The exceptional finding of Locus 2 at Dehesilla Cave and the Middle Neolithic ritual funerary practices of the Iberian Peninsula

RESEARCH ARTICLE The exceptional finding of Locus 2 at Dehesilla Cave and the Middle Neolithic ritual funerary practices of the Iberian Peninsula Daniel Garcı ´a-RiveroID 1 *, Ruth Taylor 1 , Cla ´udia Umbelino 2 , T. Douglas Price 3 , Esteban Garcı ´aViñasID 4 , Eloı ´sa Berna ´ldez-Sa ´nchez 4 , Guillem Pe ´rez-Jordà 5 , Leonor Peña-Chocarro 5 , Marı ´a Barrera-Cruz 1 , Juan F. Gibaja-Bao 6 , Manuel J. Dı ´azRodrı ´guez 1 , Patricia MonteiroID 7 , Juan C. Vera-Rodrı ´guez 8 , Javier Pe ´rez-Gonza ´lez 9 1Departamento de Prehistoria y Arqueologı ´a, Universidad de Sevilla, Seville, Spain, 2Research Centre for Anthropology and Health, Department of Life Sciences, Universidade de Coimbra, Coimbra, Portugal, 3Department of Anthropology, University of Wisconsin-Madison, Madison, WI, United States of America, 4Instituto Andaluz de Patrimonio Histo ´rico, Junta de Andalucı ´a, Seville, Spain, 5Centro de Ciencias Humanas y Sociales, CSIC, Madrid, Spain, 6Institucio ´n Milày Fontanals, CSIC, Barcelona, Spain, 7Interdisciplinary Center for Archaeology and Evolution of Human Behavior, Universidade do Algarve, Faro, Portugal, 8Departamento de Historia I, Universidad de Huelva, Huelva, Spain, 9Wellrounded 360º, Nerja, Spain *[email protected] Abstract There is a significant number of funerary contexts for the Early Neolithic in the Iberian Peninsula, and the body of information is much larger for the Late Neolithic. In contrast, the archaeological information available for the period in between (ca. 4800-4400/4200 cal BC) is scarce. This period, generally called Middle Neolithic, is the least well-known of the peninsular Neolithic sequence, and at present there is no specific synthesis on this topic at the peninsular scale. In 2017, an exceptional funerary context was discovered at Dehesilla Cave (Sierra de Ca ´diz, Southern Iberian Peninsula), providing radiocarbon dates which place it at the beginning of this little-known Middle Neolithic period, specifically between ca. 4800–4550 cal BC. Locus 2 is a deposition constituted by two adult human skulls and the skeleton of a very young sheep/goat, associated with stone structures and a hearth, and a number of pots, stone and bone tools and charred plant remains. The objectives of this paper are, firstly, to present the new archaeological context documented at Dehesilla Cave, supported by a wide range of data provided by interdisciplinary methods. The dataset is diverse in nature: stratigraphic, osteological, isotopic, zoological, artifactual, botanical and radiocarbon results are presented together. Secondly, to place this finding within the general context of the contemporaneous sites known in the Iberian Peninsula through a systematic review of the available evidence. This enables not only the formulation of explanations of the singular new context, but also to infer the possible ritual funerary behaviours and practices in the 5 th millennium cal BC in the Iberian Peninsula. PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 1 / 46 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Garcı ´a-Rivero D, Taylor R, Umbelino C, Price TD, Garcı ´aViñas E, Berna ´ldez-Sa ´nchez E, et al. (2020) The exceptional finding of Locus 2 at Dehesilla Cave and the Middle Neolithic ritual funerary practices of the Iberian Peninsula. PLoS ONE 15(8): e0236961. https://doi.org/10.1371/ journal.pone.0236961 Editor: Peter F. Biehl, University at Buffalo - The State University of New York, UNITED STATES Received: March 25, 2020 Accepted: July 16, 2020 Published: August 13, 2020 Copyright: ©2020 Garcı ´a-Rivero et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the manuscript. Funding: This research was carried out within the project "High-resolution chronology and cultural evolution in the South of the Iberian Peninsula (circa 7000-4000 cal BC): a multiscalar approach" (PGC2018-096943-A-C22), funded by: FEDER/ Spanish Ministry of Science and Innovation - State Research Agency. The archaeological field season carried out during 2017 at Cueva de la Dehesilla 1. Introduction and objectives Neolithic funerary practices in the Iberian Peninsula are relatively well known. In the current century, this field has been the object of several regional analyses at different scales [e.g. 1–9], and some supra-regional syntheses [10,11]. However, the present state of knowledge is unevenly distributed between the different archaeological periods that make up the general framework of the Neolithic. Currently, there is a large number of sites attributed to the Early Neolithic [12], conventionally dated in the Iberian Peninsula between ca. 5600–4800 cal BC. At the least, 30 sites display some kind of funerary contexts. The funerary evidence known at present for this period is most abundantly from cave sites. Disarticulated or isolated human bones are often found with other artifactual and faunal remains, probably partly due to postdepositional processes. Inhumations are generally individual, although several burials may coexist in the same rooms or common areas of the cavities. There are some cases of secondary burials and rare multiple burials. At the same time, burials are documented at open-air sites, where they tend to belong to individual and very rarely multiple inhumations deposited in pits within settlement contexts. Generally, the bodies are placed in a flexed position, lying on the side, with variable assemblages of grave goods, essentially combinations of pottery, stone tools, bone and/or shell elements, and frequently faunal remains [11]. The body of information available for the funerary practices of the Late Neolithic is much larger. However, the chronological definition of this period in calendar years is more complex, due to the greater degree of regional variation displayed by the archaeological record. In some areas, the onset of the Late Neolithic is attributed to the end of the 5 th millenium cal BC, but only becomes generalised throughout the Iberian Peninsula during the course of the 4 th millennium cal BC. During this period, burials inside caves are still documented, although funerary practices mostly take place in the open, in graves for individual or multiple burials within settlement areas or, more commonly, in areas designated as burial grounds. The types of funerary structures are diverse. There are several documented open-air necropoli (inhumations in graves), and artificial caves used as burial chambers. The monumental nature of some of the earth and stone burial structures is a distinguishing trait of the Late Neolithic, and the emergence of megalithism is generally linked to this period [11,13, but see 14,15]. In contrast, the available archaeological information, especially funerary data, is notably scarcer for the time-span between these two periods. The lower threshold is problematic, this period may be placed approximately between 4800-4400/4200 cal BC. The scarcity and great diversity of the archaeological record at this time has generated a great deal of controversy in the artifactual characterisation, the typological synthesis, and the periodisation of the central part of the 5 th millennium cal BC [see for example, 16]. Undoubtedly, this period, generally called Middle Neolithic, is the least well-known of the Neolithic sequence of the Iberian Peninsula, especially with regards to the funerary record that occupies us here, and there is presently no specific synthesis on this subject at the peninsular scale. In 2017, during the archaeological excavations at Dehesilla Cave (Sierra de Ca ´diz), a depositional context was discovered, providing radiocarbon dates placing it at the beginning of the little-known Middle Neolithic period, specifically between ca. 4800–4550 cal BC. The find is an exceptional ritual funerary deposition (Locus 2) constituted by two adult human skulls and the skeleton of a very young sheep/goat, associated with a stone structure and a hearth, and a number of pots, stone and bone tools and charred plant remains. The finding takes on particular importance, not only because of its singular characteristics but also, considering the background briefly presented above, because it offers a unique opportunity to advance our knowledge about the funerary and ritual practices of the populations of the elusive central span of the 5 th millennium cal BC in the Iberian Peninsula. PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 2 / 46 received financial support from several entities and funding programs at the University of Seville (VI Plan Propio de Investigacio ´n y Transferencia, III Plan Propio de Docencia, Facultad de Geografı ´a e Historia and Dpto. de Prehistoria y Arqueologı ´a), as well as from the Research Centre for Anthropology and Health, University of Coimbra. GPJ’s work was supported by the postdoctoral contract IJCI-201525082 funded by the Spanish Ministry of Economy and Competitiveness. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist. The main objectives of this paper are therefore, firstly, to present the new depositional context documented at Dehesilla Cave, supported by a wide range of empirical data obtained by interdisciplinary methods; and secondly, to place this find within the general context of the body of contemporaneous funerary data known at present in the Iberian Peninsula. This task implies a comparative approach, which enables not only the formulation of a likely interpretation of the new context presented here but also the systematic review of the current evidence available in the Iberian Peninsula. The specific and comparative information will therefore allow us to highlight the singular characteristics of the Locus 2 deposition, and to shed new light on the ritual funerary behaviours in practice during the Middle Neolithic throughout the Iberian Peninsula. 2. Data and methods The data presented in this paper are provided by the recent excavations carried out within the framework of the project “Dehesilla Cave: archaeological and environmental studies for the knowledge of the Prehistoric human occupation of the Sierra de Ca ´diz”, directed by one of the authors (DGR) (Fig 1). This project conducted a first excavation season in 2016 that led to the identification of several Medieval occupation phases outside the mouth of the cave [17,18], and a complete Neolithic sequence in the room of the cave nearest the entrance [19] in which previous excavations had been carried out in the 1970s and 80s [20]. The unpublished data presented here come specifically from the second excavation season, in 2017, and from the excavation area identified as C006 located in Room 4, one of the inner-most spaces of Dehesilla Cave. The data are diverse in nature: stratigraphic, osteological, isotopic, zoological, artifactual, botanical (seeds, fruits and wood) and radiocarbon results are presented here together. The work presented in this article does not raise any ethical issues. Although all of the scientific fields that support these results are merged successfully in archaeology, each one has specific techniques of data collection and processing. The location of trench C006 in the southern part of Room 4 (Fig 2) coincides with an area in which the surface flowrock was broken and absent (Unit 0). The irregular shape of the trench corresponds exactly with the limit of the flowrock. The excavated area is approximately 5 m 2 , with a maximum length of 5 m running parallel to the West wall of the cave and a width of approximately 1 m. Careful excavation confirmed that only the upper layers immediately beneath the surface level were affected by contemporary human and animal activities. Because the stratigraphy of caves usually become a palimpsest subjected to taphonomic processes [22], the excavation proceeded with great care with particular attention to the definition of the contacts between the stratigraphic units [23] and using total stations and laptops with the EDM Mobile software [24] to record topographically every archaeological element. The information was logged in a database easily exportable to storage and data management software, and adapted for the creation of spatial graphic outputs. Both the vertical stratigraphy and the microcontextual relationships of the elements associated with the deposition under study were clearly identified and documented and all of the archaeological materials and samples were duly recorded in their corresponding excavation units. From each and all of the Stratigraphic Units, 20% of the sediment was processed by flotation, and the rest was screened manually (2.5 mm size), with the exception of the samples set aside for specific analyses. Regarding the human osteological analysis, sex determination based only on the skulls was fraught by the absence of the mandibles. The method applied in first instance was based on the visual assessment of cranial morphological traits [25–28], morphometric variables [29,30], and the discriminant functions [31] based on an American sample from the Terry Collection. PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 3 / 46 Fig 1. Location of Dehesilla Cave (Theme map bases: [21]). https://doi.org/10.1371/journal.pone.0236961.g001 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 4 / 46 Fig 2. a) Location of Trench C006 on the three-dimensional plan of the cave; and b) Panoramic view from the Centre to the South of Room 4. https://doi.org/10.1371/journal.pone.0236961.g002 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 5 / 46 A probabilistic approach, developed by David Navega and based on the European population of the Howells’ Craniometric Dataset (n = 317, 153 females and 164 males, estimated sex), was also used. Two types of analysis were conducted using a random forest classification algorithm. Age at death was estimated through the assessment of cranial suture closure and dental wear, following several standard methods [32–36]. Strontium isotope analysis was carried out on both skulls. The basis of the technique is that the strontium isotope ratio of 87 Sr/ 86 Sr varies geographically with geology and that strontium moves into the chemistry of living being from rocks and sediment through the food chain [37– 39]. Human tooth enamel is the choice material for analysis [38,40–43] and the method provides a robust means for examining human mobility in the past. An essential question concerns the local strontium isotope signal for the area in which a burial is found, since levels of strontium isotopes in human tissue may vary from the geological background for a number of reasons [44–46]. It is therefore necessary to measure the bioavailable levels of 87 Sr/ 86 Sr, i.e. those actually available in the food chain, in order to ascertain local strontium isotope ratios. The local bioavailable isotopic signal of the place of burial was determined here from archaeological fauna provided from the cave. In particular, several samples of terrestrial snails (Otala lactea) from the same archaeological context Locus 2 and from area C004 were used, as well as another sample (Oryctolagus cuniculus) from the archaeological area C005 (located to a few meters from of Locus 2). A broader dataset of comparative baseline values is also provided by previous work in the region. The quantification methods applied in the archaeozoological analysis considered the determination of the number of identified specimens (NISP), weight (g) and the minimum number of individuals (MNI). The anatomical identifications (in the case of vertebrate species) and species determination of the osteological and dental elements has followed the specialised reference literature [47–49] and the bone and shell reference collections of the Instituto Andaluz del Patrimonio Histo ´rico and Estacio ´n Biolo ´gica de Doñana. The main aims of the pottery analysis, in line with the well-developed framework of archaeological ceramic analyses [50–54], were the assessment and reconstruction of the likely nature of the depositional and taphonomic processes leading to the creation of the assemblage under study, and the typological (formal and decorative) characterisation of the ceramic materials with regards to the fundamental questions of chronological and cultural attribution of the ritual funerary context under study. The quantification of the number of pottery fragments and the individual measurement of their size and weight enabled to fix a series of reference values for the fragmentation of each unit and/or spatial subdivision. Different methods for basic pottery quantification are discussed extensively in the above mentioned sources, and have indeed been an area of foremost interest and debate over many decades [e.g. 55]. After initial descriptive statistics, size was finally retained as the most appropriate proxy variable for the state of fragmentation of the assemblage under study. An exercise in refitting was carried out in addition, with the specific purpose of