In the following section, the architectural design and the internal organization of an average mega-structure in Maidanetske will be evaluated. The extent to which the architecture and spatial organization of this building differs from normal houses is then examined by comparison with houses 44 and 59 from Maidanetske [34, 36, 37]. The extent to which the findings made for Maidanetske mega-structure 3 are representative is finally evaluated on the basis of comparisons with mega-structures in magnetic plans and other archaeologically examined buildings.

Investigating a mega-structure: The case of Maidanetske mega-structure 3.

Mega-structure 3 in trench 111 was chosen for excavation because the magnetic plan displayed both highly magnetised and low magnetised sections within a clearly demarcated area. The different parts were hypothetically interpreted as roofed and not-roofed areas for different activities. During the excavation it turned out that the area was used for settlement activities already before the construction of the mega-structure.

In order to determine the absolute chronology, eleven bone-samples were 14C dated by accelerator mass spectroscopy at the Poznan Radiocarbon Laboratory from different stratigraphic contexts of trench 111 (Table 3). Pre-mega-structure activities are dated through the dates Poz-87599–Poz-87605 deriving from pits and a levelling layer below the floor of the mega-structure. The phase of use of mega-structure 3 is represented by two dates from disarticulated bones which were found in-between the wall debris of the mega-structure (Poz-87598, Poz-87610). Post-mega-structure activities are represented by two dates from the layer directly above the wall debris (Poz-87609, Poz-87721).

Overall, the dates fall into a plateau of the calibration curve and the following steep section, covering a long range of about 300 years between 3950 and 3650 BCE. Through application of Bayesian modelling and the use of the function boundary with the assumption of two successive occupation phases and several events, the range of the dates becomes significantly narrowed, roughly into the 38th century BCE (Fig 3 and S1 File). However, the overall probability of this model amounts to only 40% (A model = 33.8) due to widely identical dates from the different phases. Higher overall probabilities of more than 100% can only be obtained through exclusion of the potential (too old) outliers Poz-87605, Poz-87609, and Poz-87610. The dating results imply that mega-structure 3 was constructed during phase 3 of the site chronology suggested by Ohlrau [31]. Consequently, mega-structure3 from Maidanetske was build related to the rapid population increase of the 38th century and abandoned at the beginning of phase 4, related to the starting population decrease.

In the magnetic plan of the Maidanetske settlement, the architectural remains of mega-structure 3 appeared as a northwest-southeast aligned anomaly with a floor size of approximately 190 m2 (dimensions 19 x 10 m) (Fig 4). Trench 111, opened over this anomaly, measured 23 x 15 m and the daub package of mega-structure 3 was encountered buried under a Chernozem 0.5 m thick.

Mega-structure 3 was built in an area in which stratigraphic evidence indicates an earlier settlement phase. To this pre-mega-structure occupation belong the pit 111/1, perhaps the pits 111/2–111/5, and a massive levelling layer with numerous pottery finds (Figs 5 and 6). The pits were probably located in the back area of a northwest-southeast running row of houses whose position can be reconstructed based on remaining buildings in the magnetic plan. As the massive filling of pit 111/1 with daub located directly below the central fireplace of the mega-structure shows, the houses of the earlier phase were obviously burnt down and levelled to prepare the ground for the construction of the mega-structure.

Within the mega-structure, daub was not equally distributed, corresponding with the high and low magnetised areas visible in the magnetic plan (Figs 7 and 8) [46]. In some parts of the exterior walls and in the north-western half of the building, concentrations in quantities of between 10 and 50 kg/m2 were found. In contrast, a particularly low amount of daub in the range of up to 1 kg/m2 was documented in the southern quarter of the structure and the surrounding open space. In consequence, an internal division into northwestern and southeastern parts is clearly apparent.

The mega-structure was outlined by a lightweight outer wall made of clay-covered split wood and log timbers. Due to various post-depositional processes, this construction was preserved in different qualities. Based on analysis of negative imprints and the measurements of the burnt daub cover, the width of the wall is estimated to have been about 15–20 cm thick. As building timber, ash (Fraxinus 75%, n = 44) and oak (Quercus 19%, n = 11) were used whose dimensions generally fall below 10 cm [45]. Taking the wood imprints into account, both narrow sides and parts of the southwestern longitudinal part of the wall were constructed with log timbers, while the other parts of the wall were constructed mainly with split wood (Fig 9).

