Veget Hist Archaeobot (2017) 26:143–157 DOI 10.1007/s00334-016-0590-y

REVIEW

The first herders in the upper Ebro basin at Los Husos II ´ lava, Spain): microarchaeology applied to fumier deposits (A Mo´nica Alonso-Eguı´luz1,2 • Javier Ferna´ndez-Eraso1 • Rosa Marı´a Albert2,3

Received: 30 June 2015 / Accepted: 5 October 2016 / Published online: 18 October 2016  Springer-Verlag Berlin Heidelberg 2016

Abstract Fumier deposits are the product of the recurrent use of caves and rock shelters for stabling livestock and the periodic burning of the resulting dung. Their chronologies in the Mediterranean area extend from Neolithic times up to the Bronze Age, but they are scarce in or absent from Iron Age sites. The study of these deposits has provided important information to better understand past livestock and husbandry practices. The archaeological site of Los ´ lava, in the upper Ebro basin, Spain, dating to Husos II, A 6,990–6,770 cal BP, represents one of the earliest pieces of evidence for animal domestication in the Basque Country. The Ebro basin is particularly important, since this was the main route by which the Neolithic economic system spread from the Mediterranean coast to the northern Iberian Peninsula and the western Pyrenees. We present here the results of the study of the fumier deposits from the Neolithic Levels IV to IX of Los Husos II, through analyses of phytoliths, faecal spherulites and ash pseudomorphs. The main goal was to discover the ways in which Neolithic populations in this region adapted these new practices and carried out their activities. The results indicate a constant pattern of keeping animals throughout the study period. The principal component of the livestock diet consisted of Communicated by L. Vrydaghs. & Rosa Marı´a Albert [email protected]; [email protected] 1

IT622/13 Facultad de Letras, Departamento de Geografı´a, Prehistoria y Arqueologı´a, Universidad del Paı´s Vasco UPV/ EHU, Toma´s y Valiente s/n, 01007 Vitoria-Gasteiz, Spain

2

ERAAUB, Dept. d’Histo`ria i Arqueologia, Universitat de Barcelona, Montealegre 6-8, 08001 Barcelona, Spain

3

Catalan Institution for Research and Advanced Studies, ICREA, Pg. Lluı´s Companys 23, 08010 Barcelona, Spain

wild grasses from the vicinity. The presence of grass inflorescences suggests a diet rich in summer grass. In addition to grasses, dicotyledonous plants were also indicated, both through phytoliths and ash pseudomorphs. Faecal spherulites from herbivores were also noted in the samples and together with phytoliths and ash pseudomorphs they give important information regarding the formation processes of the studied deposits. Keywords Northern Iberian Peninsula
Fumier
Neolithic
Phytoliths
Spherulites
Ash pseudomorphs

Introduction Fumier deposits are the product of the recurrent use of caves and rock shelters for stabling livestock. These have been formed in the Mediterranean area since Neolithic times up to the Bronze Age; however they are scarce in or absent from Iron Age sites (Angelucci et al. 2009; Ferna´ndez-Eraso 2010). These kinds of deposits are generally located at medium altitudes up to 1,000 m a.s.l. Most commonly, the residues generated were periodically burnt in order to clean up the sites. As a result, a succession of different layers with varied colouration and texture was created, including a reddened layer at the base and a whitish ashy layer topping the sequence (Ferna´ndez-Eraso and Polo-Dı´az 2009; PoloDı´az 2009). Another characteristic of these deposits is the scarcity of artefacts within the archaeological assemblage (Angelucci et al. 2009; Ferna´ndez-Eraso and Polo-Dı´az 2009). The micromorphological studies of fumier deposits corresponding to the Neolithic period in the Mediterranean, e.g. Couleveiki Cave (Peloponnese, Greece), Arene Candide (Liguria, Italy), Riparo Gaban (Trento, Italy), El Mirador ´ lava, Spain) and Cueva del (Burgos, Spain), Los Husos II (A

123

144

Toro (Ma´laga, Spain) have provided much information regarding the first husbandry practices in southern Europe and their formation processes (Angelucci et al. 2009; Ferna´ndez-Eraso and Polo-Dı´az 2009; Ferna´ndez-Eraso 2002, 2008, 2010; Karkanas 2006; Polo-Dı´az and Ferna´ndez-Eraso 2010; Polo-Dı´az et al. 2014; Macphail et al. 1997; Verge`s et al. 2002; E´gu¨ez et al. 2014). In addition, and due to the scarcity of other archaeological remains, a multi-proxy approach combining analyses of phytoliths, spherulites and ash pseudomorphs has an important role, as they may provide important information on the types of activities carried out at these sites by Neolithic people, such as the use of plant resources, seasonality and livestock diet. Phytoliths are microscopic remains formed in living plants, which reproduce their cellular tissue and represent a valuable source of information from archaeological sediments to infer plant presence. Ash pseudomorphs are the product of burning bark, wood and leaves of dicotyledonous plants which are rich in calcium oxalate crystals. These calcium oxalate crystals transform into a more stable calcitic phase at temperatures between 400 and 500 C, but keeping their original habitus (shape) (Brochier and Thinon 2003; Canti 2003; Gur-Arieh et al. 2013; Shahack-Gross 2011). Their identification gives information on plants that have been burnt. Faecal spherulites are calcitic aggregations produced within the digestive systems of certain herbivores, especially ruminants such as sheep, goats and cattle. Their identification in soils and archaeological sediments may be indicative of animal presence (Albert et al. 2008; Shahack-Gross 2011; Shahack-Gross et al. 2003; Brochier et al. 1992; Canti 1997, 1998, 1999; Portillo et al. 2014). Integrated studies of phytoliths and faecal spherulites have been extensively applied to archaeological sites from the Near East to determine the presence of housed or penned animals and to define the use of the space at a site (Albert and Henry 2004; Albert et al. 2008; Portillo and Albert 2011, 2014; Portillo et al. 2014; Shahack-Gross et al. 2014; Elliott et al. 2014). They have also been employed in the study of fumier deposits from caves, yielding data about the formation processes of the sites and the use of plant resources for bedding and fodder (Cabanes et al. 2009; Alonso-Eguı´luz 2012). Nevertheless, there are very few studies where results from silica phytoliths and faecal spherulites have been combined with ash pseudomorphs (Gur-Arieh et al. 2013, 2014; PoloDı´az et al. 2016; Portillo et al. 2016) and none of them on the very rich Neolithic sites of the Iberian Peninsula and in particular those in the Ebro basin. This region is particularly important because it represents the main route by which the new productive system and ideas of early Neolithic populations spread from the Mediterranean area to the northern Iberian Peninsula and the western Pyrenees (Ferna´ndez-Eraso et al. 2015). Hence, this site is best suited to shed new light on

123

Veget Hist Archaeobot (2017) 26:143–157

the adaptation of stabling and husbandry practices, vegetation management and seasonality here. We present the results of the integrated study of phytoliths, faecal spherulites and ash pseudomorphs from Levels IV to IX, which date to the Neolithic period, thus they represent the whole of the Neolithic period. The results obtained have yielded new information about the way in which Neolithic populations used this site, and about seasonality and livestock diet.

