Species identification of archaeological dung remains: A critical review of potential methods

Abstract

Dung, macroscopically recognisable as such or not, can more commonly be found in archaeological contexts than is perhaps realised. Up to now, identification of dung to the species which produced it is usually either tenuous, or is not possible. However, species identification can be very informative and is necessary before any further studies can be conducted on the dung, for example on health and hygiene in the past and palaeoecology. This study presents a review of potential methods by which species identifications of archaeological dung can be undertaken. Criteria for identification can be divided into three broad categories: morphometric features of the dung; the content of dung and contextual evidence. Overall, the chances of a precise identification are high; however, a combination of different criteria and techniques will often be necessary to establish a secure identification. Moreover, preservation issues may exclude the application of some criteria while several criteria require more research and the expansion of reference collections of recent material. The overall aim is to move towards standardised methods for species identification of archaeological dung.     

Phytolith-rich layers from the Late Bronze and Iron Ages at Tel Dor (Israel): mode of formation and archaeological significance

The presence of many phytolith-rich layers in late Bronze and Iron Age deposits at Tel Dor, Israel, are indicative of specific locations where plants were concentrated. Detailed studies of six of these phytolith-rich layers and associated sediments from Tel Dor show that the phytoliths were derived mainly from wild and domestic grasses. The most common domestic grass was the cereal Triticum aestivum (bread wheat). Three of these layers have a microlaminated microstructure, associated dung spherulites and phosphate nodules; characteristics that all point to the phytolith-rich layers having formed from dung in animal enclosures. In two of the layers, the microlaminated structure is absent while dung spherulites and phosphate nodules are present, suggesting that these too originate from dung that was not deposited in an enclosure. The sixth layer is microlaminated but does not contain spherulites. We thus cannot suggest a parsimonious explanation of its observed properties. Concentrations of burnt phytoliths are present in three locations, implying that dung was either burnt in situ or the ashes from burnt dung were redeposited. The transformation of dung accumulations into phytolith-rich layers involves a loss of organic material and hence a significant reduction in sediment volume, which is clearly apparent in the stratigraphy of some of the locations examined. The volume reduction can be observed in the macrostratigraphy and has important implications with regard to macrostratigraphic interpretation. The presence of abundant phytolith-rich layers on the tell has significant implications for the concept of ‘urbanism’ during these periods.     

Charred remains of grains and seeds from the medieval high-status farm site of Reykholt in western Iceland

Abstract

Iceland was settled, primarily by peoples from Norway and the northern British Isles, in the 9th and 10th centuries. The first settlers brought with them from their homelands an agricultural system based on animal husbandry, of which cereal cultivation was an element and also with inputs from fishing, hunting and gathering of wild plants. There are strong indications that barley was cultivated during the first centuries in some parts of the country and that cultivation was at least attempted in other areas. However, Iceland is near the climatic limits of the barley-growing zone, and it is open to discussion how reliable a food source locally grown barley would have been. This paper discusses a seed assemblage of cultivated barley and archetypical weeds of cereal crops dated to between the 10th and 12th centuries AD obtained during archaeological excavations at the high status farm of Reykholt in western Iceland.     

Variable Ovicaprid Diet and Faecal Spherulite Production at Amara West,Sudan

ABSTRACT

This paper presents the results of integrated geoarchaeological and archaeobotanical analyses of desiccated and charred ovicaprid dung pellets from the New Kingdom pharaonic settlement of Amara West (Sudan). These analyses reveal diagnostic phytolithic evidence for considerable variations in plant diet amongst the site’s ovicaprid population. These data shed light on aspects of ancient animal husbandry practice, the settlement’s subsistence economy and residents’ exploitation of natural resources. We also observe that specific phytolith types correlate with the presence (and quantity) or absence of calcium carbonate faecal spherulites in analysed dung pellets. This evidence, augmented by experimental analysis of analogous modern plant material, suggests that dietary Ca intake is implicated in faecal spherulite crystallization within the ovicaprid digestive system.     