At the southern ends of the longitudinal walls daub-free areas about 1.4 m wide are interpreted as possible entrances. The southeastern narrow side of the mega-structure was particular massive, indicated by the largest diameters of log timbers. A daub concentration 7 m south of the northwestern narrow end might indicate the remains of an interior wall dividing the mega-structure in two parts. The internal wall probably reached 4 m across the house, but 3.50 m remained daub-free, perhaps as a passageway between the two parts of the structure. A small entrance about 1 m wide might also have existed directly north of the interior wall on the northeastern longitudinal side.

The orientation of the negative imprints in the split-wood suggests the timbers were aligned horizontally in the walls of the southeastern part and vertically in the walls of the northwestern part of the mega-structure. The lack of postholes could indicate a construction with horizontal beams as wall foundations. In the northwestern corner the daub remains with vertically oriented negative imprints might be remains of a gable wall which collapsed into the internal space of the mega-structure. The height of the original external wall can be reconstructed to about 3.5 m. Also daub remains of the internal wall suggest an original height of 3–3.5 m.

Below small-sized and chaff-tempered debris of the walls, remains of a burnt rammed earth floor were found in the entire area of the mega-structure (Fig 7). Since this mostly only poorly burnt and partly only 1 cm thick floor layer was preserved exclusively in those places which were also covered by wall debris, it was particularly badly preserved (due to low firing intensity) in the southeastern part of the structure. The floor under the debris of the exterior walls was in best condition and the floor layer was up to several centimetres thick. At the outer edge of the wall debris, even in the locations with better preservation, the floor layer suddenly stopped. Here, the floor layer was slightly raised upwards where it would have originally met the outer walls if they had been preserved in place. In consequence, it is suggested that all 190 m2 of the mega-structure’s interior were originally covered with a rammed earth floor. The outer edge of this rammed earth floor marked the position of the not preserved exterior walls.

In the northwestern part of the building different installations existed. Within the interior space only few remains of furnishings were recovered. However, spatial concentrations of a specific yellowish kind of daub in the northwestern part of the building might indicate destroyed furnishing elements. In normal dwellings such as house 44 similar material was used for the construction of bins and podiums [37].

An oval area 2.2 x 1.3 m, situated within the mega-structure three to five meters away from the northwestern narrow end along the longitudinal axis, marks a fireplace which was raised above the rest of the floor by several extra layers of tamped and burnt earth (I–J/8–10; Figs 7 and 10). Corresponding installations are a standard element of Tripolye houses [53]. Since they are sometimes decorated, they are frequently interpreted as altars [31, 53]. In the installation of mega-structure 3 from Maidanetske at least three successive screed layers lay one above another and testify to a longer-lasting use of the building. In contrast, no signs of floor renewals were determined in the remaining parts of the mega-structure.

The southeastern part of the mega-structure has a size of 10 x 7 m, measuring from the base of the interior wall, which collapsed probably in a southeastern direction. No archaeological features could be detected. In this respect, the southeastern part of the mega-structure is empty, but artefact distributions describe different activity zones.

Artefact distribution patterns provide information about the depositional processes and activities which took place within the mega-structure 3. In the case of certain artefact categories such as querns, bones, and remains of textile production a distinction can be made between activities performed repeatedly over a longer period of time and actions done just before the abandonment of the mega-structure. On the other hand, due to the probable deliberate burning of the mega-structure usual abandonment processes such as the disposal of foreign waste occurred perhaps not or in lower scale. The find distributions of pottery are most likely determined by both, long and short term depositional processes. The overall low degree of fragmentation seems to indicate that pottery was fragmented during a primary context of use (Fig 11).

Pottery is distributed all over the mega-structure (Fig 11). For example, bowls, which are generally associated with consumption activities, are evenly distributed across the whole interior space of the mega-structure (Figs 11 and 12). Nevertheless, concentrations are visible in the northwestern and the southeastern parts. This might indicate different activity areas whose character might be detectable by functional differences of the involved morphological vessel types:

Half-closed and closed vessels, which probably had storage functions, are concentrated in both already described zones (Figs 11–13). In the northwestern part of the mega-structure they are situated in the northeastern area east of the fire place. In the southeastern part they are concentrated in the southern corner beside the postulated entrance.

Kitchen wares, which are associated with food processing activities, occur frequently in the southeastern part but have an additional distribution focus in the northwestern part of the building, mainly southwest of the fireplace (Figs 11 and 14).

In summary, the patterns of pottery distribution indicate food consumption in all parts of the mega-structure (bowls), food processing southwest of the fire place and along the southern walls of the southeastern part (kitchen ware), and food storage northeast of the fireplace and in the southern corner of the southeastern part. The lower fragmentation rate in the indicated zones supports our view that the named activities primarily took place in these parts of the mega-structure (Fig 11).