The site of Los Husos II ´ lava, Los Husos II belongs to the municipality of Laguardia, A and is located in a rock shelter in conglomerate bedrock situated at 900 m a.s.l. in the Sierra de Cantabria, a mountain range in the upper Ebro basin (Fig. 1). This area is characterized by a Mediterranean climate. The entrance of the shelter, which faces south, is triangular in shape and the shelter has a depth of 17 m, width of 7 m and height of 16 m (Fig. 2). J.M. Apella´niz recognized the site of Los Husos II during the archaeological excavations in the nearby rock shelter of Los Husos I, between the late 1960s and early 1970s. During the summer of 2001, during the archaeological excavations at Los Husos I under the supervision of Javier Ferna´ndez-Eraso, a test excavation was done at Los Husos II, showing the existence of an important stratigraphic sequence there. The archaeological excavations were then carried out between 2003 and 2006 by digging out the stratigraphic sequence described in Table 1. Micromorphological analyses revealed that the stratigraphic sequence was a fumier deposit (PoloDı´az 2010), which was the first one to be discovered in the upper Ebro basin. The micromorphological analyses also revealed a domestic area located in the west zone of Level VI (Polo-Dı´az and Ferna´ndez-Eraso 2010). Seventeen 14C dates were obtained (Table 2), from the upper levels with Roman chronology, to the lower ones corresponding to the Neolithic period. In all cases dating was obtained from short-lived items such as animal bones. The results show that, together with the nearby site of Pen˜a Larga (Ferna´ndez-Eraso 2011), Los Husos II represents one of the earliest pieces of evidence for animal domestication in the Basque Country.

Materials and methods A total of 37 samples were collected from the south-eastern profile corresponding to Levels IV to IX (Fig. 3) in order to study the phytoliths, spherulites and ash pseudomorphs. Table 3 lists the samples analysed and main results obtained from the study. The selected study area complements previous micromorphological analyses carried out on Level VI, but from a different area (Polo-Dı´az 2010;

Veget Hist Archaeobot (2017) 26:143–157

145

Fig. 1 Location map of Los ´ lava) Husos II site (Laguardia, A

Fig. 2 Plan of the Los Husos II rock shelter and excavation area

Polo-Dı´az and Ferna´ndez-Eraso 2010). In addition, three control samples were collected from three different places outside the cave; two near the excavated area and a third one from the nearby woodland. Phytoliths were chemically extracted following the method proposed by Katz et al. (2010). Between 20 and 50 mg of dry sediment were weighed and carbonate minerals removed by adding 50 ll of 6 N HCl. Upon completion of the reaction 450 ll of sodium polytungstate solution [SPT,

Na6(H2W12O40)
H2O] with a density of 2.4 g/ml was added, vortexed, and agitated with ultrasound for 10 min. The samples were then centrifuged for 5 min at 5,000 rpm and the supernatant liquid was removed to another tube. 50 ll aliquots of the supernatant liquid were placed on microscope slides and covered by 24 9 24 mm cover slips. Phytoliths present in 20 visual fields at 2009 magnification were counted for phytolith quantification, and for morphological analysis a minimum of 200 different morphotypes at 4009 magnification were identified to obtain reliable data (Albert and Weiner 2001). Morphological identification of phytoliths was based on our own modern reference collection (Albert et al. 2011, 2016) (www.phytcore.org) as well as standard literature (Twiss 1969; Brown 1984; Mulholland and Rapp 1992; Piperno 2006). The nomenclature of the phytoliths followed, whenever possible, the International Code for Phytolith Nomenclature (ICPN) (Madella et al. 2005). Spherulites and ash pseudomorphs were extracted following Gur-Arieh et al. (2013). Between 10 and 50 mg of sediment were weighed and then sieved through a 150 lm sieve and placed in a 0.5 ml conical centrifuge tube. 500 ml of 2.4 g/ml SPT were added, the tubes were vortexed and then agitated with ultrasound for 10 min. The solution was vortexed again and 50 ll of the solution was placed on a microscope slide and covered with a 24 9 24 mm cover slip. Counting was performed using a polarized light microscope at 4009 magnification over 15 random fields across the slide. Gur-Arieh et al. (2014) used the ratio between ash pseudomorphs and spherulites (PSR) to identify sediment composition. This was based on the fact that wood does not contain spherulites and has low concentrations of phytoliths, while dung has a variable

123

146

Veget Hist Archaeobot (2017) 26:143–157

Table 1 Levels in the deposit of Los Husos II and description of the sediments Archaeological level

Thickness (cm)

Colour

Description

Superficial

10–13

5YR4/3, reddish brown

Silty clay sediment with many stone fragments and plenty of pieces of charcoal

I

12–29

10YR4/2, greyish brown

Sand abundant, stones, roots and charcoal fragments were also abundant

II

21–41

7.5R3/2, dark brown

Two sublevels were distinguished, divided by a board made of carbonized Fagus sylvatica (beech). The top was composed of silty clays and at the bottom the sediment was greyish

2.5Y2.5/1, black

Mass of black charcoal. Beneath it was a reddened sediment (10YR2.5/1). Soil with little fragments of charcoal and reddish sandstone affected by fire

5YR7/1, light grey

Secondary cremation hole made of whitish ash 17 cm thick which contained a large amount of charred human bones (Ferna´ndez-Eraso 2003)

Sublevel II inferior III

17

IV V

VI

Various layers of white ashes overlapping other black layers formed by charcoal, these overlying very thin layers of rubefied soil (Ferna´ndez-Eraso 2004) 40

25–35

10YR 2.5/1, reddish black 10YR3/2, greyish brown

Succession of brown and black layers that alternate with increasing depth. The sequence begins with a reddish black layer (10R2.5/1) that contained a large amount of small charcoal fragments. The layers that alternate with them were greyish brown (10YR3/2) (Ferna´ndez-Eraso 2005)

7.5YR5/3, brown

Loose soils together with another ashy layer, soft reddish brown (5YR6/4). In this level a hearth delimited by a stone circle was identified

VII

20–25

VIII

25

7.5YR6/6, reddish yellow

Sands, with pebbles and stone fragments. Archaeologically sterile

IX

6–8

7.5YR4/3, brown

Silty clay, with cobbles, small stone and charcoal fragments. (Ferna´ndez-Eraso 2006a, b)

7.5YR/6, reddish yellow

Corresponds with the base of the shelter and very similar to Layer VIII. Sands becoming darker and sandier with increasing depth. Archaeologically sterile and resting on the bedrock (Ferna´ndez-Eraso 2007)

X

Part of the same fumier of the previous and the next

amount of ash pseudomorphs but high concentrations of both spherulites and phytoliths. Their results showed that when the ratio is lower than 5, sediments are composed mainly of dung, whereas ratios greater than 5 denote wood composition. Following this model, we calculated the PSR in order to characterize the composition of each layer analysed (Table 3; Gur-Arieh et al. 2013). Melted phytoliths were identified in some of the samples. Silica is quite resistant to thermal distortion and it tends to melt at temperatures up to 1,000 C (Piperno 2006). Moreover, Gur-Arieh et al. (2014) point out that phytoliths melt when temperatures are higher than 700 C for a long period. Although the melting and weathering of phytoliths are two independent processes, some previous results have shown that phytoliths are more prone to dissolution when burnt (Cabanes et al. 2011). Thus taking into account the fact that weathering usually takes place immediately after deposition of phytoliths in soils and sediments (Karkanas et al. 2000, 2002) and that burnt phytoliths are more prone to dissolution, we conducted a Pearson correlation test to measure the incidence of burning over weathering, using SPSS software (Fig. 4). As the identification of melted phytoliths suggests temperatures higher than 850 C, another question relates to the effect of fire on spherulites and

123

ash pseudomorphs in those samples where the percentage of melted phytoliths was high. Thus the ratio between spherulites and melted phytoliths on the one hand (SMR), and ash pseudomorphs and melted phytoliths (PMR) on the other, has been calculated (Figs. 5a, b). In addition, Cabanes et al. (2009) point to a good correlation between spherulites and multicell structures in the samples from El Mirador. In order to check whether that correlation existed in our samples, a Pearson analysis was run over both variables, also using SPSS software (Fig. 6). Principal components analysis (PCA) was carried out for all the samples related to morphotypes, plant types and plant parts present at the site, in order to find out whether there was any pattern of phytolith presence throughout the sequence (Figs. 7a, b). The analyses were carried out using the OpenSource software R 3.2.3 version (https://www.rproject.org/) with the PCA statistical package.