Archaeobotanical inference of Bronze Age land use and land cover in the eastern Mediterranean

Charcoal and charred seeds at five Bronze Age archaeological sites discern ancient land use in the eastern Mediterranean. Seed frequencies of orchard crops, annual cereals and pulses, and wild or weedy plants are used to characterize plant utilization at different archaeological sites on the island of Cyprus, in the Rift Valley of Jordan, and in the Jabbul Plain and along the upper Euphrates River valley in Syria. Seed to charcoal ratios provide proxies to determine the relative usage of dung versus wood for fuel across the ancient Mediterranean landscape. Greater charcoal and lower charred seed values are interpreted to represent a wooded environment, while higher amounts of charred seeds and minimal wood charcoal suggest a much great use of dung as a fuel source. Interestingly, Politiko-Troullia (Cyprus, Cypriot archaeological sites are, by convention, named for the nearest modern village (Politiko), followed by an italicized toponym (Troullia) referring to the plot of land that incorporates the site) has the lowest seed to charcoal ratio, suggesting its residents primarily burned wood and that the landscape surrounding Troullia remained relatively wooded during the Bronze Age. In contrast, villagers at Tell el-Hayyat (Jordan) utilized a mixture of wood and dung, in contrast to Tell Abu en-Ni’aj (Jordan), and especially Umm el-Marra and Tell es-Sweyhat (Syria), where inhabitants relied solely on dung fuel. Comparative analysis and interpretation of seed and charcoal evidence thus illustrates the variety of fuel use strategies necessitated by the dynamic and diverse Bronze Age landscapes of the Eastern Mediterranean.     

The impact of manuring on nitrogen isotope ratios in cereals: archaeological implications for reconstruction of diet and crop management practices

Recent archaeological studies of human diet have used stable nitrogen isotope ratios (δ¹⁵N) from human bone collagen to infer the relative importance of terrestrial plant and animal foods. This approach is based on widely observed enrichment of δ¹⁵N up the food chain, plants having distinctly lower values than the herbivores that consume them. Studies of early farming diets in Britain, Denmark and Germany have tended to detect relatively high δ¹⁵N values (e.g. c. +9‰), interpreted as evidence of a diet largely based on animal products, though archaeobotanical evidence for crop cultivation (e.g. carbonised cereal grain and chaff) is widespread. This paper investigates the impact of manuring on δ¹⁵N values in modern cereals, and of charring on these cereal values. The results from two long-term experiments demonstrate that manuring significantly raises δ¹⁵N in cereal grain and chaff. Depending on manuring levels and frequency, it appears that human diets with a major component of such grain would conventionally be interpreted as indicating a largely animal-based diet or a mixed plant/animal diet. Moreover, preliminary analyses of experimentally charred grain and chaff from manured and unmanured conditions are promising for the extraction of reliable ancient δ¹⁵N values from archaeobotanical cereal remains. The wider implications of these results, and the need for further work, are discussed.     

Dismantling Dung: Delayed Use of Food Resources among Early Holocene Foragers of the Libyan Sahara

At Uan Afuda, and other Early Holocene sites of the Acacus mountains, in the Libyan Sahara, dung layers and plant accumulation are a major, but repeatedly neglected, feature of hunter-gatherer communities. To understand the formation and meaning of such features, a multidimensional analysis has been undertaken, combining micromorphological, palynological, botanical, archaeozoological, and archaeological data. The hypothesis here formulated is twofold: plant accumulations are evidence of anthropic activity aimed at the storage of fodder; and dung layers are related to a forced penning of a ruminant, very likely Barbary sheep (Ammotragus lervia). The exploration of these two features has hinted at the existence of a deep reciprocal relationship, which has been interpreted as the cultural control of wild Barbary sheep, leading to a delayed use of food resources. This behavior may be considered an opportunistic strategy adopted to minimize the effects of lean periods and implicates increasing cultural complexity within Late Acacus Saharan forager societies of the 9th millennium B.P.     

Starch granules,dental calculus and new perspectives on ancient diet

Recent work in various parts of the world has suggested the possibility of ancient starch granules surviving and adhering to archaeological artefacts. Often this information is used to infer aspects of diet. One additional source for recovery of archaeological starch granules is dental calculus. The presence of plant food debris in dental calculus is well known but has not been not widely investigated using archaeological material. The extraction of starch granules from dental calculus represents a direct link to the consumption of starchy food by humans or animals. Using dental calculus also sidesteps many other questions still inherent in using starch granules to reconstruct aspects of ancient diet, such as the effects of diagenesis on their morphology; as the starches are trapped inside a concreted matrix they are less likely to alter over time. We used amylase digestion by a starch-specific enzyme to confirm the material as starch.     

