Chewing coca in South America began by at least 8000 cal BP: our authors found and identified coca leaves of that date in house floors in the Nanchoc Valley, Peru. There were also pieces of calcite — which is used by chewers to bring out the alkaloids from the leaves. Excavation and chemical analysis at a group of neighbouring sites suggests that specialists were beginning to extract and supply lime or calcite, and by association coca, as a community activity at about the same time as systematic farming was taking off in the region.

The authors find a context for the rock art of the central Sahara by excavating and recording examples of engraved stones from circular platforms used to sacrifice animals. The type of rock art known as the Pastoral style, featuring evocative outline drawings of cattle, appears on upright stones incorporated into the platforms in the period 5430–5150 BP, and probably earlier. Furthermore, they show that these places were part of a dense and extensive monumental landscape, occupying a harsh environment, supplying quartzite, but with little settlement, appearing to serve the spiritual needs of hundreds of Neolithic people.

Archaeological investigations of ‘desert kites’ in south Israel show them to have been animal traps of considerable sophistication and capacity, constructed in the Early Bronze Age or earlier. Extensive stone-wall arms gather in gazelles from their habitual trails and canalise them into a sunken enclosure, cunningly hidden from view of the galloping herd until it was too late…

Before 3000 BC, societies of western Asia were cultivating wheat and societies of China were cultivating broomcorn millet; these are early nodes of the world's agriculture. The authors are searching for early cereals in the vast lands that separate the two, and report a breakthrough at Begash in south-east Kazakhstan. Here, high precision recovery and dating have revealed the presence of both wheat and millet in the later third millennium BC. Moreover the context, a cremation burial, raises the suggestion that these grains might signal a ritual rather than a subsistence commodity.

History, legend and memory have long pointed to Co Loa, an earthwork enclosure outside Hanoi, as the seat of an indigenous power that gave identity to the people of the Bac Bo region, north Vietnam. Survey, excavation and a set of radiocarbon dates now put this site on the historical map. The main rampart of the middle circuit was built in the later centuries BC, before the coming of Han Imperial China. Nor was this rampart the first defence. The authors show the potential of archaeology for revealing the creation and development of a polity among the prosperous people of the Dongson culture.

We present the authentication and analysis of these beautiful Dacian bracelets of the first century BC, originally pillaged by treasure hunters and recovered thanks to an international crime chase. They were originally fashioned from gold panned from the rivers or dug from the mines of Transylvania and hammered into the form of coiled snakes. The lack of context is the greatest loss, but a votive purpose is likely given their proximity to the great sacred centre at Sarmizegetusa Regia.

Indian Rouletted Ware pottery is the iconic marker of the overseas reach of the subcontinent at the turn of the first millennium AD. In the mid twentieth century this was naturally seen as prompted by the contemporary Roman Empire, while the later post-colonial discourse has emphasised the independence and long life of Indian initiatives. In this new analysis the author demonstrates a more complex socio-economic situation. While Greyware is distributed long term over south India, Rouletted ware is made in at least two regional centres for coastal communities using a new ceramic language, one appropriate to an emerging international merchant class.

Playing mancala-type games was an addictive pastime of antiquity and leaves its archaeological imprint on steps and ledges in the form of rows of little scoops. Here the author examines the traces of the game at Palmyra and shows that the Roman game of the third century (with five holes a side) was superseded when Palmyra's Temple of Baal was refashioned as a fort in the seventh century or later. The new Syrian game, with seven holes a side, was played obsessively by the soldiers of an Arab or Ottoman garrison on the steps and precinct wall of the old temple.

The chance discovery of a carved symbol on a waterlogged tree of the six–ninth century AD may be the earliest mark on a living tree that has so far come to light. Given its rarity, an obvious interpretation remains elusive, but the authors review a wide range of possibilities from analogies ancient and modern. Symbols on trees have been used to mark trails, the ownership of land and resources, and all manner of votive moments from superstitious sign-making, worship of a god, thanks for a successful hunt or the memory of a loving tryst.

Timbuktu, an iconic destination for medieval caravans crossing the Sahara, has a prehistoric phase, here before AD 1000, which shows varying urban traits. The author's new project examines the context of Timbuktu's prehistoric urbanism by mapping the settlement patterns in its hinterland, and seeks to understand the social impacts of the Sahara's changing climate.