identifying sherds belonging to the same pots, with or without a direct physical refit. Both approaches clearly highlighted the sharp contrast between the predominant state of fragmentation and vessel representation (mostly single sherds) and that of the scarce yet very significant cases of pots represented by a larger number of fragments and proportion of the vessel. The stone tools were quantified and analysed in two main groups: knapped and polished stone. The study of the knapped materials followed works on analytical typology for retouch and extraction techniques [56,57], completing the definition of particular technical attributes [58], as well as the metric description [59]. The knapped material was grouped at the first level as Retouched and Unretouched. The first group includes tools, and retouched blades and flakes; the second group comprises unretouched blades, flakes, atypical fragments, cores, core PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 6 / 46 remains and debitage products, and chunks. Backing, patina and macroscopic use wear was determined by the observation of the edges with a 20x magnifying glass. The typo-technological analysis followed the main syntheses and terminological/lexical proposals for the western [60,61], southern [62] and eastern [63,64] regions of the Iberian Peninsula, whilst carrying out the appropriate adaptations to the characteristics of the Dehesilla Cave assemblage. Traceological analysis was carried out through the combined use of a Leica MZ16A binocular microscope with a range between 10x and 90x and an Olympus BH2 metalographic microscope with a range between 50x and 400x, coupled with a Canon 450D digital camera. Image software (Helicon Focus v. 4.62) was used to obtain completely focused images. Seeds and fruits were recovered by flotation. Large representative sediment samples were set aside during the excavation process of each stratigraphic unit, specifically one fifth of the total volume of each unit. All of the samples were processed in a flotation machine with a 1 mm mesh collector for the denser materials inside and a 0.25 mm mesh on the overflow for the lighter materials. After flotation both fractions were dried and transferred to the laboratory, where they were processed manually under a 10-15x magnifying glass. The identification of seeds and fruits was carried out in the laboratory of the Institute of History of the CSIC in Madrid, supported by a reference collection and the specialised literature. The denomination of wild taxa followed Castroviejo [65] and that of cultivates followed the binomial classification [66]. Two complementary quantification criteria were used: the ubiquity of each of the taxa and the number of remains. All anthracological remains larger than 2 mm were considered for analysis. Carbonisation preserves the cellular structure of wood which, observed under the microscope, enables the taxonomic identification of the charred remains [e.g. 67,68]. This task was performed under a Leica DP2500 incident light microscope. The taxonomic identifications were established through comparison with Schweingruber’s tree anatomy atlas [69] and the reference collection of charcoal at the ICArEHB at the Universidade do Algarve. After presenting all of the data obtained from the depositional context under study (Results), the Discussion offers an overview of the contemporaneous funerary contexts in the Iberian Peninsula dated within the 4800–4550 cal BC date bracket. A comparative analysis is carried out between the different known cases with emphasis on a range of parameters (type of burial, type of structure, burial area and associated structures, placement, orientation, pathologies and grave goods). This enables us not only to contextualise and interpret the new data but also to explore and infer the patterns and traits documented in the ritual funerary practices of this period in the Iberian Peninsula. 3. Results 3.1. Archaeological context Trench C006 has enabled the reconstruction of the stratigraphy of Room 4, the inner-most and furthest from the present day mouth of the cave, thus providing a relatively representative image of this area of the cavity. The 2017 excavation documented a complete stratigraphic sequence and enabled a number of observations regarding the characteristics and use of this chamber. The sequence includes several thick levels, which appear to correspond to geological events in which rocks, sediments and water may have been carried down from the adjacent Room 2 or possibly through the roof of the cave by means of cracks and chimneys. These levels display a descending south to north slope, from the mouth to the interior of the cave, and form a wedge-shaped accumulation in the southern half of the chamber. The anthropic sequence includes a number of levels, defined on the basis of their stratigraphic characteristics and PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 7 / 46 archaeological materials, belonging to different Neolithic periods (Fig 3). The lower levels date to the Early Neolithic. Of these, the upper level (Unit 8) displays a notable south to north descending slope, and is constituted in great part by medium to large sized limestone blocks, some up to 70 cm. The formation of this level appears to be due to collapse and torrential events. The upper contact of Unit 8 is the ground level on which the depositional event analysed in this paper took place, dated at some time between ca. 4800–4550 cal BC and with a material assemblage consistent with the Middle Neolithic (see below). The Units and Structures of interest here are Locus 2, the dividing Wall, Platform/Structure 1 and Hearth 7/9 (Figs 4and 5). Locus 2 is the fundamental element of the funerary context (and this name is therefore extended to the association of elements forming the deposition). Locus 2 is constituted by two human skulls, without the mandibles, and the main part of a very young sheep/goat, the remains of which were relatively well articulated. The area also yielded a notable pottery and stone tool assemblage. The two skulls were found approximately 20 cm apart, at a very similar level, in a clayey sediment with a medium to low compaction. The closest to the western wall of the cave was partially covered by a limestone block approximately 35 cm in length. The sheep/goat offering was placed by the second cranium. These three elements, carefully placed amongst medium sized limestone blocks, belong to a single depositional event, associated no doubt with the other structures documented in the same area. To the south of Locus 2 an alignment of large stones in an E-W direction was documented, forming a right angle with the western wall of the room. Spatially, these stones create a dividing wall (Wall) between the deposition and two other structures. The first is Platform/Structure 1. To the southwest of the wall, in the central area of the excavated area, where the cave wall forms a kind of natural niche, there is a stone structure, a platform of sorts created by the juxtaposition of stones placed at a very similar level (Platform/Structure 1). The shape of the structure is Fig 3. East section of C006. https://doi.org/10.1371/journal.pone.0236961.g003 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 8 / 46 approximately rectangular, with a maximum length (E-W) of 1,30 m and width (N-S) of 1 m. The outline of the structure, abutted to the West into the wall of the cave, is clearly defined to the North and South but not so clearly to the East. At the northwestern corner, by the cave wall, there was an upright stone placed vertically and outstanding above the other stones of the structure, with a flat face with geological (natural) crossed lines facing the platform. The second structure to the south of the dividing wall is the Hearth 7/9, constituted by Units 7 and 9. The former is a layer of ash, forming a circular area, approximately 0,40 m N-S Fig 4. Plan of the fourth stratigraphic phase (Middle Neolithic) in C006. https://doi.org/10.1371/journal.pone.0236961.g004 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 9 / 46 According to estimates based on 87 Sr/ 86 Sr in ancient sea water, the baseline values for these geological formations should be in the order of 0.7070–0.7080 [79]. Fig 10. Histogram of strontium isotope ratios from plant and animal remains from Andalusia. https://doi.org/10.1371/journal.pone.0236961.g010 Fig 9. Map of Western Andalusia with the location of strontium isotope reference samples. Black