Subsistence practices in an arid environment: a geoarchaeological investigation in an Iron Age site,the Negev Highlands,Israel

The Negev Highlands (southern Israel) is an arid zone characterized by settlement oscillations. One settlement peak occurred in the early Iron Age IIA (late 10th and early 9th centuries BC). The most conspicuous structure in many sites of this period is an oval compound comprised of an internal courtyard surrounded by rooms. Two hypotheses for the function of these oval compounds are that they served as Israelite fortresses which guarded the southern border and routes of the Solomonic kingdom, or that they represent local agro-pastoral groups. In order to gather more information regarding the subsistence practices conducted in these oval compounds, we carried out a small-scale excavation at the site of Atar Haroa. We focused on sediment sampling and used several geoarchaeological, as well as isotopic, techniques in order to identify macroscopic and microscopic remains related to animal husbandry and crop agriculture. The remains identified from the archaeological sediments were compared with modern reference materials collected from abandoned Bedouin camps. The excavation included two half rooms and several test pits in the courtyard of the oval compound, featuring one Iron Age occupation level composed of gray sediments and relatively small amounts of pottery, bones and macro-botanical charred remains. Micromorphological, mineralogical, dung spherulite and isotopic analyses carried out on the gray occupational sediments from the rooms show that they originate from wood ash and dung, both used as fuel. Similar analyses of the gray sediments in the courtyard show that they originate only from degraded livestock dung. Phytolith analyses show that the gray anthropogenic sediments have similar concentrations of phytoliths as in control (yellowish) sediments and in the dung of winter free-grazing desert livestock and lichen-grazing black dwarf Bedouin goats. Phytoliths indicative of cereal crops are completely absent in the archaeological dung remains, indicating that cereal crops were not processed by the site inhabitants. Based on ethnographic and archaeological parallels, and on the presence of grinding stones and absence of sickle blades in the excavated rooms, we infer that the inhabitants at the oval compound at Atar Haroa subsisted on livestock herding and bought or exchanged cereal grains. Our results support the hypothesis that the inhabitants at the oval compound at Atar Haroa were desert-adapted pastoralists, rather than garrisoned soldiers.     

Identifying Threshing Floors in the Archaeological Record: A Test Case at Iron Age Tel Megiddo,Israel

Abstract

The identification of activity areas in archaeological sites is an important part of archaeological research contributing to the reconstruction of past ways of life. The threshing floor is an activity area that relates to subsistence practices in agricultural societies, yet identifying threshing floors in the archaeological record is difficult. We present a geoarchaeological study conducted at an Iron Age layered feature unearthed in 1998 at Tel Megiddo, Israel, in which we tested a previous assumption that it represents the remains of a threshing floor. Using micromorphology, mineralogy, elemental analysis, phytoliths, and dung spherulites, we show that the materials comprising the bulk of the layers in the Megiddo feature include large amounts of wood ash and the inorganic remains of livestock dung. Based on these results, coupled with ethnographic data on threshing floors and observations on the macroscopic traits of the feature under consideration, we conclude that the layered feature at Megiddo does not represent a threshing floor but a single-household trash heap. We suggest that the interpretation of similar features at other archaeological sites as threshing floors be reevaluated.     

Early Animal Management Strategies during the Neolithic of the Konya Plain,Central Anatolia: Integrating Micromorphological and Microfossil Evidence

ABSTRACT

This paper examines the contribution of microscopic multi-proxy approaches to the study of early husbandry practices and animal diet by integrated micromorphological, phytolith, and calcitic dung spherulite analyses of midden deposits at the three neighbouring Neolithic sites of Boncuklu (9th–8th millennium cal BC), P?narba?? (7th millennium cal BC) and Çatalhöyük (8th–6th millennium cal BC) in the Konya Plain, Central Turkey.

The results reveal considerable chronological and contextual variation in human-animal inter-relations in open areas between different communities and sites. At Boncuklu, middens display well-defined areas where phytoliths and substantial accumulations of omnivore faecal matter low in spherulite content have been identified. By contrast, open spaces at the Late Neolithic campsite of P?narba?? comprise large concentrations of herbivore dung material associated with neonatal ovicaprine remains from spring birthing. Here, the deposits represent repeated dung-burning events, and include high concentrations of dung spherulites and phytoliths from wild grasses, and leaves and culms of reeds that, we suggest here, derive from fodder and fuel sources. Late middens at Çatalhöyük are characterised by thick sequences derived from multiple fuel burning events and rich in ashes, charred plants, articulated phytoliths – mainly from the husk of cereals, as well as the leaves and stems of reeds and sedges – and omnivore/ruminant coprolites, the abundance of the latter declining markedly in the latest levels of occupation.

The application of this integrated microscopic approach to open areas has contributed to unravelling the complexity of formation processes at these sites, providing new insights into herding practices, diet, and the ecological diversity of Neolithic communities in Central Anatolia.     