Results Phytoliths, faecal spherulites and ash pseudomorphs were generally well represented in all the samples (Figs. 8a–c). Exceptions were Sample 1 (sterile sample) where only

Veget Hist Archaeobot (2017) 26:143–157 Table 2 List of Los Husos II

147

14

C dates for

Site

Level

Age (BP)

Age (cal

LH-II

I

1,610 ± 40

1,570–1,410

AD

380–540

Beta 208842

LH-II

I

1,570 ± 40

1,540–1,360

AD

410–580

Beta 208843

LH-II

II

1,370 ± 40

1,320–1,250

AD

620–700

Beta 208844

LH-II

II inf.

1,770 ± 50

1,820–1,550

AD

130–400

Beta 208845

LH-II

III

4,670 ± 50

5,580–5,520

3630–3570

Beta 208847

5,480–5,300

3540–3350

LH-II

IV

4,910 ± 60

5,740–5,580

3790–3630

Beta 208848

LH-II

IV inf.

4,930 ± 40

5,730–5,600

3780–3650

Beta 208849

LH-II

V

5,280 ± 40

6,180–5,930

4230–3980

Beta 208850

LH-II

V

5,300 ± 40

6,190–5,940

4240–3990

Beta 161184

LH-II

V

5,430 ± 60

6,310–6,100

4360–4150

Beta 161185

6,070–6,020

4120–4070

6,320–6,250

4370–4300

6,250–6,200

4300–4250

LH-II

V

5,490 ± 40

BP)

Age (BC)

Lab. code

Beta 208851

LH-II LH-II

VI VI

5,300 ± 40 5,520 ± 40

6,190–5,940 6,400–6,280

4240–3993 4450–4320

Beta 208852 Beta 208853

LH-II

VII

5,790 ± 40

6,670–6,680

4720–4530

Beta 221641

LH-II

VII

6,050 ± 40

6,990–6,770

5040–4820

Beta 221640

LH-II

VIII

6,040 ± 40

6,990–6,760

5040–4810

Beta 221642

LH-II

IX

7,360 ± 40

8,200–8,050

6250–6100

Beta 221643

Fig. 3 South profile of the Los Husos II site indicating sampling area

phytoliths were identified, Sample 15, which did not contain spherulites and Samples 22 and 24, which did not have ash pseudomorphs. Faecal spherulites and ash pseudomorphs were also absent from the three control samples from outside the shelter (Table 3). The estimated number of ash pseudomorphs per gram of sediment is commonly lower than that obtained from

experimental fire studies by Gur-Arieh et al. (2013), which yielded 7–17 million per g of fuel material. Again, Sample 1, which was archaeologically sterile, as well as Samples 22 and 24 did not contain ash pseudomorphs, which in the latter might be a result of temperatures having been lower than 450–500 C, which did not allow calcium oxalate crystals to change into calcite.

123

148

Veget Hist Archaeobot (2017) 26:143–157

Fig. 4 Pearson correlation test scatterplot of weathered morphotypes versus melted phytoliths. Note that samples are not distributed along the line, showing the lack of correlation between both types of microremains

Fig. 6 Pearson correlation test carried out on multicell structures and spherulites. Note that there is no correlation between rises in both variables, as samples are dispersed in the plot

Fig. 5 Ratio between spherulites (SMR) and ash pseudomorphs (PMR), compared to melted phytoliths. This ratio shows that as the number of melted phytoliths increases, the amount of spherulites and ash pseudomorphs decreases, indicating a direct effect of fire on the amounts of micro-remains. Note that samples with no reliable number of recognizable phytolith morphotypes have been included in the analysis

Fig. 7 Principal component analyses (PCA) plots run. a morphotypes; b plant parts and plant types. Sample numbers are coloured in relation to the level to which they correspond. Level IX, black; Level VIII, grey; Level VII, green; Level VI, blue; Level V, purple; Level IV, orange. Abbreviations correspond to the following morphotypes: ShC3 short cells rondels from C3, ShC4 short cells bilobates from C4, El elongate, LcW long cell wavy, LcE long cell echinate, LcD long cell dendritic, LcP long cell polylobate, LcV long cell verrucate, Bll bulliforms, Pl platelets, Pck prickle, Awn hair monocot, Sph spheroids, St stoma

123

Veget Hist Archaeobot (2017) 26:143–157

149

Fig. 8 Microphotographs of micro-remains taken at 4009 magnification a faecal spherulites under cross polarized light showing the characteristic extinction cross; b ash pseudomorphs under cross polarized light of the rhombohedral type formed in dicotyledonous plants; c ash pseudomorphs; d–e melted multicell structures; f long cell polylobate from leaves/stems of grasses; g short cell rondel from

C3 grasses of the Pooideae subfamily; h short cell trapezoid from C3 grasses of the Pooideae subfamily; i multicellular structure from leaves/stems of grasses, showing thermal alteration; j multicellular structure from husk phytoliths, formed by long cells echinate and papillae

The results from the PSR analyses, showing values of 0–5, indicate dung as the main component of the material in most of the samples. Only Sample 15 had a value higher than 5, which according to Gur-Arieh et al. (2014), indicates wood composition.

Regarding preservation, out of the 37 archaeological samples analysed, only Samples 1, 9, 11, 14, 15 and 19 had high percentages of weathered morphotypes, 25–40 % of the total, and up to 96 % in Sample 14 (Table 3). Sample 1 corresponded to a sterile level, and Samples 9, 14 and 15

123

150

Veget Hist Archaeobot (2017) 26:143–157

Table 3 The main results obtained from the study: estimated amounts of phytoliths, spherulites and ash pseudomorphs per gram of sediment in all the samples, as well as the ratios between ash pseudomorphs and spherulites (PSR values)

The table also shows the relative presence of weathered morphotypes and melted phytoliths; n. a.—not analysed

123

Veget Hist Archaeobot (2017) 26:143–157

were white ashy layers from Level VI. These three later samples could not be morphologically interpreted due to the small number of phytoliths identified (\70). On the other hand, Samples 11 and 19 corresponded to greyish sediments with dung as the main component (Table 3). Melted phytoliths were noted in some of the samples (Table 3; Figs. 8d, e). For example, in Samples 20, 21, 25 and 30 the percentage of melted phytoliths ranged between 20 and 28 % of the total counts. The results of the Pearson correlation test show that there is positive correlation between weathered and melted phytoliths (p = 0.01), although with an R squared value of 0.134, which indicates an influence of 13 % between them (Fig. 4). Nevertheless this percentage is too low to fully support a direct relationship between burnt phytoliths and an increase of weathering. Conversely, the PMR and SMR indices, which show the ratio between ash pseudomorphs and spherulites in relation