dots are human remains; red dots are plants and animals (Theme map bases: [21]). https://doi.org/10.1371/journal.pone.0236961.g009 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 16 / 46 Bioavailable strontium isotope ratios were measured directly on faunal remains recovered from the archaeological deposits of the cave. Four samples of rabbit bone and terrestrial snail shell (the latter from Locus 2 itself) were analysed in order to provide a precise local baseline. These values are shown in Table 1 and Fig 11 and cluster tightly between 0.7083 and 0.7085. The values obtained from the Locus 2 human samples are indicated on the same plot. The range of values exhibited by the samples from the two skulls, between 0.7083 and 0.7086, is very narrow, coinciding neatly with the baseline values provided by the faunal remains from the site. The range of values from the human and faunal samples is also a good match to the expected strontium ratios of the limestone landscape of the broader area of the sedimentary and Neogene Basins. These observations make it very likely that the human individuals Fig 11. Bar chart of fauna and human values from Dehesilla Cave. https://doi.org/10.1371/journal.pone.0236961.g011 Table 1. Results of Sr isotope analysis. Lab Code Dehesilla ID Context Species Sample 87 Sr/ 86 Sr F10290 DH17-22 C006-Locus 2Homo Skull 1 –PM1 Right 0.708371 F10291 DH17-23 C006-Locus 2Homo Skull 2 –PM2 Right 0.708509 10295 DH17-29 C006-Locus 2Otala lactea Terrestrial snails 0.708304 F10292 DH17-26 C004-Unit 9 Otala lactea Terrestrial snails 0.708298 F10293 DH17-27 C004-Unit 14 Otala lactea Terrestrial snails 0.708264 F10294 DH17-28 C005-Unit 3 Oryctolagus cuniculus Tibia 0.708431 https://doi.org/10.1371/journal.pone.0236961.t001 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 17 / 46 represented by the remains were local to southwestern Andalusia, and quite probably to the site itself or immediate surrounding area. 3.4. Grave goods 3.4.1. Animals. A relatively large animal bone assemblage was recovered from Locus 2 (Table 2), as well as the remains of naturally ocurring microvertebrates and moluscs. The animal remains have been taxonomically determined as belonging to Cervus elaphus,Sus sp., Ovis aries/Capra sp., Oryctolagus cuniculus,Otala lactea,Unionidae, as well as indeterminate remains of fish and shell, a turtle and other vertebrate and invertebrate species. This assemblage displays a fragmentation similar to that of the other stratigraphic levels in C006, in such as way that these remains may not be presumed to have been deliberately included in the depositional event. The presence of two freshwater molusc shells (Margaritifera auricularia) and a perforated marine molusc shell (Acanthocardia aculeata) upon Structure 1 are noteworthy exceptions, as is a bone tool (find number C006-120) placed between the two skulls. This well-worked spatula with notable abrasion marks from use was created on a deer metatarsal (Fig 12). To the east of the skulls (Fig 13, find number C006-109) the remains of an infantile sheep/ goat individual were found, which must have been sacrificed and deposited complete or near complete, as indicated by the elements in anatomical connection and order. No cut marks, tooth marks or thermoalterations were identified (Fig 14). Interestingly, not all of the skeletal elements were recovered. Specifically, the anterior right and posterior left extremities and the skull were absent (Table 3). The absence of six cervical vertebrae, seven thoracic vertebrae and the sacrum are also noteworthy. The taxonomic identification of the skeleton is complex. The presence of both Ovis aries and Capra hircus is known in contemporaneous and earlier levels, and therefore the sacrificed animal could belong to either of these two species or to Capra pyrenaica. The state of the fusion of the thoracic and lumbar vertebrae may indicate an age at death of less than ten days, following the parameters set out in a study of the Aragonese sheep breed [82]. According to this author, the arch of the thoracic vertebrae fuses before birth and the arch of the lumbar vertebrae within 10 days after birth. Table 2. Number of Identified Specimens (NISP) and Minimal Number of Individuals (MNI). The Ovis aries/Capra sp. Line includes the remains of the infantile sheep/goat found in Locus 2. There is no secure anatomical characteristic to distinguish bones from Ovis aries and Capra sp. The Class II mammals are those with a body mass between 18 and 200 kg [80,81] according to the decay processes of mammals in Mediterranean ecosystems. Taxa Locus 2 Structure 1 Unit 7 Unit 9 Ovis aries /Capra sp. NISP 49 1 MNI 2 1 Cervus elaphus NISP 1 1 1 MNI 1 1 1 Sus sp. NISP 3 1 MNI 1 1 Oryctolagus cuniculus NISP 8 9 1 MNI 2 2 1 Freshwater turtle NISP 4 MNI 1 Fish NISP 1 MNI 1 Class II mammals NISP 5 11 Indeterminate NISP 30 46 1 TOTAL NISP 100 1 70 1 https://doi.org/10.1371/journal.pone.0236961.t002 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 18 / 46 The age estimate of the animal may be of interest in relation to the approximate time of year at which the ritual deposition took place, although naturally this is subject to the uncertainties regarding the possible changes in the reproductive cycles of these species over time. At present, wild Caprinae usually have spring-time lambing seasons, when pastures are most abundant [83]: Capra pyrenaica (May-June), Capra aegagrus (April-May) and Ovis gmelini (May). In contrast, many present-day Iberian domestic sheep and goat breeds can give birth at any time of the year [84–86]. Artificial selection and productive interests have led to a nearcontinuous ovarian cycle [87] which, in some close modern breeds, for instance the Churra Lebrijana sheep, enables deliveries throughout the year. In other breeds the reproductive cycle has been intensified to reach more than one annual birth, or in others, for instance the Canarian sheep, births are concentrated before Christmas in order to suit consumer demand. However, in sheep breeds such as the Chamarita, in extensive exploitation systems, births are concentrated between May and June; in the Castellana breed between February and March; in the Charmoise breed, 75% of births occur between March and April; and in the Alcalarreña breed they are concentrated between February and March [84]. With the modern management of goat herds, it is also possible to reproduce these animals throughout the year, although for some the highest frequencies of births are concentrated in particular seasons [86]. For instance, for the Payoya goat, an autochthonous Andalusian breed from the same area as the Fig 12. Bone spatula made from a deer metatarsal, with extensive use wear. https://doi.org/10.1371/journal.pone.0236961.g012 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 19 / 46 Fig 13. Plan and sections of Locus 2 with a precise spatial location of the offerings. The two sections correspond to the perpendicular dashed lines indicated on the plan. https://doi.org/10.1371/journal.pone.0236961.g013 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 20 / 46 Fig 14. Laboratory image of the young sheep/goat skeleton. https://doi.org/10.1371/journal.pone.0236961.g014 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 21 / 46 archaeological site, 85% of births are concentrated between August and November and between December and February, for the Blanca Serrana Andaluza breed between March and April or for the Negra Serrana in Spring or Autumn [85]. If we assume that the Neolithic domestic sheep and goat had reproductive cycles marked by the environment of the region, the animal could have been sacrificed and offered ritually coinciding perhaps with the beginning of Spring. This seems to be the case for other Iberian Neolithic archaeological sites [88], although this particular point must remain open, since greater knowledge is needed on the human selective pressures on Iberian Neolithic herds. 