Flotation versus dry sieving archaeobotanical remains: A case history from the Middle Horizon southern coast of Peru

Abstract

During excavations at the site of Casa Vieja located in the Peruvian coastal desert, archaeological plant remains were systematically collected to assess whether it is more productive and informative to sieve sandy sediments in dry environments or to process such samples by water flotation, a persistent methodological concern. At Casa Vieja, dual subsamples were collected and analyzed using both of these procedures. For dry, sandy sediment conditions, each processing strategy was found to yield a different view of the botanical remains. Dry sieving recovers more of the larger plant specimens whereas water flotation yields more of the smaller-sized material. These results should be incorporated into archaeological research designs in the future, especially for desert environments.     

Plant macroremains from the Roman harbour of Pisa (Italy)

Abstract

Results relating to the identification of macroscopic plant remains (leaves, fruits, seeds) discovered during the archaeological excavation of the Roman harbour of Pisa, in Tuscany, Italy are reported. The plant samples include the cultivated species Prunus spp., Corylus, Olea, Vicia, Juglans and the nemoral wild species Salix spp., Quercus spp., Fagus, Ulmus, Alnus. The remains of cultivated plants — fragments of fruits and seeds — were perhaps part of the boats' cargo or stores for the crew's meals. In the case of the wild taxa, the simultaneous presence of fruit and leaves, suggests that the remains recovered came from the forest vegetation bordering the area of excavation and the adjacent higher grounds, thus delineating a new vegetation landscape for the ager pisanus.     

An Ethnoarchaeological Case Study of Dung Fungal Spore and Faecal Spherulite Taphonomy in a Pastoral Cave Deposit

ABSTRACT

In alkaline cave sediments, the presence of faecal spherulites is regarded as a reliable indicator of animal dung. Spores of coprophilous fungi are nowadays frequently employed as grazing indicators in palaeoecological sequences, but their use in dryland pastoral deposits is not routine in geoarchaeological practice. The paper assesses the relationship between the occurrence of spherulites and dung fungal spores from an abandoned rock shelter used as a stable for several decades. A clear match between these proxies is shown, and their distribution across the sediments is discussed, highlighting the potential of coprophilous spore analysis from archaeological stabling deposits, alongside other established dung indicators. The abundance of other microfossils (parasite eggs, coccolith plates and freshwater indicators) is also quantified and discussed.     

Vegetation,land, and wood use at the sites of Bat and Al‐Khashbah in Oman (fourth–third millennium BC)

About 4200 charcoal fragments have been identified from the fourth‐ to third‐millennium BC archaeological sites of Bat and Al‐Khashbah in order to gain an understanding of plant resources available at the sites. Acacia sp., Ziziphus sp., and Tamarix sp. were the main taxa identified at both sites and indicate a similar vegetation composition as today. Phoenix sp. (date palm) charcoal also has been found at both sites. Whereas the cultivation of date palm for the 2700–2300 BC layers from Bat was likely, given other circumstantial evidence (i.e. local cereal cultivation and floodwater irrigation), it is unclear whether date palm was cultivated at Al‐Khashbah. Especially for the older periods (3300–2700 BC) it is possible that nomadic pastoralists were exploiting and/or managing wild date palms. The find of Avicennia marina at Al‐Khashbah indicates long‐distance contacts with the coast.     

Wild Birds of the Italian Middle Ages: Diet,Environment and Society

ABSTRACT

Wild birds are intrinsically associated with our perception of the Middle Ages. They often feature in heraldic designs, paintings, and books of hours; few human activities typify the medieval period better than falconry. Prominent in medieval iconography, wild birds feature less frequently in written sources (as they were rarely the subject of trade transactions or legal documents) but they can be abundant in archaeological sites. In this paper we highlight the nature of wild bird exploitation in Italian medieval societies, ranging from their role as food items to their status and symbolic importance. A survey of 13 Italian medieval sites corresponding to 19 ‘period sites’, dated from the fifth to the fifteenth centuries, reveals the occurrence of more than 100 species (certainly an under-estimate of the actual number). Anseriformes and Columbiformes played a prominent role in the mid- and late medieval Italian diet, though Passeriformes and wild Galliformes were also important. In the late Middle Ages, there is an increase in species diversity and in the role of hunting as an important marker of social status.     