151

to melted phytoliths respectively, decrease as the percentage of melted phytoliths increases (Figs. 5a, b). The phytolith morphological analyses indicate that phytoliths from the Poaceae family (grasses) dominate all the sequence. This was expected, since grasses are the principal component of the diet of grazing animals (Albert et al. 2008; Portillo et al. 2014). The most common morphotypes recognized from this family were short cell rondel, prickles, papillae and long cells with decorated margins, mostly polylobate (Fig. 8f), wavy margins and echinate (Table 4). The presence of short cells can rise to 70 % and had a total average of 53 % (Table 4). This high percentage of short cells is probably due to the fact that these morphotypes are very resistant to taphonomic processes (Albert et al. 2006; Cabanes et al. 2011). The morphology of short cells has been shown to follow meaningful environmental traits allowing differentiation between C3 and C4 grasses (Twiss 1969; Piperno 2006),

Table 4 List of phytolith morphotypes identified in the Los Husos II samples and their plant attribution based on the reference collection and standard literature, along with the average abundance Phytolith morphotype

Plant attribution

Abundance (%)

Bulliform cuneiform

Grass leaves

Elongate psilate or rugulate

Monocotyledons

Elongate echinate

Monocots

Ellipsoid psilate or rugulate

Dicotyledon wood/bark

0.2

Hair monocot

Grass inflorescences

0.7

2.6 10 6.3

Hat shape

Cyperaceae

0.04

Hair base

Dicotyledon leaves

0.2

Irregular psilate or rugulate

Dicotyledons, wood/bark

0.7

Long cell dendritic

Grass inflorescences

0.6

Long cell echinate

Grass inflorescences

3

Long cell polylobate

Grass leaves

4

Long cell sinuous

Grass leaves

0.1

Long cell wavy

Grass leaves

4.7

Papillae

Grass inflorescences

4.6

Parallelepiped blocky psilate or rugulate Parallelepiped elongate psilate or rugulate

Dicotyledon wood/bark Monocotyledons

0.6 6.7

Parallelepiped thin psilate or rugulate

Monocotyledons

1.2

Platelet

Dicotyledon leaves

0.1

Prickle

Grass leaves

8.7

Short cell bilobate

Grasses

0.2

Short cell polylobate

Grasses

0.07

Short cell cross

Grasses

Short cell rondel

Grasses

0.01 53.8

Short cell rondel long (tower)

Grasses

0.07

Short cell trapeziform

Grasses

0.2

Spheroid psilate or rugulate (globular psilate or regulate ICPN)

Dicotyledon wood/bark

0.5

Stomata

Monocotyledons

0.07

Tracheary

Dicotyledon leaves

0.07

123

152

which subsequently permits inference of various climatic conditions. In our samples, most of the morphotypes identified corresponded to rondels and trapeziforms, whereas bilobate morphotypes were noted in very small amounts (Table 4). Short cell rondels and trapeziforms (Figs. 8g, h) such as the ones identified at Los Husos II are related to the C3 Pooid subfamily, which grow in high latitudes and/or highlands and are indicative of temperate and moist climates (Twiss 1992). Morphotypes related to other monocotyledons were scarce to absent, such as hatshaped phytoliths diagnostic of the Cyperaceae subfamily (0.06 % average) (Table 4). In relation to the anatomical origin of plants, phytoliths from the inflorescences of the Poaceae family, represented by papillae, long cells echinate and dendritic were commonly identified in most of the samples. The greatest presence of phytoliths from inflorescences corresponded to Samples 32 and 34 with 20 and 25 % (Fig. 9a). Nevertheless, their presence increased towards the uppermost samples, reaching its maximum in Samples 22–37,

Veget Hist Archaeobot (2017) 26:143–157

corresponding to the Upper Neolithic in the upper part of the stratigraphic sequence (Fig. 9b). Dendritic morphotypes, which have been traditionally associated with domestic crops and high water availability (Jenkins et al. 2011a, b; Albert et al. 2008; Ball et al. 1999; Rosen and Weiner 1994), were scarce in our samples (0.6 % average) (Table 4). Multicell structures, the epidermal silicified tissues of grasses (Rosen 1992; Roberts and Rosen 2009), were identified throughout all the sequence, with the only exception of Samples 1 and 19, although their relative presence does not exceed 8 %. However, their occurrence increases from Sample 21 to the uppermost Sample 37, which correspond to the Upper Neolithic. The multicell structures identified correspond to leaves/stems of grasses (Fig. 8i) and very small amounts corresponded to the husks of the same plants (Fig. 8j), between 0.5 and 1.5 %. In addition, Pearson correlation carried out on the amounts of multicell structures and spherulites shows no correlation between both variables (p = 0.071; squared R: 0.005) (Fig. 6). Finally, phytoliths characteristic of dicotyledonous plants were also noted in the samples, although in lesser amounts (Table 4). Within this group, phytoliths from the wood and bark were more abundant than those from leaves, as they are more resistant than the latter, although produced in smaller amounts (Albert and Weiner 2001; Tsartsidou et al. 2007). The principal components analysis (PCA) of the most common phytolith morphotypes identified shows that the two principal morphotypes forming the phytolith assemblage are short cells rondel and elongates, while other morphotypes found in the middle part of the plot are not so relevant (Table 4). At the same time the differences between variables are low and vectors do not show correlation between them (Fig. 7a). On the other hand, there seems to be no grouping pattern within samples, whereas samples from Level IV are close together. Additionally, PCA of plant composition points to two major components, with inflorescences and leaf stems from grasses, as expected (Fig. 7b). Yet the plots show the same tendencies, with low variability, no correlation between variables and no pattern between samples, but grouping of samples from Level IV, in this case around the inflorescences variable.

Discussion

Fig. 9 Histogram showing inflorescence presence in the sequence. a percentage of inflorescences per sample; b percentage average of inflorescences per level. Error bars indicate 1r standard deviation

123

Consistently with previous micromorphological analyses and archaeological studies of these levels in other areas of the site (Ferna´ndez-Eraso and Polo-Dı´az 2009; Polo-Dı´az and Ferna´ndez-Eraso 2010), our results confirm that in most cases the associated presence of phytoliths and faecal

Veget Hist Archaeobot (2017) 26:143–157

spherulites is the result of dung accumulation as the result of keeping livestock in the cave (Table 3). Moreover, the constant presence of ash pseudomorphs in most of the samples indicates that these sediments were burnt. These results are also consistent with micromorphological analyses, which indicate that the place was used as a stable and periodically burnt to clean it up and to reduce the volume of dung accumulations (Polo-Dı´az 2010). There are nevertheless some exceptions to this general interpretation, as in Sample 15. Here, the microarchaeological composition differs by having large amounts of ash pseudomorphs, a small amount of phytoliths and an absence of faecal spherulites (Table 3). The PSR index indicates that this particular layer corresponds to wood ash, and thus it represents the only example of a complete burning episode in this area, but not the only one, since more complete burning episodes have been detected in other areas of the deposit (Polo-Dı´az 2010). The identification of wood ash may be interpreted as the result of the use of wood as fuel for the fire. Other possible uses may also be related to its use for penning, as proposed in other burning episodes from Los Husos as well as from other fumier deposits at other sites such as Arene Candide or Kouveleiki (Macphail et al. 1997; Karkanas 2006; Ferna´ndez-Eraso and Polo-Dı´az 2009). Ashes are more in contact with the surface, so unless there was a rapid sedimentation, which seems to be the case here, they are the first to receive the effect of natural bioturbations or human activities such as sweeping that can make them disappear, and so they are not always preserved (Mallol et al. 2013). The combined presence of silica phytoliths, which preserve well in sediments with a pH less than 8, together with calcitic microremains, both spherulites and ash pseudomorphs, which tend to dissolve in acidic conditions (Canti 1999; Gur-Arieh et al. 2014), reveals that the sediments in those samples where the three types of remains have been recovered were not severely affected by post-depositional processes and have remained in their original state. The small amount of phytoliths recovered from the ashy Layers 9 and 14, and the abundance of ash pseudomorphs is related to a greater presence of wood in the samples. Previous studies by Portillo et al. (2012) indicated that ovicaprines and cattle produce 541 and 235 million spherulites respectively per gram of dung. These data are not consistent with ours, as the amount of spherulites recovered did not exceed 33 million per gram of sediment (Table 3). On the other hand, micromorphological analyses point to the presence of ovicaprines and cattle at the site, the first ones being more abundant (Ferna´ndez-Eraso 2008; Polo-Dı´az and Ferna´ndez-Eraso 2008). Thus the initial spherulite input should have been richer, but would have decreased due to the effects of fire. Moreover, there are differences in the amounts of spherulites within samples,

