Introduction
⌅The fossil record of large continental vertebrates in Eastern Andalusia is abundant, mainly related to the sedimentary infilling of intramountain Neogene basins (e.g. Aguirre, 1957Aguirre, E. (1957). Una prueba paleomastológica de la edad cuaternaria de los Conglomerados de La Alhambra (Granada). Estudios Geológicos, 13: 135-140.; Aguirre et al., 1973Aguirre, E., Lhenaff, R. & Zazo, C. (1973). Nuevos fósiles de elefantes en Andalucía. Estudios Geológicos, 29: 295-306.; Martín-Penela, 1988Martín-Penela, A. (1988). Los grandes mamíferos del yacimiento Achelense de la Solana del Zamborino, Fonelas (Granada, España). Antropología y Paleoecología Humana, 5: 29-188.; Arribas & Palmqvist, 1998Arribas, A. & Palmqvist, P. (1998). Taphonomy and palaeoecology of an assemblage of large mammals: Hyanid activity in the Lower Pleistocene site at Venta Micena (Orce, Guadix,-Baza Basin, Granada, Spain). Geobios, 31: 3-47. https://doi.org/10.1016/S0016-6995(98)80056-9 ; Álvarez-Lao et al., 2009Álvarez-Lao, D.J., Kahlke, R.D., García, N. & Mol, D. (2009). The Padul mammoth finds - On the southernmost record of Mammuthus primigenius in Europe and its southern spread during the Late Pleistocene. Palaeogeography, Palaeoclimatology, Palaeoecology, 278: 57-70. https://doi.org/10.1016/j.palaeo.2009.04.011 ; Arribas et al., 2009Arribas, A., Garrido, G., Viseras C, Soria, J.M., Pla, S., Solano, J.G., Garcés, M., Beamud, E. & Carrión, J.S. (2009). A Mammalian Lost World in Southwest Europe during the Late Pliocene. PLoS ONE, 4(9): e7127. https://doi.org/10.1371/journal.pone.0007127 https://doi.org/10.1371/journal.pone.0007127 ; Ros-Montoya, 2010Ros-Montoya, S. (2010). Los Proboscídeos del Plio-Pleistoceno de las Cuencas de Guadix-Baza y Granada. PhD Thesis, University of Granada, 403 pp.; Madurell-Malapeira et al., 2014Madurell-Malapeira, J., Ros-Montoya, S., Espigares, M.P., Alba, D.M., Aurell-Garrido, P. (2014). Villafranchian large mammals from the Iberian Peninsula: paleobiogeography, paleoecology and dispersal events. Journal of Iberian Geology, 40: 167-178. https://doi.org/10.5209/rev_JIGE.2014.v40.n1.44093 ; Martínez-Navarro et al., 2018Martínez-Navarro, B., Ros-Montoya, S., Espigares, M.P., Madurell-Malapeira, J. & Palmqvist, P. (2018). Los mamíferos del Plioceno y Pleistoceno de la Península Ibérica. Revista PH, 94: 206-249. https://doi.org/10.33349/2018.0.4203 ). These basins evolved from marine to lacustrine environments due to the elevation of the Betic Cordillera (e.g. Vera, 1970Vera, J.A. (1970). Estudio estratigráfico de la depresión de Guadix-Baza. Boletín del Instituto Geológico y Minero de España, 81: 429-462.; Braga et al., 1990Braga, J.C., Martín, J.M. & Alcalá, B. (1990). Coral reefs in coarse terrigenous sedimentary environments (upper Tortonian, Granada basin, S. Spain). Sedimentary Geology, 66: 135-150. https://doi.org/10.1016/0037-0738(90)90011-H , 2003Braga, J.C., Martín, J.M. & Quesada, C. (2003). Patterns and averages of late Neogene-Recent uplift of the Betic Cordillera, SE Spain. Geomorphology, 50: 3-26. https://doi.org/10.1016/S0169-555X(02)00205-2 ; Viseras, 1991Viseras, C. (1991). Estratigrafía y sedimentología del relleno aluvial de la cuenca de Guadix (Cordilleras Béticas). PhD Thesis, University of Granada, 327 pp.; Fernández et al., 1993Fernández, J., Bluck, B.J. & Viseras, C. (1993). The effects of fluctuating base-level on the structure of alluvial-fan associated fan delta deposits: an example from the Tertiary of the Betic Cordillera, Spain. Sedimentology, 40: 879-893. https://doi.org/10.1111/j.1365-3091.1993.tb01367.x ; Viseras & Fernández, 1994Viseras, C. & Fernández, J. (1994). Channel migration patterns and related sequences in some alluvial-fan systems. Sedimentary Geology, 88: 201-217. https://doi.org/10.1016/0037-0738(94)90062-0 ; Viseras et al., 2003Viseras, C., Calvache, M.L., Soria, J.M. & Fernández, J. (2003). Differential features of alluvial fans controlled by tectonic or eustatic accomodation