studies in shell middens of Tierra del Fuego

Shell middens distributed along the coastal areas of the Beagle Channel (Tierra del Fuego) testify the primary role of marine resources in the successful social dynamic of hunter–gatherer–fisher societies (HGF) in extreme high latitude environmental conditions. Intertidal and subtidal limpet species are frequently identified taxa of these archaeological deposits. We investigated whether shell δ¹⁸O of the limpet species Nacella deaurata is a valuable record of local sea surface temperature (SST) and ambient water δ¹⁸O (δ¹⁸Ow) fluctuations, and in turn can be used to estimate the season of its exploitation by Holocene HGF. Sequential shell δ¹⁸O of modern species track seasonal changes of SST and δ¹⁸Ow. The comparison of shell δ¹⁸O profiles of N. deaurata and Nacella magellanica (a coexisting species) suggests the occurrence of distinct growth rate and physiological adaptations between species. Shell δ¹⁸O of zooarchaeological specimens of N. deaurata from Lanashuaia II suggests that animals were exploited predominantly in winter and that experienced similar environmental conditions of present day at ∼1320 years BP. Results also indicate that N. deaurata is a valuable candidate for studying past seasonal changes in SST and δ¹⁸Ow in this southernmost part of South America.