153

probably due to post-depositional processes. The occurrence of ash pseudomorphs derived from calcium oxalate crystals indicates that these sediments were burnt at temperatures of 400–500 C (Brochier and Thinon 2003), or higher. However Samples 20, 21, 25 and 30 had melted phytoliths in more 20 % of them and were associated with spherulites and ash pseudomorphs. According to Gur-Arieh et al. (2014), the presence of melted phytoliths indicates temperatures above 700 C for a long period. Under these conditions though, the spherulites and ash pseudomorphs should not have been preserved, because temperatures above 700 C for a long period result in the decomposition of ash pseudomorphs and spherulites (Shahack-Gross 2011; Gur-Arieh et al. 2014). Recent experiments carried out by Verge`s (2011) and Verge`s et al. (2016) state that temperatures within these dung deposits depend on several factors. For example, the porosity of the material, the higher the porosity the higher the temperature, as voids within the structure allow oxygen circulation, raising the temperature. The state of preservation of dung is also a factor, as the more degraded it is, the lower the temperature reached. Climatic agents such as wind also play a role in increasing the heat. In any case, the maximum temperature varies between 600 and 800 C and can last for several days (Verge`s et al. 2016). Therefore the temperatures generated in archaeological sediments could vary between different burning episodes generating heterogeneous temperatures. In our samples, the PMR and SMR indices showing the ratio between spherulites and ash pseudomorphs in relation to melted phytoliths indicate that high temperature had an effect on spherulite and ash pseudomorph concentrations, decreasing their number (Figs. 5a, b). However, this temperature would have not been high enough and not evenly distributed in all areas to completely dissolve these microremains. Also in relation to spherulite preservation, previous studies by Cabanes et al. (2009) show that reworking affects both the preservation of spherulites and phytolith-multicell structures. Nevertheless, although accepting some dissolution of faecal spherulites, their general presence in samples which have been defined as dung accumulations reworked by piling up before cleaning up the site (Polo-Dı´az 2010), does not seem to fully support the Cabanes hypothesis. Reasons for this better preservation at Los Husos need to be further explored. Regarding phytoliths, exceptions to the generally good preservation were Samples 9 and 14, with 88 and 96 % dissolution respectively. This increase in phytolith dissolution may be related to more alkaline conditions (pH [ 8.5) for these particular samples. When calcitic sediments are in contact with water, the pH is buffered to more alkaline values at which silica phytoliths tend to dissolve (Weiner 2010), whereas ash pseudomorphs and

123

154

spherulites remain. This is consistent with the high occurrence of ash pseudomorphs noted in these samples. The results of the correlation test also show that melting of phytoliths and weathering are not directly related (Fig. 4). Conversely, these are the products of two different and not mutually exclusive processes that can coexist within the same deposit. According to Cabanes et al. (2011), weathering has more effect on burnt phytoliths. This might indicate that the dung was burnt immediately before further use of the rock shelter, and thus the burnt heap would have been rapidly covered by a new episode that protected it from taphonomic processes. Micromorphological analyses support this hypothesis, although the fires were started periodically and not before each use (Polo-Dı´az et al. 2016; Polo-Dı´az 2010). The associated results from faecal spherulites produced in the digestive systems of ruminants and from phytoliths, indicate that a large percentage of the latter are the product of animal diet (Portillo et al. 2012, 2014). On the other hand, the large numbers of both types of microremains contrast with the small number of phytoliths and the absence of spherulites and ash pseudomorphs in the control samples from outside the shelter (Table 3). Regarding the plant composition, grasses are constantly present in the samples. The almost exclusive dominance of short cell rondels along with short cell trapezoids from the Poaceae family (Table 4) indicates a major presence of plants from the C3 Pooideae subfamily, which does not differ from the vegetation presently found in this area and which consists of Mediterranean woodland and wild grasses such as Poa bulbosa (Pooideae). The evidence of inflorescences which are well represented at the site (up to 25 %), indicates that the site was in use during spring and summer (Figs. 9a, b). This seasonal use makes sense, as winters are cold and the weather gets better in summer, providing a more comfortable shelter. Furthermore, the keeping of the livestock in the rock shelter during the spring and summer would have prevented their access to the growing crops. Although it is thought that the village in which these Neolithic people lived would have been near the dolmens down on the plain at 400 to 700 m a.s.l., and thus far away from Los Husos, there is no consistent evidence of its precise location (Ferna´ndez-Eraso and Mujika-Alustiza 2013). The larger amounts of inflorescence morphotypes in the uppermost samples, mostly long cells echinate, together with the larger amounts of multicells in Level IV, could be due to better preservation of this level (Cabanes et al. 2011). Another possibility is that this area could have been the boundary of a dumping area, thus waste from other domestic activities might be present in these samples. However, micromorphological analyses should be carried out in this area in order to confirm or discard this hypothesis.

123

Veget Hist Archaeobot (2017) 26:143–157

The incidence of multicell structures at the site is low (3 % average) when compared to Portillo et al. (2012), where dung cakes preserved these structures in large amounts, close to 18 % of relative presence. In addition, dendritic phytoliths, which are more abundant in crops, were also noted in small numbers (0.6 % average) (Albert et al. 2008; Ball et al. 1999). This lower percentage of multicell structures and dendritic phytoliths was also noted in the nearby fumier at San Cristo´bal (Alonso-Eguı´luz 2012; Polo-Dı´az et al. 2016). According to Rosen and Weiner (1994), multicell phytoliths are more abundant in irrigated crops, and this, along with the small presence of dendritic phytoliths which are also abundant in crops, suggests that the plants represented at the site were wild grasses. In addition to wild grasses, dicotyledonous plants would also have been part of the diet of the livestock, as shown by the identification of ash pseudomorphs and dicotyledonous phytoliths. In addition, micromorphological analyses have pointed out the presence of oxalate crystals within dung (Polo-Dı´az 2009; Polo-Dı´az and Ferna´ndez-Eraso 2008, 2010). These results are consistent with other studies, which show that goats eat leaves, even bark, from dicotyledons (Badal 1999; Badal and Atienza 2005). Moreover, there are sites where fodder with dicotyledons has been detected (Rasmussen 1993). The overwhelming presence of rhombohedral morphotypes (Figs. 8b, c) in the ash pseudomorphs records is in agreement with the archaeobotanical data from charcoal remains, which showed the presence of deciduous Quercus (Ruiz-Alonso 2014). Quercus taxa are rich calcium oxalate producers and the main morphotypes they produce are rhombohedrals (Gur-Arieh et al. 2013), similar to the ones identified in our samples. Charcoal analyses have also identified the presence of Taxus baccata (yew) at the site (Ruiz-Alonso 2014). Despite the fact that some authors point out the presence of calcium oxalate crystals mostly of tetragonal prism types in the genus Taxus (Dickson 2000; Hudgins et al. 2003), these morphotypes have not been identified in our samples. The statistical results do not show significant differences in plant composition between samples. Hence it can be suggested that the diet of the livestock was not of specific plants, but rather used the vegetation around the site. This use of nearby vegetation is also noted from phytolith analyses from the Neolithic archaeological site of Els Trocs (Lancelotti et al. 2014). Similarly, the results from Los Husos II and the lack of evidence of crop plants suggests a well-established pattern based on livestock allowed to graze freely around the site during the day and then kept inside the cave at night, instead of bringing crops or secondary by-products to the site as fodder. This lack of crops has been also pointed out