space. Examples from the Betic Cordillera, Spain. Geomorphology, 50: 181-202.). The high erosion rate of the reliefs favoured the development of fan deltas and alluvial fans in these basins, as well as the development of endorheic basins (Braga et al., 1990Braga, J.C., Martín, J.M. & Alcalá, B. (1990). Coral reefs in coarse terrigenous sedimentary environments (upper Tortonian, Granada basin, S. Spain). Sedimentary Geology, 66: 135-150. https://doi.org/10.1016/0037-0738(90)90011-H ; Fernández et al., 1993Fernández, J., Bluck, B.J. & Viseras, C. (1993). The effects of fluctuating base-level on the structure of alluvial-fan associated fan delta deposits: an example from the Tertiary of the Betic Cordillera, Spain. Sedimentology, 40: 879-893. https://doi.org/10.1111/j.1365-3091.1993.tb01367.x ; Viseras & Fernández, 1994Viseras, C. & Fernández, J. (1994). Channel migration patterns and related sequences in some alluvial-fan systems. Sedimentary Geology, 88: 201-217. https://doi.org/10.1016/0037-0738(94)90062-0 ; Viseras et al., 2003Viseras, C., Calvache, M.L., Soria, J.M. & Fernández, J. (2003). Differential features of alluvial fans controlled by tectonic or eustatic accomodation space. Examples from the Betic Cordillera, Spain. Geomorphology, 50: 181-202.; Soria et al., 2003Soria, J.M., Fernández, J., García, F. & Viseras, C. (2003). Correlative lowstand deltaic and shelf systems in the Guadix Basin (Late Miocene, Betic Cordillera, Spain): The stratigraphic record of forced and normal regressions. Journal of Sedimentary Research, 73: 912-925. https://doi.org/10.1306/031103730912 ; García-García et al., 2006aGarcía-García, F., Fernández, J., Viseras, U. & Soria, J.M. (2006a). Architecture and sedimentary facies evolution in a delta stack controlled by fault growth (Betic Cordillera, southern Spain, late Tortonian). Sedimentary Geology, 185: 79-92. https://doi.org/10.1016/j.sedgeo.2005.10.010 , bGarcía-García, F., Fernández, J., Viseras, C. & Soria, J.M. (2006b). High frequency cyclicity in a vertical alternation of Gilbert-type deltas and carbonate bioconstructions in the late Tortonian, Tabernas Basin, Southern Spain. Sedimentary Geology, 192: 123-139. https://doi.org/10.1016/j.sedgeo.2006.03.025 ; Stokes, 2008Stokes, M. (2008). Plio-Pleistocene drainage development in an inverted sedimentary basin: Vera basin, Betic Cordillera, SE Spain. Geomorphology, 100: (193-211). https://doi.org/10.1016/j.geomorph.2007.10.026 ; Harvey et al., 2018Harvey, A.M., Stokes, M., Mather, A. & Whitfield, E. (2018). Spatial characteristics of the Pliocene to modern alluvial fan successions in the uplifted sedimentary basins of Almeria, SE Spain: review and regional synthesis. Geological Society Special Publication, 440: DOI: 10.1144/SP440.5 https://doi.org/10.1144/SP440.5 ). Some records of large mammals have been traced to Miocene and Pliocene fan deltas (e.g. Reolid et al., 2016Reolid, M., García-García, F., Reolid, J., de Castro, A., Bueno, J.F., & Martín-Suárez, E. (2016). Palaeoenvironmental interpretation of a sand-dominated coastal system of the Upper Miocene of Eastern Guadalquivir Basin (south Spain): fossil assemblages, ichnology and taphonomy. Journal of Iberian Geology, 42: 275-290. https://doi.org/10.5209/JIGE.52886 ; Sendra et al., 2020Sendra, J., Reolid, M. & Reolid, J. (2020). Palaeoenvironmental interpretation of the Pliocene fan-delta system of the Vera Basin (SE Spain): Fossil assemblages, ichnology and taphonomy. Palaeoworld, 29: 769-788. https://doi.org/10.1016/j.palwor.2019.11.001 ). These intramountain Neogene basins are related with the Internal Zones of the Betic Cordillera, but the record of large land mammals in the Guadalquivir foreland basin is scarcer and exclusively linked to the Western Guadalquivir Basin (Van der Made & Mazo, 2001Van der Made, J. & Mazo, A.V. (2001). Spanish Pleistocene Proboscidean diversity as a function of climate. The World of Elephants-International Congress, Rome, pp. 214-218.; Baena-Escudero et al., 2011).
