Depto. de Prehistoria, Historia Antigua y ArqueologíaFac. de Geografía e HistoriaTRUEsubmitte

Aparicio Alonso, María Teresa

Panera, Joaquin

Pérez-González, Alfredo

Rubio-Jara, Susana

Rubio Jara, Susana

Docta Complutense

  Malacofauna of the late Middle Pleistocene in the Jarama valley: The Valdocarros site (Madrid, Spain)  Aparicio M. T.1, Panera J.2, Rubio-Jara S.2,  Pérez-González A.3 (1)Dept. de Biodiversidad y Biología Evolutiva. Museo Nacional de Ciencias Naturales (C.S.I.C.).C/ José Gutiérrez Abascal, 2. 20006 Madrid (Spain) Email: teresa@mncn.csic.es (2)Dept. de Prehistoria y Arqueología. Universidad Nacional de Educación a Distancia. C/ senda del Rey 9. 28040 Madrid.Email: joaquin.panera@gmail.com, srubiojara@hotmail.com (3)Centro Nacional de Investigación sobre Evolución Humana (CENIEH). Paseo de la Sierra de Atapuerca s/n,09002 Burgos. 09004 Burgos. Email: alfredo.perez@cenieh.es Valdocarros site map Valdocarros site  The taxons found in the site are listed in Table 1, where it is also indicated the habitat origin of the malacofauna, either freshwater or terrestrial (no marine taxons have been found). Table 1 clearly shows that terrestrial species dominated in the site.. Specimens of eleven taxons out of the twenty terrestrial ones are of very small size, that is smaller than five millimetres in size (Euconulus fulvus , Vitrea crystallina, Vitrea contracta, Punctum pygmaeum , Pupilla muscorum , Vallonia costata, Vallonia excentrica, Acantinula aculeata, Truncatellina cylindrical, Truncatellina callicratis, Vertigo angustior). From a total of eleven taxons, the eight freshwater species identified  here occur  in the fine fraction ( Potomida littoralis, Radix balthica and Ancylus fluviatilis are therefore excluded). Our results indicate the importance of using very meticulous methods when extracting material from the archaeological sites. Seven of the species found in Valdocarros also exist in the Aridos site (the more similar site in the region; Robles, 1980) (Cepaea nemoralis,  Punctum pygmaeum, Discus rotundatus, Vallonia costata , Limax sp1, Clausilia sp1,  Anisus spirorbis). However, the Valdocarros stratigraphical level is younger as it is located just above the Aridos one (Sesé et al. 2011). We find a mixture of different ecological elements within this malacofauna assemblage, although dry open ground species predominate, together with other ones typical of marshes and humid places, ubiquitous zones and woodlands. The formation of the site as a sedimentary terrace of the Jarama river might explain the existence of such a biodiversity (taking in account also the freshwater species). A temperate climate might explain the presence of the freshwater taxons, the growth of a developed vegetation cover, riverside vegetation, as well as open areas, that support the malacofauna already described. The great majority of these taxons could live today in the area, should the habitat has not been degraded. However the present malacofauna inhabiting the adjacent areas shows a higher number of xerophile species that the assemblages found in the Valdocarros site, and some humid-related species are missing (Bragado, et al, 2010).  The origin and age of the Iberian Peninsula malacofauna is poorly understood, as these Peninsular molluscs have been scarcely studied. The Valdocarros site is interesting because of its old quaternary age (ca. 300-200 ka) and because the analyzed fauna is similar to the actual one. This confirms the results of Kerney (1959, 1971) and Evans (1972) in the British Islands. The great majority of the species present in this site occurred in Hoxniam Interglacial (Evans, 1972). One exception is Helicella itala that appears later in the Britith Islands, in Eamian Interglacial, although is very scarce in the Valdocarros.This species has been collected in Padul site (Madurga, 1973) belonging to a similar Pleistocene age (with less precision).Cepaea nemoralis represents the oldest record of the present malacofauna assemblage (Lower Plesitocene; Evans 1972). The mollusca remains of the studied site display a good conservation state, with very few damaged shells, with no rolling marks, and few chips. This suggests that molluscan remains were quickly buried in the sediment, with very little transport and no far from the area of initial deposition, in agreement with the constitution of the site as a sedimentary terrace of the Jarama river. Among the freshwater molluscs Potomida littoralis, Valvata piscinalis, Anisus spirorbis and Gyraulus albus, lives in dam waters, thus further supporting the hypothesis of a sedimentary river terrace.      