The authors explore the practice of extracting the thighbone from burials in Mesoamerica, making use of a newly excavated Classic period Zapotec burial at the Mitla Fortress, where the femur had been carefully removed and the interment resealed. They conclude that the femur acted as an ancestral emblem and could be used by families of relatively low social rank. This function contrasts with the Aztec, where the large bones could also be used as war trophies. Archaeological readers studying ancestor worship and the cult of relics in other continents will find much of value here.

The excavation of 81 skeletons at Cerro Cerrillos provided the occasion for a rigorously scientific deconstruction of human sacrifice, its changing methods and its social meaning among the Muchik peoples of ancient Peru. This paper shows how bioarchaeology and field investigation together can rediscover the root and purpose of this disturbingly prevalent prehistoric practice. Be warned: the authors' clinical and unexpurgated accounts of Andean responses to the spirit world are not for the fainthearted.

Round and rectangular buildings with grain silos at a Copper Age site in Israel suggested social stratification to the excavators. Using micromorphology, the author demonstrates that while the rectangular building was occupied by people, the round ones had contained animals, perhaps as providers of milk, and dung for fuel. While this removes the direct indication of social variance, it strengthens the argument that animals, as well as grain, formed the basis for the creation of surplus.

The rock-cut churches of Ethiopia have long intrigued visitors and historians – and have frustrated archaeologists seeking their sequence of construction. Do they belong to one grand ceremonial monastic plan, or a long-lived ritual centre, continually refashioned over time? Since the churches are cut into live rock, the conventional signals of archaeological phasing are hard to find. The authors address these problems at the famous site of Lalibela, showing that, embedded in the cuts and openings, the spoil heaps, and even in the now vanished sediments, the stratigraphic sequence is there to be read.

Many thousands of metal objects are retrieved from arable fields every year, by casual discovery or by treasure-seekers with metal-detectors. What is the status of this material? Here a senior archaeologist and a metal-detectorist get together to demonstrate scientifically the hostile context of the ploughsoil and the accelerating damage it is inflicting on the ancient material it contains. Their work raises some important questions about the ‘archive under the plough’: is it safer to leave the objects there, or to take advantage of a widespread hobby to locate and retrieve them?

Peter Mitchell (2008) has recently suggested in this journal that the world is facing a ‘catastrophe’ due to anthropogenic climate warming. Mitchell divides his commentary into two parts, and asks two key questions: what is the role of the archaeological community and individual archaeologists in this impending catastrophe and, how will this affect our day-to-day practice? I support most points in the second part (see Rowland 2008) but offer some alternative perspectives to issues raised in the first section of Mitchell's paper. There is a multiplicity of dimensions to the debate about ‘global warming’ (also referred to as ‘enhanced greenhouse warming’, ‘human-induced climate change’ or ‘anthropogenic warming’), including the socio-political milieu, the climate science itself and resulting government policies and guidelines. Archaeologists/anthropologists have a role to play in each of these areas; in particular the longue durée of the archaeological record can provide some fresh insights, a point on which bothMitchell and I agree. Where I differ fromMitchell is that I see a need to refocus the debate toward issues of sustainability and away from the current over-emphasis on global warming.

Should a public archaeology exhibition focus on objects as objects, or should it also explain something of where they come from and processes of interpreting them? If background is necessary, then how much is needed to make sense of the exhibits? Two recent exhibitions offered different answers. The first was largely descriptive, the second theoretical, and specifically, ‘post-processualist’. Both featured prehistoric anthropomorphic figurines of fired clay. Whether or not because ‘themore human, the less intelligible’ (Hawkes 1954: 162), figurines are among the most intriguing and enigmatic finds. What were they for, and what did they mean? Why do they captivate us today; and how should archaeologists cater for that interest?

Thirty years after Childe's death we reviewed his persisting relevance (Gathercole 1987). Twenty-two more years have since passed, and we are pleased to see that his achievements have been reviewed again – in a special monograph (Saville 2009). Here Peter Gathercole admires the continuing modernity and ethical strength of his mentor's ideas, seasoning his reflections with some personal memories. Readers are invited to send us their own memories and tributes of Peter himself, who died on 11 October 2010 and will be much missed.