Veget Hist Archaeobot (2017) 26:143–157

in the nearby site of San Cristo´bal, for the later Chalcolithic period (Polo-Dı´az et al. 2016; Alonso-Eguı´luz 2012). The use of a shelter for keeping livestock would have been seasonal; hence from late summer to the following spring the livestock might have been kept inside or near the village. In view of the similar results obtained from Los Husos II as well as from San Cristo´bal and Els Trocs (Alonso-Eguı´luz 2012; Lancelotti et al. 2014), this herding activity must be understood as a recurrent practice and not as something isolated and/or an auxiliary type of livestock practice. The prospective results from the study of the nearby Neolithic walled village of Los Cascajos (Los Arcos, Navarra), where husbandry activities have been indicated in two areas inside the precinct, will surely improve our knowledge of these related activities carried out inside villages in comparison to those in caves and shelters. An experimental piece of work carried out by Verge`s et al. (2016) shows that in the pen at Mas del Pepet (Catalonia), livestock were stabled during the night and grazed freely all around during the day; this practice took place mostly during April/May until October/November. The shelter of Los Husos II is one of many caves that, since the beginning of Neolithic times, were in use throughout the Mediterranean area to the interior of the Iberian Peninsula. The beginning of those new activities coincided with the last cold fluctuation of the 8,200 BP event, followed by climate amelioration with moderately cold winters and dry summers, allowing formation of the Mediterranean woodland that persists until nowadays. This climate amelioration would have permitted the establishment, development and expansion of these farming practices.

Conclusions The high concentrations of phytoliths, spherulites and ash pseudomorphs confirm the stability of the deposit throughout the levels studied. The results show that the sediments consisted mainly of dung, with few exceptions such as Sample 15, corresponding to the wood used to start the fire. The effect of fire is evident as melted phytoliths appear in some samples and, although it did not significantly affect the presence of spherulites and ash pseudomorphs, the amounts of both microremains decrease. The livestock would have consisted of mainly sheep and/or goats with some cattle, as indicated by micromorphological analyses and zooarchaeological assemblages. The small amounts of multicell and dendritic morphotypes which are common in crops indicate the grazing of wild grasses growing around the site, as cultivated fields with crops were probably located far away from this site.

155

Additionally, the presence of flowering parts of the plants shows that these stabling practices took place from late spring to summer, when grasses flourish. In addition to grasses, dicotyledonous plants would have been consumed as well by the herd, including probably Quercus. In sum, the results demonstrate the survival of a very well established livestock practice, where the herd would have been moved to higher areas to feed on wild grasses and bushes during the season when crops were growing in the cultivated fields close to the village. This pattern would have started in the early Neolithic and continued through Neolithic times, at a time of climate amelioration in this area. Acknowledgments This work is part of the Research Group IT62213. Financial support came from the Spanish Ministry of Science and Innovation (HAR2010-15967, HAR2013-42054-P) as well as from AGAUR from the Catalan Government SGR for ERAAUB Consolidated Group (2014 SGR 845). M.A.E thanks to A. Ramirez and M. Catalina their comments on the English version, and also to A. Angourakis for his advices on statistics. This work is dedicated to the memory of Lydia Zapata.

References Albert RM, Henry DO (2004) Herding and agricultural activities at the early Neolithic site of Ayn Abu Nukhala (Wadi Rum, Jordan). The results of phytolith and spherulite analyses. Pale´orient 30(2):81–92 Albert RM, Weiner S (2001) Study of phytoliths in prehistoric ash layers using a quantitative approach. In: Meunier JD, Colin F (eds) Phytoliths: applications in earth sciences and human history. Balkema, Lisse, pp 251–266 Albert RM, Bamford MK, Cabanes D (2006) Taphonomy of phytoliths and macroplants in different soils from Olduvai Gorge (Tanzania) and the application to Plio-Pleistocene palaeoanthropological samples. Quat Int 148:78–94 Albert RM, Shahack-Gross R, Cabanes D, Gilboa A, Lev-Yadun S, Portillo M, Sharon I, Boaretto E, Weiner S (2008) Phytolith-rich layers from the Late Bronze and Iron Ages at Tel Dor (Israel): mode of formation and archaeological significance. J Archaeol Sci 35:57–75 Albert RM, Esteve X, Portillo M, Rodrı´guez-Cintas A, Cabanes D, Esteban I, Herna´ndez F (2011) Phytolith CoRe, Phytolith Reference Collection. http://phytcore.org. Accessed April 2013 Albert RM, Ruı´z JA, Sans A (2016) PhytCore ODB: a new tool to improve efficiency in the management and exchange of information on phytoliths. J Archaeol Sci 68:98–105 Alonso-Eguı´luz M (2012) Estudio de los fitolitos en conjuntos de la Prehistoria reciente en la Sierra de Cantabria. El caso de los ´ lava). CKQ 2:1–14 niveles de redil de San Cristo´bal (Laguardia, A Angelucci DE, Boschian G, Fontanals M, Pedrotti A, Verge`s JM (2009) Shepherds and karst: the use of caves and rock-shelters in the Mediterranean region during the Neolithic. World Archaeol 41:191–214 Badal E (1999) El potencial pecuario de la vegetacion Mediterranea: Las Cuevas Redil. Saguntum Extra 2:69–75 Badal E, Atienza V (2005) Ana´lisis microsco´pico de coprolitos de herbı´voros hallados en contextos arqueolo´gicos. In: Molera i Marimon J, Farjas i Silva J, Roura i Grabulosa P, Pradell i Cara T (eds) VI Congreso Ibe´rico de Arqueometrı´a. Universitat i Futur, Girona, pp 283–293