Bibliography   Bar, D.E. & Mayer Y., 2005. Archaeomalacology. Molluscs in former environments of human behaviour. Oxbow Books. Oxford. 184 pp. Bragado, M.D., Araujo, R. & Aparicio, M.T. 2010. Atlas y Libro Rojo de los Moluscos de Castilla-La Mancha. Organismo Autónomo Espacios naturales de Castilla-La Mancha. Guadalajara. 506 pp. Davies, P. 2008. Snails Archaeology and landscape change. Oxbow Books Oxford. 199 pp. Evans, J.G. 1972. Land Snails in Archaeology. With special reference to the British Isles. Seminar Press. London and New York. 436 pp. Kerney, M. P. 1959. An interglacial tufa near Hitchin, Hertfordshire. Proc. Geol. Ass, 70: 322-337. Kerney, M.P. 1971. Interglacial deposists in Barnfield Pit, Swanscombe, and their molluscan fauna. J.Geol.Soc., 127: 69-93. Madurga, M.C. 1973. los Gasterópodos dulceacuicolas y terrestres del Cuaternario español. Bol.R.Soc.Española Hist.Nat. (Geol..), 71: 43-166. Robles F. 1980. Los moluscos del Pleistoceno medio de Aridos-1 (Arganda, Madrid). Ocupaciones Achelenses en el valle del Jarama. Publicaciones de la Excelentísima Diputación Provincial de Madrid. pp 81-91. Sesé, C., Aparicio, M.T. & Pérez-Gonzalez, A. 2004. Moluscos y microvertebrados del Pleistoceno de las terrazas del río Tajo en Toledo y Fuentidueña de Tajo (España Central). Geogaceta, 36: 183-186. Sesé, C., Panera, J.; Rubio-Jara, S., Pérez-González, A. 2011. Micromamíferos del Pleistoceno Medio y Pleistoceno Superior en el valle del Jarama: Yacimientos de Valdocarros y Hat (Madrid). Estudios Geológicos [online], accepted manuscripts  DOI  10.3989/egeol.40290.127 Potomida littoralis (Cuvier , 1798)  Cepaea nemoralis and Helicella sp.1  Gasteropod  eggs  Truncatellina  cylindrica Valdocarros sample Given the unfeasibility of washing all sediments from this archaeological site, statistical criteria were used in the study area to select representative samples, and the GPS coordinates of the sediments obtained after concentrating the were recorded. The molluscs specimens were washed/sieved sediments (using 5 and 2 mm sieves), and they were separated using tweezers and a binocular magnifying glass. The mollusc samples were determined at the lowest possible taxonomical level, i.e., species. Despite the fact that molluscs remain well preserved in some ancient sediments and soils, and are the most common invertebrate remains in archaeological sites, they have received little attention (Bar & Mayer 2005; Davies 2008). It is well documented that land snails are sensitive to climatic changes and have detailed habitat requirements. Thus they are useful for reconstructing past environments. However early work based in picking large shells directly from sediments are now recognised inadequate because of the small size of many of the shells.  In this work we analyzed the malacofauna from Valdocarros II, a huge excavation (836 m2 excavated surface) located in central Spain. The site had provide interesting information about different faunas assemblages and human lithic industry (Sesé et al, 2011). Valdocarros belongs to the Arganda Terrace Complex of the Jarama river valley of Madrid (Spain), and it has been dated as advanced-Middle Pleistocene (MIS 8-7 ca., 300-200 ka). It is worth mentioning that little work has been done on the quaternary continental molluscs in the Iberian Peninsula on such old quaternary faunas (Madurga, 1973; Robles, 1980; Sesé et al., 2004) Material and Methods Introduction Results and Discussion  Table 1: Continental Molluscan from Valdocarros site  (Madrid, Spain)  Terrestrial taxons                                                       Freshwater taxons Valdocarros sample Vertigo angustior 

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Malacofauna of the late Middle Pleistocene in the Jarama valley: The Valdocarros site (Madrid, Spain)

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Malacofauna of the late Middle Pleistocene in the Jarama valley: The Valdocarros site (Madrid, Spain)

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