3.4.2. Pottery. The pottery assemblage is fairly large, especially in the immediate environment of the skulls (Locus 2) and the hearth (Units 7 and 9). However, an important issue concerns the inclusion of pottery vessels in the deposition, and their use in specific activities. Answering this question requires a detailed analysis of the general patterns of fragmentation and representation in the depositional units of interest here (Table 4). Based on the quantitative evidence, two processes of entry into the archaeological record can be proposed for the pottery record. Indeed, most of the assemblage displays a very high fragmentation, and a very low representation, that is, most pottery records correspond to single fragments from different vessels. In Unit 7, impressed, incised and engraved decorative techniques coexist without any clear pattern. It should be noted that these pottery fragments are not usually burned or altered Table 3. Anatomical remains of the Ovis/Capra skeleton found in Locus 2. Bones Left Right Cervical vertebra 1 Dorsal vertebrae 5 Lumbar vertebrae 7 Ribs 7 6 Rib fragments 2 Sternum 3 Scapula 1 Humerus 1 Radius 1 Ulna 1 Metacarpus 1 Pelvis 1 Femur 1 Patella 1 Tibia 1 Metatarsus 1 Phalanx I 1 Phalanx II 4 Phalanx III 1 TOTAL 47 https://doi.org/10.1371/journal.pone.0236961.t003 Table 4. Summary of the pottery assemblage fragmentation patterns (individual fragment size range and average). Excluding the partially reconstructed vessels (see Table 5). Unit Nºof fragments Size Range Size Average UE 7 76 1,5–8 cm 3,6 cm UE 9 8 2–8,5 cm 4,3 cm UE 8 Locus 2 171 1–8 cm 3,5 cm https://doi.org/10.1371/journal.pone.0236961.t004 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 22 / 46 by fire. Meanwhile, in Locus 2 there is a greater frequency of engraved decoration. The relative importance (frequency) of engraved pottery in the units conforming the ritual deposition must be noted, as well as the coexistence of two well-known products for the site, impressed and incised pottery, with different technological and stylistic characteristics. In any case, it seems that a large part of the fragmentary pottery assemblage may not be directly associated with the ritual funerary event. In contrast, there is a smaller set of fragments belonging to four separate vessels, for which a relatively larger proportion is preserved, and that appear to have been deliberately deposited at the time of the ritual (Table 5). First of all, there is a group of 10 fragments linked to Unit 7, the upper layer of the hearth, with physical connections between all the fragments (Fig 15, Id. 14). The conjoining fragments enable the reconstruction of approximately one-third of a closed, fine-walled bowl with a high quality surface treatment and unique decoration within the Dehesilla pottery repertoire known to date. Specifically, it is decorated with an engraved and staged schematic motif. It has 11 or 12 radial lines arranged from the base, with a possible progressive evolution of the initial design. At least one of the radial lines structures a series of semi-circular shapes, smaller in the upper area (below the rim edge) and larger in the central area of the bowl, filled with horizontal or oblique parallel lines (Fig 16). The physical relationship of all the recovered fragments with no ’orphan’ sherds suggests breakage with little subsequent dispersal of the fragments. Secondly, there is a set of 8 fragments found in Locus 2 that were directly associated with the sheep/goat described above, and belong to part of a large bowl with a burnished inner surface (Fig 15, Id. 19). It preserves a maximum reconstructed vertical measurement of 13 cm. The preserved portion of the bowl displays a schematic engraved decoration: a band of repetitive semi-circular shapes under the rim upon a horizontal line from which vertical areas alternating smooth spaces and spaces formed by several vertical bands (up to 6 observed in the preserved fragments) filled with parallel horizontal lines are delimited. In contrast, the vertical fill of the semi-circles appears to be deliberately criss-crossed, drawn towards the rim. In two conjoining fragments the outer line of the vertical band is highlighted by small excised triangles. The vessel shows an interesting possible firing effect, with a blackish edge to contrast with a light brown body. Many of the conjoining fragments were found in proximity to each other and to the infantile animal skeleton (Fig 13, Id. 19 and 109, respectively). Therefore, a direct relationship can be inferred between the deposition of this vessel and that of the possible sacrificial sheep/goat. Thirdly, a set of 5 fragments has also been documented in Locus 2, 4 of them rim sherds, representing over 35% of the circumference of the mouth, but with a maximum preserved vertical measurement of only 10 cm, equivalent to the rim and neck of an apparently undecorated pot (Fig 15, Id. 63). Three other fragmentary and amorphous sherds share very similar physical characteristics, but lack a physical connection. They appear all to belong to a plain, truncated inverted cone necked vessel, with even compact walls (6 mm) and very smooth burnished Table 5. Fragmentation and representation of the intentionally deposited pots. Pottery Record Id. Nºof fragments Maximum preserved vertical measurement Total Weight Hearth Unit 7 –Id. 14 10 9.5 cm�202 g Locus 2 –Id. 19 8 13 cm 165 g Locus 2 –Id. 63 5 10 cm 194 g Locus 2 –Id. 70 2 19.5 cm�408 g �Complete vessel height. https://doi.org/10.1371/journal.pone.0236961.t005 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 23 / 46 Fig 15. Pottery vessel offerings or burial goods from Locus 2. https://doi.org/10.1371/journal.pone.0236961.g015 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 24 / 46 surfaces. Some of the fragments are also partially coloured in black, probably altered by fire. Fig 13 shows the position of the fragments in the immediate vicinity of the male skull (Cranium 2). Finally, two fragments of the rim and body and base of a single container were documented in Locus 2 and were associated with the dividing wall between the skulls and the hearth (Fig 15, Id. 70). This pot is bucket-shaped, with subvertical walls, a flat base, and no decoration. It is tentatively included in the group of outstanding pottery vessels because of the size of the fragments, which is much larger than the average for these units, and the preservation of the nearcomplete section. 3.4.3. Stone tools. A total of 31 stone tools have been documented (Table 6 and Fig 17), with an overall proportion of 45.16% of knapped lithic industry and 54.83% of polished stone. The former includes both the lithic products and the elements associated with their production, cores (14.29%) and reduction products (platform preparation and debitage, 7.14% each). Fig 16. Schematic ideal reconstruction of the decoration of vessel 7–14. https://doi.org/10.1371/journal.pone.0236961.g016 Table 6. Lithic assemblage. Units Total Typology NºRetouched tool % Use-wear % 7 3 Knapped 33.3% Blade 100% 1 0 – 0 – Flake 0 0 0 Polished 66.7% Quern 50% 1 – – 2 100% Hand grinder 50% 1 9 1 Knapped 100% Blade – 0 1 100% 1 100% Flake 100% 1 Locus 2 24 Knapped 50% Blade 41.7% 5 4 33.3% 2 16.66% Flake 33.3% 4 0 Core 16.7% 2 0 Debitage 8.3% 1 0 Polished 50% Hand grinder 16.66% 2 – – 9 75% Blade 16.66% 2 Polishing stone 16.66% 2 Indeterminate tool 16.66% 2 Ochre 16.66% 2 Unworked stone 16.66% 2 Structure 1 3 Polished 100% Stele 33.3% 1 – – 1 33.3% Quern 33.3% 1 Unworked stone 33.3% 1 https://doi.org/10.1371/journal.pone.0236961.t006 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 25 / 46 is of great relevance, therefore, not only because of the scarce knowledge of the funerary practices of this period, but also because of its own singular characteristics. 4.2. The funerary record dated between 4800–4550 cal BC in the Iberian Peninsula Table 10 contains only the known funerary sites with radiocarbon dates between 4800–4550 cal BC. The majority of burial evidence for this period in the Iberian Peninsula comes from primary Table 10. Available radiocarbon dates from archaeological sites with funerary evidence between 4800–4550 cal BC. Site Context Sample BP Date CAL BC (2 sigma) Lab Code References Cerro Virtud Phase II Homo 6030 ±55 5200–4780 OxA-6714 [100] Phase II Charcoal 5920 ±70 4990–4610 Beta-90885 [100] Phase II Charcoal 5895 ±55 4910–4610 OxA-6715 [100] Phase II Charcoal 5860 ±70 4910–4540 Beta-101425 [100] Phase II Homo 5840 ±80 4900–4490 OxA-6580 [100] Phase II Sediment 5830 ±90 4910–4460 Beta-118938 [100] Phase II Homo 5765 ±55 4730–4460 OxA-6713 [100] Phase II Charcoal 5660 ±80 4690–4350 Beta-90884 [100] Cueva del Toro Phase IV Charcoal 6030 ±70 5210–4720 GrN-15444 [101] Phase IV Homo 5980 ±40 4988–4772 Beta-365292 [102] Phase IV Charcoal 5820 ±90 4900–4460 GrN-15440 [101] Salemas Homo 6020 ±120 5230–4670 Icen-351 [103] Paternanbidea Burial 2 Homo 5960 ±40 4942–4728 GrA-13675 [104] Los Cascajos Structure 196 Homo 5945 ±95 5191–4555 Ua-24423 [104] Structure 265 Ovis capra 5640 ±75 4660–4300 Ua-16025 [105] Cova de l’Avellaner Cav. Sepul. 