123

156 Ball TB, Gardner JS, Anderson N (1999) Identifying inflorescence phytoliths from selected species of wheat (Triticum monococcum, T. dicoccon, T. dicoccoides and T. aestivum) and barley (Hordeum vulgare and H. spontaneum)(Gramineae). Am J Bot 86:1,615–1,623 Brochier JE, Thinon M (2003) Calcite crystals, starch grains aggregates or…POCC? Comment on ‘‘calcite crystals inside archaeological plant tissues’’. J Archaeol Sci 30:1,211–1,214 Brochier JE, Villa P, Giacomarra M, Tagliacozzo A (1992) Shepherds and sediments: geo-ethnoarchaeology of pastoral sites. J Anthropol Archaeol 11:47–102 Brown DA (1984) Prospects and limits of a phytolith key for grasses in the central United States. J Archaeol Sci 11:345–368 Cabanes D, Burjachs F, Expo´sito I, Rodrı´guez A, Allue´ E, Euba I, Verge`s JM (2009) Formation processes through archaeobotanical remains: the case of the Bronze Age levels in El Mirador cave, Sierra de Atapuerca, Spain. Quat Int 193:160–173 Cabanes D, Weiner S, Shahack-Gross R (2011) Stability of phytoliths in the archaeological record: a dissolution study of modern and fossil phytoliths. J Archaeol Sci 38:2,480–2,490 Canti MG (1997) An investigation of microscopic calcareous spherulites from herbivore dung. J Archaeol Sci 24:219–231 Canti MG (1998) The micromorphological identification of faecal spherulites from archaeological and modern materials. J Archaeol Sci 25:435–444 Canti MG (1999) The production and preservation of faecal spherulites: animals, environment and taphonomy. J Archaeol Sci 26:251–258 Canti MG (2003) Aspects of the chemical and microscopic characteristics of plant ashes found in archaeological soils. Catena 54:339–361 Dickson WC (2000) Integrative plant anatomy. Academic Press, Harcourt E´gu¨ez N, Mallol C, Martı´n-Socas D, Camalich MD (2014) Radiometric dates and micromorphological evidence for synchronous domestic activity and sheep penning in a Neolithic cave: Cueva de El Toro (Ma´laga, Antequera, Spain). Archaeol Anthropol Sci 8:107–123 Elliott S, Bendrey R, Whitlam J, Aziz KR, Evans J (2014) Preliminary ethnoarchaeological research on modern animal husbandry in Bestansur, Iraqi Kurdistan: integrating animal, plant and environmental data. Environ Archaeol 20:238–303 Ferna´ndez-Eraso J, Mujika-Alustiza JA (2013) La estacio´n megalı´tica de la Rioja Alavesa: cronologı´a, orı´genes y ciclos de utilizacio´n. Zephyrus 71:89–106 Ferna´ndez-Eraso J (2002) Niveles calcolı´ticos de corral en la Rioja Alavesa. Krei 6:3–13 Ferna´ndez-Eraso J (2004) Abrigo de Los Husos II. Arkeoikuska’03: 65–68 Ferna´ndez-Eraso J (2005) Abrigo de Los Husos II. Arkeoikuska’04: 59–62 Ferna´ndez-Eraso J (2006a) Abrigo de Los Husos II. Arkeoikuska’05: 45–50 Ferna´ndez-Eraso J (2006b) Establos de cronologı´a neolı´tica en la Rioja Alavesa. In: Herna´ndez Pe´rez MS, Soler Dı´az JA, Lo´pez Padilla JA (eds) IV Congreso del Neolı´tico Peninsular, vol I. Museo de Arqueologı´a de Alicante, Alicante, pp 361–367 Ferna´ndez-Eraso J (2007) Abrigo de Los Husos II. Arkeoikuska’06: 74–80 Ferna´ndez-Eraso J (2008) La secuencia del Neolı´tico en la Rioja Alavesa desde su origen hasta las primeras edades del metal. Veleia 24–25:669–687 Ferna´ndez-Eraso J (2010) La actividad pecuaria en la Rioja Alavesa durante la Prehistoria Reciente. Cuadernos de Arqueologia de La Universidad de Navarra 18:159–171

123

Veget Hist Archaeobot (2017) 26:143–157 Ferna´ndez-Eraso J (2011) Las cera´micas neolı´ticas de la Rioja Alavesa en su contexto: los casos de Pen˜a Larga y Los Husos I y II. In: Bernabeu Auban J, Rojo Guerra MA, Molina Balaguer LL (eds) Las primeras producciones cera´micas: el VI milenio cal a.C en la Penı´nsula Ibe´rica. Saguntum Extra 12, Valencia, pp 117–130 Ferna´ndez-Eraso J, Polo-Dı´az A (2009) Establos en abrigos bajo roca de la Prehistoria Reciente: su formacio´n, caracterizacio´n y proceso de estudio. Los casos de Los Husos y de San Cristo´bal. Krei 10:39–51 Ferna´ndez-Eraso J, Mujika-Alustiza JA, Zapata-Pen˜a L, IriarteChiapusso MJ, Polo-Dı´az A, Castan˜os P, Tarrin˜o-Vinagre A, Cardoso S, Sesma-Sesma J, Garcı´a-Gazolaz J (2015) Beginnings, settlement and consolidation of the production economy in the Basque region. Quat Int 364:162–171 Gur-Arieh S, Mintz E, Boaretto E, Shahack-Gross R (2013) An ethnoarchaeological study of cooking installations in rural Uzbekistan: development of a new method for identification of fuel sources. J Archaeol Sci 40:4,331–4,347 Gur-Arieh S, Shahack-Gross R, Maeir AM, Lehmann G, Hitchcock LA, Boaretto E (2014) The taphonomy and preservation of wood and dung ashes found in archaeological cooking installations: case studies from Iron Age Israel. J Archaeol Sci 46:50–67 Hudgins JW, Krekling T, Franceschi VR (2003) Distribution of calcium oxalate crystals in the secondary phloem of conifers: a constitutive defence mechanism? New Phytol 159:677–690 Jenkins E, Baker A, Elliott S (2011a) Past plant use in Jordan as revealed by archaeological and ethnoarchaeological phytolith signatures. In: Mithen S, Black E (eds) Water, life and civilisation: climate, environment and society in the Jordan valley. Cambridge University Press, Cambridge, pp 381–400 Jenkins E, Jamjoum K, Nuimat SA (2011b) Irrigation and phytolith formation: an experimental study. In: Mithen S, Black E (eds) Water, life and civilisation: climate, environment and society in the Jordan valley. Cambridge University Press, Cambridge, pp 347–372 Karkanas P (2006) Late Neolithic household activities in marginal areas: the micromorphological evidence from the Kouveleiki caves, Peloponnese, Greece. J Archaeol Sci 33:1,628–1,641 Karkanas P, Bar-Yosef O, Goldberg P, Weiner S (2000) Diagenesis in prehistoric caves: the use of minerals that form in situ to assess the completeness of the archaeological record. J Archaeol Sci 27:915–929 Karkanas P, Rigaud JP, Simek JF, Albert RM, Weiner S (2002) Ash bones and guano: a study of the minerals and phytoliths in the sediments of Grotte XVI, Dordogne, France. J Archaeol Sci 29:721–732 Katz O, Cabanes D, Weiner S, Maeir AM, Boaretto E, Shahack-Gross R (2010) Rapid phytolith extraction for analysis of phytolith concentrations and assemblages during an excavation: an application at Tell es-Safi/Gath, Israel. J Archaeol Sci 37:1,557–1,563 Lancelotti C, Balbo AL, Madella M, Iriarte E, Rojo-Guerra M, Royo JI, Tejedor C, Garrido R, Garcı´a I, Arcusa H, Pe´rez-Jorda´ G, Pen˜a-Chocarro L (2014) The missing crop: investigating the use of grasses at Els Trocs, a Neolithic cave site in the Pyrenees (1564 masl). J Archaeol Sci 42:456–466 Macphail R, Courty MA, Hather J, Wattez J (1997) The soil micromorphological evidence of domestic occupation and stabling activities. In: Maggi R (ed) Arene Candide: a functional and environmental assessment of the Holocene sequence (excavations Bernarbo’ Brea-Cardini 1940-50). Il Calamo, Roma, pp 53–88 Madella M, Alexandre A, Ball T (2005) International code for phytolith nomenclature 1.0. Ann Bot 96:253–260