Remains of querns are again mainly concentrated in two zones of the mega-structure (Fig 11). Several fragments were found at the northwestern end of the building partly inside and partly outside of the external walls. Another concentration was observed in the central area of the southeastern part of the mega-structure, where the only complete quern was found.

In consequence, the different artefact distribution patterns seem to reflect the already discovered dual distribution pattern of the ceramics. We would particularly like to stress the contrast between the only partly preserved querns in the northwestern part and at least one complete and several fragmented querns in the central southeastern part. This might indicate that cereal processing only took place in the southeastern part of the mega-structure where also slightly more cereal remains were found (Fig 11). We interpret the fragmented querns as secondarily appropriated construction material, as also might hold true for a larger number of quarry stones, a boulder, and two unworked stone slabs (Fig 11). They are distributed in certain accumulations along the external walls and along the central axis of the mega-structure.

The spatial distribution of bones clearly reveals another focused activity area in the northwestern half of the mega-structure (Fig 11). In fact, the detailed bone distribution displays a half-circular density at some distance from the fireplace along the walls. This could indicate that the consumption of meat was restricted to the northwestern part of the mega-structure. Since heavily used areas within buildings are typically kept free from perishable waste, it is reasonable to assume that the bones within the building are from a meal just before the building was abandoned.

Other ground-stone artefacts include a polishing stone and a whetstone; both of which were found in the northwestern end of the building. With these artefacts, further activities are identified as taking place in the northwestern part, i.e. the polishing and the sharpening of tools (Fig 11). The distribution of the few flint artefacts (three pieces of debris and one flake) mirrors perhaps again the two larger activity zones in the northwest and southeast of the structure (Fig 11). This also holds true for remnants of textile production (Fig 11). In one concentration six fragments and one complete loom weight were found in the southern corner of the building. The second concentration consisting of a loom weight fragment and a spindle whorl was found in the western corner. The one fragment (foot and calf) of a large anthropomorphic figurine was deposited outside of the building along its northwestern narrow end and may indicate a certain kind of non-utilitarian practice linked to the northwestern part of the mega-structure.

In consequence, multiple domestic activities could be detected and localised. In the northwestern part of the mega-structure in addition to pyrotechnical activities at the fireplace, short-term storage, food preparation, meat consumption, textile production, and tool sharpening and polishing are identified. In the southeastern part of the mega-structure cereal processing, short-term storage, food preparation, and textile production took place. Food consumption is evident in both parts.

Comparing the architectural remains and the artefact distribution patterns, the ‘dichotomy’ between the northwestern and the southeastern part of the building is evident and crucial for the reconstruction of mega-structure 3 (Fig 15):

The ca. 60 m 2 of the northeastern part were constructed as a more or less closed space with walls up to 3.50 m in height and possible entrances from the outside, and a passageway to the southeastern part of the structure. The fireplace holds a central position within this roofed section. The main activities are linked to the consumption of cattle and pork meat, the sharpening of tools, and storage.

of the northeastern part were constructed as a more or less closed space with walls up to 3.50 m in height and possible entrances from the outside, and a passageway to the southeastern part of the structure. The fireplace holds a central position within this roofed section. The main activities are linked to the consumption of cattle and pork meat, the sharpening of tools, and storage. The ca. 70 m2 of the southeastern part were constructed as an enclosed but unroofed space with lower walls up to 1.5 m in height in which cereal processing, but also food preparation, food consumption, short-term storage, and textile production took place.

In principle, our interpretation focuses on the difference between a roofed building in which meat consumption and pyrotechnic activities took place, and an appended unroofed enclosure in which activities including cereal processing were performed. Probably the spatial distribution of vessels (except bowls) with their concentration along the exterior walls indicates their original alignment. The difference between the roofed and the unroofed part of the mega-structure is reflected in the presence of charred Stipa awns in the southeastern part (Fig 11). Feather-grass is a plant of the steppe and might have entered the archaeological record due to its deliberate collection e.g. for matting [54] or attached to the fur of animals that visited spring-summer grasslands [55–57]. The presence of the tiny, charred, Stipa awns could be due to a taphonomical bias such as percolation from upper layers, but a direct radiocarbon date from another context in Maidanetske revealed to be contemporaneous to the site occupation (3969–3794 cal. BCE) [45].

In consequence, the differences in daub quantities between the northwestern and the southeastern part of the mega-structure have definitely architectural reasons and are not due to different degrees of burning. This interpretation is also supported by significant differences in activities between the two parts of the mega-structure. Whether this building was permanently inhabited or sporadically used will now be explored by comparison with other excavated dwellings.