The utility of livestock dung for reconstructing recent ethnological and environmental histories

Animal dung is evaluated here as a tool to reconstruct recent societal and environmental changes. Studies completed on the macro- and micro-contents from dung deposited in a mountain cave in Catalonia during the 1970–1980s, preceding the socio-economic changes in the area, was supplemented by the testimony of the last shepherd alive in the area. This information was also compared with evidence from aerial photographs of the area surrounding the cave taken in 1956 and 2009. Although taphonomic distortion of the dung shape precluded its assignment to its producers based on morphology, information from the organic remains reflects the agro-pastoral activities in the mountainous area of the Catalan coast. A lack of calcium phosphate and abundant phytolith and epidermal remains from wild species indicates that the dung was excreted by ovicaprines, who sheltered in the cave during spells of adverse weather. These indicators also signify that the animals fed only on natural vegetation. Insect remains in the dung include fragments of chafers, dung and ground beetles, bees and ants, and whilst the latter may have foraged in the cave, the others may have been accidentally ingested by herbivores. The nannofossils and diatoms found in the dung derive from tertiary crops 4 km away from the cave but within the range of the ovicaprine herd. The lack of cereal and vegetable remains in the dung is consistent with the ethnographic record that shepherds and farmers could not afford to supplement the herds’ diet with fodder crops or grain, a consequence of the low productivity of the local subsistence agriculture. This study further discusses the socio-economic impacts of the introduction of intensive farming, industrialisation and tourism in Catalonia during the latter part of the last century and how they are represented in the dung.     

Plants as material culture in the Near Eastern Neolithic: Perspectives from the silica skeleton artifactual remains at Çatalhöyük

Investigating plants used for building and craft activities is important for understanding how environments surrounding archaeological settlements were exploited, as well as for considering the social practices involved in the creation and use of plant objects. Evidence for such plant uses has been observed at many Near Eastern Neolithic sites but not widely discussed. Survival may occur in a number of ways, including as impressions in clay, and as charred or desiccated macroremains. Another, less well-known, way in which plant artifacts can be found is as silica skeletons (phytoliths). Formed by the in situ decay of plants, their analysis may tell us about taxa exploited, and locations in which plant artifacts were used or discarded. At Çatalhöyük, an abundance of silicified traces of plants used in building materials and for craft activities survive, and are found in domestic and burial contexts. Their analysis demonstrates the routine use of wild plants, especially from wetland areas, for basketry (mats, baskets and cordage) and construction, as well as the secondary use of cereal husk chaff in certain types of building materials. The numerous finds suggest that plant-based containers played an important role as an artifactual class, even after the adoption of early pottery.     

Storage in traditional farming communities of the western Mediterranean: Ethnographic,historical and archaeological data

Abstract

This paper presents ethnographic, historic and archaeological data from the western Mediterranean in order to explore the variability of storage methods and the various strategies that may have existed in the past in this region. The paper includes ethnographic information on traditional storage methods collected in farming communities in northern Morocco (Rif area). We record the use of plant fibres such as canes (Arundo donax), dwarf palm (Chamaerops humilis), esparto grass (Stipa tenacissima) and dis (Ampelodesmos mauritanica) to make containers. Recipients made of cow dung and unfired clay, as well as underground silos, have been also used in this region to store food. In addition, we explore historical and ethnohistorical data on the use of large storage structures, including the study of communal granaries, a particular type of granary located at inaccessible places, such as cliff faces or mountain tops, or within fortified buildings, from which harvests can be easily protected and defended. We also examine the archaeological evidence of storage strategies in the Iberian Peninsula during prehistoric times. The paper informs of the large variety of systems and materials used, the functioning of storage structures, and more generally, provides a framework for reflecting on the enormous diversity of solutions that could have existed in the past and that may have left little or none archeological traces.     

Determining the preservation rating of submerged archaeology in the post-glacial southern North Sea: a first-order geomorphological approach

Abstract

During most of the last glaciation, the southern North Sea floor was exposed and accessible to humans. Archaeological finds are concentrated around Brown Bank, Dogger Bank and the Norfolk Banks, but the Palaeolithic and Mesolithic archaeological potential of these areas is poorly known. Management of submerged archaeological heritage requires knowledge about location (potential) and context, ascribing significance (value) and determining risk. Thus, the preservation potential of primary and secondary archaeological material around these three areas is considered a) in the context of the post-glacial evolution of the southern North Sea and b) regarding natural and anthropogenic processes. A detailed review is followed by original research material describing an approach to assessing preservation potential. In general, low-energy deposits associated with former intertidal, floodplain or lacustrine environments are likely to preserve primary archaeological material, including organic remains, whilst (high-energy) riverine environments are more likely to preserve inorganic secondary archaeological material. The main possible anthropogenic impacts on submerged archaeology result from beam trawling, which may disturb deposits at the seafloor, and aggregate dredging, which may remove secondary deposits. Trawling and aggregate dredging are increasingly contributing to knowledge, through reporting finds through established protocols, and through assisting in funding relevant to multi-disciplinary research.