3a Homo 5830 ±100 4935–4460 UBAR-109 [106] AV-CO I-X 25 Homo 5941 ±34 4930–4725 CNA3304 [107] Cueva de los Murcie ´lagos, Albuñol Esparto 5900 ±38 4850–4680 CSIC-1134 [108] Esparto 5861 ±48 4850–4590 CSIC-1132 [108] Tossal de les Basses Stone floor; UE34 Seed 5880 ±50 4850–4600 Beta-232484 [109] Drainage ditch(4121) fill (149) Seed 4720–4520 Beta-232483 [110] Burial 2–1819 Homo 4590–4450 Beta-225216 [110] Burial 9–11471 Homo 4590–4450 Beta-225223 [110] Castelo Belinho Structure 3 Venerrupis 5880 ±55 4904–4598 Sac-2030 [111,112] Structure 4 Homo 5720 ±40 4685–4462 Beta-199913 [111,112] Structure 53 Homo 5662 ±32 4582–4374 Wk-28000 [111,112] Barranc d’ en Fabra Post hole Charcoal 5880 ±110 5040–4510 BETA-61490 [113] Cueva de Nerja Vestı ´bulo. NE (1NE) Nerja-1-1829. Homo 5875 ±80 4940–4540 Ua-12467 [114–116] Torca. South Sect. NT 11e Charcoal 5789 ±40 4730–4530 Beta-168972 [116,117] Torca. South Sect. NT-11c Charcoal 5760 ±40 4710–4500 Beta-195999 [116,117] Sala del Cataclismo Charcoal 5770±40 4717–4526 Beta-270018 [118] Charcoal 5760 ±40 4710–4505 Beta-195998 [116] Charcoal 5740 ±40 4696–4491 Beta-270037 [119] El Padro ´II Charcoal 5870 ±100 4984–4499 UBAR-115 [120] Charcoal 5770 ±80 4822–4451 UBAR-114 [120] Charcoal 5600 ±130 4768–4076 UBAR-113 [120] Charcoal 5580 ±130 4719–4070 UBAR-116 [120] Cueva de la Carigu¨ela CIV 5, Level I-5 5690 ±30 4610–4450 Pta-9162 [121] https://doi.org/10.1371/journal.pone.0236961.t010 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 32 / 46 burials, with only a few disarticulated or isolated remains documented (Fig 20 and Table 11). Secondary burials are rare, and the exclusive deposition of skulls is extraordinary. Only Cueva del Toro can be added to the case of Dehesilla Cave, although the former may belong to an earlier chronological phase corresponding to the traditional Andalusian Early Neolithic [109], that is to a period during which this type of deposition appears to have been more common. In the sample available and analysed here, with the exception of the frequent isolated remains and the secondary burials at Cueva de los Murcie ´lagos and Cerro Virtud, the funerary spaces generally include several burials, in variable numbers, leading to their interpretation in some cases as collective burial areas, or even as true necropolis (Paternanbidea and Castelo Belinho). Fig 20. Location of the archaeological sites with funerary evidence for this period throughout the Iberian Peninsula: 1) Cueva de la Dehesilla; 2) Cueva de Nerja; 3) Cueva de los Murcie ´lagos de Albuñol; 4) Cueva de la Carigu¨ela; 5) Cueva del Agua; 6) Cueva de El Toro; 7) Cerro Virtud; 8) Cova d l’Avellaner; 9) El Padro ´; 10) Los Cascajos; 11) Paternanbidea; 12) Barranc d’en Fabra; 13) Tossal Basses; 14) Castelho Belinho; and 15) Salemas. (Theme map base: [122]. These sites are described in the same order in Table 11). https://doi.org/10.1371/journal.pone.0236961.g020 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 33 / 46 Table 11. Ritual features of funerary sites throughout the Iberian Peninsula. Site Site Type Human bones Burial structures Associated structures Position Orientation Pathology Offerings / material culture References Access difficulty Cueva Dehesilla Cave Crania without mandibles Area delimited by stone blocks and wall Hearth and stone platform 1: Skull to S facing E; Incomplete trepanation; cut mark on the occipital bone Young sheep/goat, 4 pots, lithics, Triticum, Olea europea,Pinus pinea/pinaster, Quercus ilex/coccifera, Ericaceae and Pistacia [21] Difficult 2: Skull to N facing W Cueva Nerja Cave Individual burial and relocated remains Simple pit None Dorsal decubitus? NW-SE Dental wear Iberus alonensis, limestone object [114,115] Easy Cueva Murcie ´lagos Cave Primary and secondary burials Communal room — — — — Basketry, Papaver somniferum [108,123] — Cueva Carigu¨ela Cave Individual burials and relocated remains — Hearths (habitat?) — — Evidence of flesh removal? Schist, limestone and marble bracelets, beads? [7,123– 125] Intermediate Cueva Agua Cave Individual burials Pits marked by stone blocks Hearth (both) Lateral decubitus (both) — — Undecorated bowl [126,127] — Flint blades, fossil corral, limestone bracelet? Cueva Toro Cave Skull and other parts (secondary burial?) None — — — Incisions (flesh removal) Ochre [101,128, 129] Difficult Two undecorated bowls and the base of a third Cerro Virtud Open air Primary and secondary burials and isolated remains Collective pit Hearth, delimitation stones (wall) Left lateral decubitus W; E; N or S? — Undecorated pots and bowls, flint lithics, beads (stone and shell), perforated Columbella rustica [100,130] Cova Avellaner Shelter Disarticulated remains None Separation walls — — Caries, periodontitis and arthritis Montbolo ´style pottery, lithics, spatulas and other bone tools, bracelets, beads, perforated wild boar tusks, Cardium edule shells and faunal remains [3,107] El Padro ´Open air Individual burial Grave — Flexed (lateral decubitus?) — — Motbolo ´style geometric pottery, arrowheads [3,15,131] Los Cascajos Open air Individual burial Pit Habitat structures and hearths Flexed (lateral decubitus?) — — Bowl and other impressed and sgraffito pottery, bone tools and horn awls, hand grinders [104,105, 132] Paternanbidea Open air Individual burials Pit Habitat structures — NE-SW, heads to the E-NE — Impressed bowl, geometric microliths, beads and bracelet [104,133] Barranc Fabra Open air Powdered remains Vertical stone slab structures Habitat structures — — — Pottery bottle, lithics, bracelets and shell (Pecten,Cardium) and limestone beads [3,113, 134] (Continued) PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 34 / 46 The type of funerary structure characteristic of the known burials is usually the individual grave, in some cases delimited by stone blocks, although there are examples where the burials were placed directly on the ground. In caves, the information available on the spatial location of burials is sparse. At least at Dehesilla Cave and perhaps Cueva de la Carigu¨ela, areas of difficult access appear to have been preferred, as they are the furthest away from the entrance to the cave and/or because they constitute geomorphologically inaccessible spaces. However, an opposite example is provided by the location of burials at Cueva de Nerja. In a large part of the comparative sites, the burial contexts usually display combustion structures or hearths. There are hardly any known cases of other associated structures in caves. Dehesilla Cave has a delimitation or boundary wall between the deposition of the skulls and the rest of the associated structures: the aforementioned hearth and a stone platform. Cova de l’Avellaner also has walls creating the spatial differentiation between the three cavities of the shelter. And at Cueva del Agua, one of the burial pits displayed a stone paving, cover and perimeter ring. In the case of funerary contexts located in the open, there is a delimiting wall between a hearth and the deposition of the bodies in the collective grave of Cerro Virtud. At open-air sites that also display habitat contexts, there are not only hearths, but also numerous types of pits and negative features, as well as huts of different shapes. With the exception of Nerja, the bodies are usually placed in a lateral, more or less flexed position. The orientation of the burials is extremely varied, and does not appear to show significant differential patterns. Paleopathological analyses are scarce and probably unequal in different osteological assemblages. In relation to the skulls from Dehesilla Cave (one showing possible trepanation and cut mark), the possible evidence of defleshing from Cueva de la Carigu¨ela is worthy of special mention. A similar observation applies to the availability of information regarding funerary offerings. The reliability of data regarding burial goods is even more uneven between sites, especially since some of it comes from relatively old excavations. However, several aspects can be noted. Animal offerings are not common. Apart from Dehesilla Cave, only a very few cases are known: Cova de l’Avellaner with sheep/goat and deer remains, and Castelo Belinho, as well as the indeterminate remains of ritual pit nº256 at Los Cascajos -without human remains but perhaps associated with other burial pits. Shells (malacofauna) are more common, having been documented at Cueva de Nerja, Cerro Virtud, Cova de l’Avellaner, Barranc d’en Fabra and