Veget Hist Archaeobot (2017) 26:143–157 Mallol C, Herna´ndez CM, Cabanes D, Sistiaga A, Machado J, Rodrı´guez A, Pe´rez L, Galva´n B (2013) The black layer of Middle Palaeolithic combustion structures. Interpretation and archaeostratigraphic implications. J Archaeol Sci 40:2,515–2,537 Mulholland SC, Rapp G Jr (1992) A morphological classification of grass silica bodies. In: Rapp G Jr, Mulholland SC (eds) Phytolith systematics: emerging issues. Plenum Press, New York, pp 65–89 Piperno D (2006) Phytoliths: a comprehensive guide for archaeologist and paleoecologists. Altamira Press, Lanham Polo-Dı´az A (2009) Evidence of successive stabling episodes during Neolithic by microstratigraphy and micromorphology: the rockshelter of Los Husos II (Upper Ebro Basin, Spain). Frankfurter geowiss Arb Ser D Phys Geogr 30:99–109 Polo-Dı´az A (2010) Rediles prehisto´ricos y uso del espacio ganadero en abrigos bajo roca en la Cuenca alta del Ebro: geoarqueologı´a y procesos de formacio´n durante el Holoceno. Unpubl doctoral thesis, University of Basque Country Polo-Dı´az A, Ferna´ndez-Eraso J (2008) Aportacio´n de la micromorfologı´a a la determinacio´n de los rediles prehisto´ricos en el Alto Valle del Ebro: el caso del Neolı´tico de los Husos II (Elvillar, ´ lava). Cuaternanio Y Geoarqueologı´a 22:159–171 A Polo-Dı´az A, Ferna´ndez-Eraso J (2010) Same anthropogenic activity, different taphonomic processes: a comparison of deposits from Los Husos I & II (Upper Ebro Basin, Spain). Quat Int 214:82–97 Polo-Dı´az A, Martı´nez-Moreno J, Benito-Calvo A, Mora R (2014) Prehistoric herding facilities: site formation processes and archaeological dynamics in Cova Gran de Santa Linya (Southeastern Prepyrenees, Iberia). J Archaeol Sci 41:784–800 Polo-Dı´az A, Alonso-Eguı´luz M, Ruiz M, Pe´rez S, Mujika JA, Albert RM, Ferna´ndez-Eraso J (2016) Management of residues and natural resources at San Cristo´bal rock-shelter: contribution to the characterization of Chalcolithic agropastoral groups in the Iberian Penisnula. Quat Int 414:202–225 Portillo M, Albert RM (2011) Husbandry practices and livestock dung at the Numidian site of Althiburos (el Me´de´ina, Kef Governorate, northern Tunisia): the phytolith and spherulite evidence. J Archaeol Sci 38:3,224–3,233 Portillo M, Albert RM (2014) Early crop cultivation and caprine herding: the evidence from phytolith and faecal spherulite studies. In: Henry DO, Beaver EJ (eds) The sands of time: the desert Neolithic settlement of Ayn Abu Nukhayla. Bibliotheca Neolithica Asiae Meridionalis et Occidentalis, Ex Oriente, Berlin, pp 121–137 Portillo M, Valenzuela S, Albert RM (2012) Domestic patterns in the Numidian site of Althiburos (northern Tunisia): the results from a combined study of animal bones, dung and plant remains. Quat Int 275:84–96 Portillo M, Kadowaki S, Nishiaki Y, Albert RM (2014) Early Neolithic household behavior at Tell Seker al-Aheimar (Upper Khabur, Syria): a comparison to ethnoarchaeological study of phytoliths and dung spherulites. J Archaeol Sci 42:107–118 Portillo M, Belarte MC, Ramon J, Kallala N, Sanmartı´ J, Albert RM (2016) An ethnoarchaeological study of livestock dung fuels

157 from cooking installations in northern Tunisia. Quat Int. doi:10. 1016/j.quaint.2015.12.040 Rasmussen P (1993) Analysis of goat/sheep faeces from Egolzwil 3, Switzerland: evidence for branch and twig foddering of livestock in the Neolithic. J Archaeol Sci 20:479–502 Roberts N, Rosen A (2009) Diversity and complexity in early farming communities of southwest Asia: new insights into the economic and environmental basis of Neolithic C¸atalho¨yu¨k. Curr Anthropol 50:393–402 Rosen AM (1992) Preliminary identification of silica skeletons from Near Eastern archaeological sites: an anatomical approach. In: Rapp G Jr, Mulholland S (eds) Phytoliths systematics: emerging issues. Plenum Press, New York, pp 129–147 Rosen AM, Weiner S (1994) Identifying ancient irrigation: a new method using opaline phytoliths from emmer wheat. J Archaeol Sci 21:125–132 Ruiz-Alonso M (2014) Evolucio´n y explotacio´n de los recursos vegetales desde el Tardiglaciar en la vertiente mediterra´nea del Paı´s Vasco: datos antracolo´gicos. Unpubl doctoral thesis, University of Basque Country Shahack-Gross R (2011) Herbivorous livestock dung: formation, taphonomy, methods for identification, and archaeological significance. J Archaeol Sci 38:205–218 Shahack-Gross R, Marshall F, Weiner S (2003) Geo-ethnoarchaeology of pastoral sites: the identification of livestock enclosures in abandoned Maasai settlements. J Archaeol Sci 30:439–459 Shahack-Gross R, Boaretto E, Cabanes D, Katz O, Finkelstein I (2014) Subsistence economy in the Negev Highlands: the Iron Age and the Byzantine/Early Islamic period. Levant 46:98–117 Tsartsidou G, Lev-Yadun S, Albert RM, Miller-Rosen A, Efstratiou N, Weiner S (2007) The phytolith archaeological record: strengths and weaknesses evaluated based on a quantitative modern reference collection from Greece. J Archaeol Sci 34:1,262–1,275 Twiss PC (1969) Morphological classification of grass phytoliths. Soil Sci Soc Am Proc 33:109–115 Twiss PC (1992) Predicted world distribution of C3 and C4 grass phytoliths. In: Rapp G Jr, Mulholland SC (eds) Phytolith systematics: emerging issues. Plenum Press, New York, pp 113–128 Verge`s JM (2011) La combustio´n del estie´rcol: aproximacio´n experimental a la quema en monto´n de los residuos de redil. In: Morgado A, Baena J, Garcı´a D (eds) II Congreso Internacional de Arqueologı´a Experimental: abstracts. Ronda, pp 73–75 Verge`s JM, Allue´ E, Angelucci DE, Cebria` A, Dı´ez C, Fontanals M, Manyano´s A, Montero S, Moral S, Vaquero M, Zaragoza J (2002) La sierra de Atapuerca durante el Holoceno: datos premilinares sobre las ocupaciones de la Edad del Bronce en la cueva de El Mirador. Trabajos de Prehistoria 59:107–126 Verge`s JM, Burguet-Coca A, Allue´ E, Expo´sito I, Guardiola M, Martı´n P, Morales JI, Burjachs F, Cabanes D, Carrancho A, Vallverdu´ J (2016) The Mas del Pepet experimental programme for the study of prehistoric livestock practices: preliminary data from dung burning. Quat Int 414:304–315 Weiner S (2010) Microarchaeology: beyond the visible archaeological record. Cambridge University Press, Cambridge

123