Castelo Belinho. Most of the analysed deposits contain pottery. In many of them, they are Table 11. (Continued) Site Site Type Human bones Burial structures Associated structures Position Orientation Pathology Offerings / material culture References Access difficulty Tossal Basses Open air Individual burials Pits Habitat structures Lateral decubitus N-S; Head to the W; NW — Tomb 14: three complete pots, characteristic of the postcardial or comb decorated horizon [110,135] Castelo Belinho Open air Individual burials Pits Habitat structures Lateral decubitus — Caries Bowls and globular pots, Glycymeris bimaculata bracelets, flint flakes and blade, hammers and querns, ochre and fauna [112] Salemas Open air Individual burials Karst depressions Habitat structures — — — Boquique style impressed pottery [136] https://doi.org/10.1371/journal.pone.0236961.t011 PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 35 / 46 entirely or essentially plain pots -for instance at Cueva del Agua, Cueva del Toro, Cerro Virtud, Cova de l’Avellaner, El Padro ´, Los Cascajos and Tossal Basses. Two of the four vessels directly associated with the deposit at Dehesilla Cave are undecorated. There is evidence of knapped lithic industry in one third of the funerary contexts analysed, and regarding polished stone industry the fragments of grinding stones and the possible use of ochre at Castelo de Belinho provide similar evidence to that documented at Dehesilla Cave. In Locus 2, the entire bone tool repertoire is limited to one spatula made from a deer metatarsus. At the rest of the comparative sites, bone industry is minority, if not altogether absent, with the exceptions of Los Cascajos and the extraordinary case of Cova de l’Avellaner, with a numerous and diverse bone assemblage. The results of possible carpological and anthracological analyses in the contexts analysed here have not generally been made known, thus no comparisons can be made. 4.3. Interpretative possibilities of the Locus 2 deposition The Locus 2 depositional context at Dehesilla Cave displays several characteristics that are different from those of the rest of the known funerary contexts of the 4800–4550 cal BC period in the Iberian Peninsula. The exclusive selection and (re)burial of the skulls is contrary to its interpretation as a primary burial. It is the only case dated with certainty to the Middle Neolithic that indicates a selective treatment and burial of human skulls (without the mandible). It also provides a novel archaeological context with several structures as peculiar as the stone platform described above (Structure 1). These exceptional characteristics may correspond to the hypothesis of a deposit (and activities) with a strong ritual component, beyond that which is usually shown by the archaeological record related to the common (or normative) burials of these populations. The very location of the deposition in one of the areas furthest from the cave entrance, in a sort of hidden and secluded chamber, is suggestive in this sense. Deciphering these possible ritual activities is clearly no simple task, but at least the possible lines of interpretation of this record can be tentatively pointed out. The possibility of being a deposit of isolated individuals, as a kind of funerary ostracism, does not seem to be in line with the investment in the creation of the documented stone structures. The ex novo purpose-specific construction of these structures is also not usual in normal Neolithic secondary burials. Based on the durable elements of the archaeological record, the practices involved in secondary burials are usually limited to the selection of all or only part of the remains to be moved between locations, but without the association of structures such as those documented in this case and without additional rituals such as the sacrifice and in situ deposit of the infantile sheep/goat. Although the possibility that either of the skulls (or at least Cranium 2) could have come from a primary burial prior to deposition cannot be completely ruled out, it must be emphasised that, among the funerary contexts dated in the same chronological period throughout the Iberian Peninsula, the practice of primary burial is predominant, and secondary burial is only rarely documented (if at all at the Cueva de los Murcie ´lagos and Cerro Virtud). In any case, the characteristics of this deposit indicate some type of singular and intentional social treatment by the community through the enactment of a special deposition with a strong ritual component. Along these lines, the deposit may indicate some type of honorary recognition, related to social leaders, perhaps great figures or religious guides. The presence of the cut mark on the occipital of Cranium 1 was performed post-mortem, but before the loss of muscle tissue, and therefore hypothetically as a means of separation of the skull or decapitation of the individual. Although it cannot be stated categorically, it is quite possible that death was chronologically close to the time of deposition of the skull (if not at the time of death itself, before complete tissue decomposition). This same (female) individual had PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 36 / 46 also previously suffered a probable incomplete trepanation, during life, since the bone regeneration observed indicates that this happened years before her death. This previous event may therefore have no direct relation to the events and ritual now examined. On the male skull (Cranium 2) no cut marks or evidence of this kind has been observed. However, the stratigraphic information guarantees the contemporaneous deposition of both skulls and several other elements of the context. Although the simultaneous natural death of both individuals (or the above mentioned secondary burial of one of them) cannot be ruled out, the natural death one and the ritual sacrifice of the other, or the sacrifice of both, may be equally likely. The empirical data thus opens up new anthropological scenarios, perhaps sacrifices (human and animal) related to propitiatory activities, divine prayers and/or commemorative festivities (cosmogonic, seasonal rites. . .). In this sense, it is necessary to recall the possible seasonal character of the deposition in Spring (based on the plausible sacrifice of the young sheep/goat) and, indeed, to highlight the stone platform, located within a natural niche in the cave wall, which may have functioned as a kind of altar, and also the decorative features of the two engraved pottery vessels, one of them physically associated to the body of the young sheep/goat and the other found in the hearth. The latter, in fact, displays a unique composition, a possible dynamic schematic scenary formed by a series of vertical branching motifs that occupy almost the entire height of the vessel. The repetitive motif appears sometimes in other Neolithic pottery cases [137–139] but also recalls certain vegetal motifs of Iberian rock art (named ‘ramiform’ or branch-shaped [140]), and indeed is common in caves and shelters throughout the region [see for example 141–144]. Therefore, the relationship previously suggested by other authors between Neolithic pottery decoration and schematic cave art [108, 145] is certainly a line to follow up in future. Some of the possibilities mentioned above, especially those that indicate the possibility of a temporal sequence in the completion of the depositional context, would imply a succession of ritual events in accordance with one or several of these interpretative scenarios, in which some kind of ancestral cult could also be present. 5. Conclusions Given the relatively diverse panorama, it is worth asking if there was in fact a cultural homogeneity behind the peninsular funerary record between 4800–4550 cal BC. It is interesting that Andalusian funerary evidence for this period comes from caves, with the exception of the anomalous case of Cerro Virtud. Meanwhile, in the rest of the Iberian Peninsula where funerary evidence from this chronological period exists -that is, fundamentally in the eastern half of the peninsula, and the occasional case in South and Central Portugalit comes instead from open-air sites (with the exception of the Cova de l’Avellaner shelter). It is unlikely that this dichotomy could be due solely to methodological biases in the surveying and search for prehistoric sites in the different regions. Moreover, most of these regions also have shelters and caves, so the differential availability of suitable sites cannot be the only explanatory factor either. It is therefore possible to think of a cultural mosaic in the funerary traditions of the Iberian Peninsula during these centuries of the first half of the 5 th millennium cal BC, leading to the observed dichotomy between the Andalusian region and, particularly, the eastern half of the peninsula. In the former, similarly to the southern regions of Portugal, open-air burials only appeared towards the end of the 5 th and especially during the 4 th millennium cal BC, many of them associated with the emergence of ditched enclosures and megalithic monuments. Despite this possible caveat regarding the heterogeneity of the funerary rites of this chronological interval in the Iberian Peninsula, taken as a whole it is possible that there may be a greater similarity between the practices of the early Middle Neolithic and the funerary customs PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 37 / 46 of the previous Early Neolithic than between the former and those of the period after the mid5 th millennium cal BC. This point of discussion requires a systematic comparative approach to the overall body of Neolithic funerary evidence, which greatly exceeds the scope of the present work. However, the basis of the hypothesis may be disclosed as the observation that the bulk of the funerary evidence is found within habitat areas, either in caves or outdoors. Only in the cases of Paternanbidea and Castelo Belinho the burials form a more or less specific funerary area, a kind of necropolis. These, however, already display some of the characteristic features of later sites, some of them with numerous excavated features, small circular pits and large enclosures, and/or megalithic constructions. Close to Dehesilla Cave, for example, representative sites of the funerary rites of the end of the 5 th and 4 th millennia cal BC are the settlements of Campo de Hockey [146] and the megalithic necropolis of Cañada Real and El Palomar, at Los Molares [147], or the megalithic necropolis of Alberite [148]. More or less contemporaneous is the well-known horizon of the pit fields of the northeast of the peninsula. This possible greater cultural distance between the records of the two periods may be at least partially due to the alleged population decline during the traditional Middle Neolithic period, although this general demographic dynamic surely had great differences and regional rhythms throughout the Iberian Peninsula. This panorama can be generally extrapolated to the best-part of the Iberian Peninsula. The number of radiocarbon dates available for the two central quarters of the 5 th millennium cal BC is notably lower than for the previous and subsequent periods (Early and Late Neolithic, respectively) [cf. 149]. In the south of the Iberian Peninsula, the site of Los Castillejos, in Las Peñas de los Gitanos (Montefrı ´o, Granada), is of particular relevance in this regard, due to the intense program of archaeological activities carried out, and where a period of abandonment of the site has been documented between ca. 4800-4400/4200 cal BC [150]. In fact, this specific period has very few chronological parallels in Andalusian sites that are well dated from domestic and/or short-lived elements, although there are some scarce dates that cover the second and third quarters of the 5 th millennium BC from a scatter of cave and open-air sites in the Mediterranean coastal regions and southeast Andalusia. If there were a similar hiatus at Dehesilla Cave, however, it may only have been a little later, from the middle of the 5 th millennium cal BC, in the period known as Middle Neolithic B, where it is noted, for example, that the volume of archaeological material remains decrease sharply with respect to the previous period analysed in this work [19]. If this hypothesis were true, the lower number and density of populations during this period might have caused a greater isolation of the groups from one another, and therefore led to a lower rate of interaction and horizontal transmission than those of the Early Neolithic and, of course, of the Late Neolithic, when numerous new features are differentially replicated and transmitted rapidly between populations, such as the emergence of pit enclosures and the consolidation of necropoli, as well as megalithism from the beginning of the 4 th millennium cal BC. At any rate, Locus 2 of Dehesilla Cave constitutes an extraordinary find and an important contribution to the current funerary evidence available in the Iberian Peninsula for the 5 th millennium BC. It has provided a great wealth of data that converges towards the ritual nature of this deposition. Moreover, its discovery opens up new possibilities for understanding the symbolic and the ritual social behaviours of the Neolithic agricultural populations of the western regions of the Mediterranean. Acknowledgments A number of important people and entities have collaborated with logistic support and diverse resources for the tasks developed by the Dehesilla Project during the 2017 season: Algar Local PLOS ONE Locus 2 at Dehesilla Cave and Middle Neolithic ritual funerary practices PLOS ONE | https://doi.org/10.1371/journal.pone.0236961 August 13, 2020 38 / 46 Council, Jerez de la Frontera Archaeological Museum, EvoCultura-Association for the study of human behaviour and cultural diversity, as well as the Dı ´az Romero family. Drs João Cascalheira and Ce ´lia Gonc¸alves from ICArEHB, Universidade do Algarve, have helped with the fine-tuning of the georreferencing system implemented in the field. David Navega, Universidade de Coimbra, has provided support in the sexual determination of the two skulls presented in this paper. Daniel Garcı ´a Rivero personally thanks his team of collaborators for their help in both the archaeological excavations and the processing and documentation of the finds during 2017: David Lo ´pez Carmona, Patricia Virino Gabella, Araceli Barrera Cruz, Pablo Gutie ´rrez Franco, Jerico ´Mancera Jime ´nez and Elena Trujillo Godoy. Finally, we would like to thank the interest of the Editors of PLoS ONE and the helpful comments by Joan Bernabeu and two other anonymous reviewers. Additional information regarding specimens: No permits were required for the described study, which complied with all relevant regulations. Author Contributions Conceptualization: Daniel Garcı ´a-Rivero. Funding acquisition: Daniel Garcı ´a-Rivero, Cla ´udia Umbelino, Eloı ´sa Berna ´ldez-Sa ´nchez, Leonor Peña-Chocarro, Juan F. Gibaja-Bao. Investigation: Daniel Garcı ´a-Rivero, Ruth Taylor, Cla ´udia Umbelino, T. Douglas Price, Esteban Garcı ´aViñas, Eloı ´sa Berna ´ldez-Sa ´nchez, Guillem Pe ´rez-Jordà, Leonor Peña-Chocarro, Marı ´a Barrera-Cruz, Juan F. Gibaja-Bao, Manuel J. Dı ´az-Rodrı ´guez, Patricia Monteiro, Juan C. Vera-Rodrı ´guez, Javier Pe ´rez-Gonza ´lez. Project administration: Daniel Garcı ´a-Rivero. Resources: Daniel Garcı ´a-Rivero, Ruth Taylor, Cla ´udia Umbelino, T. Douglas Price, Esteban Garcı ´aViñas, Eloı ´sa Berna ´ldez-Sa ´nchez, Guillem Pe ´rez-Jordà, Leonor Peña-Chocarro, Marı ´a Barrera-Cruz, Juan F. Gibaja-Bao, Manuel J. Dı ´az-Rodrı ´guez, Patricia Monteiro, Juan C. Vera-Rodrı ´guez, Javier Pe ´rez-Gonza ´lez. Supervision: Daniel Garcı ´a-Rivero, Ruth Taylor, Cla ´udia Umbelino, T. Douglas Price, Eloı ´sa Berna ´ldez-Sa ´nchez, Leonor Peña-Chocarro, Juan F. Gibaja-Bao, Juan C. Vera-Rodrı ´guez. Visualization: Daniel Garcı ´a-Rivero, Ruth Taylor, T. Douglas Price, Esteban Garcı ´aViñas, Guillem Pe ´rez-Jordà, Marı ´a Barrera-Cruz, Juan F. Gibaja-Bao, Manuel J. Dı ´az-Rodrı ´guez, Patricia Monteiro, Javier Pe ´rez-Gonza ´lez. Writing – original draft: Daniel Garcı ´a-Rivero, Ruth Taylor, Cla ´udia Umbelino, T. Douglas Price, Esteban Garcı ´aViñas, Guillem Pe ´rez-Jordà, Marı ´a Barrera-Cruz, Juan F. GibajaBao, Patricia Monteiro. Writing – review & editing: Daniel Garcı ´a-Rivero, Ruth Taylor, Cla ´udia Umbelino, T. Douglas Price, Esteban Garcı ´aViñas, Eloı ´sa Berna ´ldez-Sa ´nchez, Guillem Pe ´rez-Jordà, Leonor Peña-Chocarro, Marı ´a Barrera-Cruz, Manuel J. Dı ´az-Rodrı ´guez. References 1. Bernabeu J, Molina L, Garcı ´a Puchol O. El mundo funerario en el horizonte Cardial valenciano: Un registro oculto. Sagvntvn. 2001; 33: 27–36. 2. Pascual JL. Incineracio ´n y cremacio ´n parcial en contextos funerarios neolı ´ticos y calcolı ´ticos del este peninsular al sur del Xu ´quer. In: Kunst M, Rojo MA, coords. 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