In this work we report the first record of a proboscidean from the Eastern Guadalquivir Basin related to alluvial fans coming from the outermost mountain front of the Betic Cordillera, and we describe the taphonomic history and conditions that favoured its preservation.
Geological settig
⌅The studied Cuadros outcrop (37º48´19´´N, 3º24´51´´W) is located on the north side of the Sierra Mágina (Betic Cordillera) in Jaén province (Fig. 1). The outcrop is found 1.8 km from Bedmar, along road JV-3222 to Cuadros. From a geological point of view, the outcrop is located by the southern margin of the Guadalquivir Basin, the foreland basin of the Betic Orogen (Fig. 1), whose formation began in the Miocene (García-Castellanos et al., 2002García-Castellanos, D., Fernández, M. & Torné, M. (2002). Modeling the evolution of the Guadalquivir foreland basin (southern Spain). Tectonics, 21: art. no.-1018. https://doi.org/10.1029/2001TC001339 ). A transpressive accretionary complex occupies this southern margin, with heterogeneous tectonic units that move over a thick evaporitic sole of Subbetic affinity (Pérez-Valera et al., 2017Pérez-Valera, F., Sánchez-Gómez, M., Pérez-López, A. & Pérez-Valera, L.A. (2017). An evaporite-bearing accretionary complex in the northern front of the Betic-Rif Orogen. Tectonics, 36: 1006-1036. doi:10.1002/2016TC004414 https://doi.org/10.1002/2016TC004414 ). Miocene infill consists of marls, sandstones and bioclastic sandstones (García-García et al., 2014García-García, F., Corbí, H., García-Ramos, D.A., Soria, J.M., Tent-Manclús, J.E. & Viseras, C. (2014). El sector nororiental de la Cuenca de Antepaís del Guadalquivir (Cordillera Bética, Mioceno Superior): estratigrafía, cronología y evolución sedimentaria. Revista de la Sociedad Geológica de España, 27: 187-204.). In the Eastern Guadalquivir, where the outcrop lies, marine sedimentation reaches the Early Messinian (Martín et al., 2014Martín, J.M., Puga-Bernabeu, A., Aguirre, J. & Braga, J.C. (2014). Miocene Atlantic-Mediterranean seaways in the Betic Cordillera (Suthern Spain). Revista Sociedad Geologica de España, 27: 175-186.).
The alternation of thrust and strike-slip faults together with the abundance of subsoil salt (Pérez-Valera et al., 2017Pérez-Valera, F., Sánchez-Gómez, M., Pérez-López, A. & Pérez-Valera, L.A. (2017). An evaporite-bearing accretionary complex in the northern front of the Betic-Rif Orogen. Tectonics, 36: 1006-1036. doi:10.1002/2016TC004414 https://doi.org/10.1002/2016TC004414 ) forms a smooth but varied landscape in the Guadalquivir Valley, with low hills and endorheic and quasi endorheic mini-basins (Ortega el al., 2006Ortega, F., Parra, G. & Guerrero, F. (2006). Land uses in the hydrographic basins of the Alto Guadalquivir wetlands: The importance of a suitable management. Limnetica, 25: 723-732.). Lakes, many of them saline, were a common feature (López-González et al., 1998López-González, P.J., Guerrero, F. & Castro Pérez, M.C. (1998). Seasonal fluctuations in the plankton community in a hypersaline temporary lake (Honda, Southern Spain), International Journal of Salt Lake Research, 6: 353-371. https://doi.org/10.1007/BF02447916 ). Towards the south, thicker tectonic units of Mesozoic carbonates are structured as a fold-and-thrust belt (García-Rossel & Pezzi, 1975) that results in a mountain range (Sierra Mágina) with peaks above 2000 m high. An intricate mountain front separates the accretionary wedge from Sierra Mágina (García-Tortosa et al., 2008García-Tortosa, F.J., Sanz de Galdeano, C., Sánchez-Gómez, M. & Alfaro, P. (2008). Tectónica reciente en el frente de Cabalgamiento Bético. Las deformaciones de Jimena y Bedmar (Jaén). Geogaceta, 44: 59-62.). Frequent and mighty springs drain into the valley at the foot of the mountain front (Gollonet et al., 2002Gollonet, J., González-Ramón, A. & Rubio-Campos, J.C. (2002). Nuevas aportaciones sobre el funcionamiento hidrogeológico del sistema kárstico de Sierra Mágina. In: Karst and Environment (Carrasco, F., Durán, J.J. & Andreo, B., Eds.), Fundación Cueva de Nerja, Málaga, p. 9.; González-Ramón et al., 2013González-Ramón, A., López-Chicano, M. & Rubio-Campos, J.C. (2012). Piezometric and hydrogeochemical characterization of groundwater circulation in complex karst aquifers. A case study: The Mancha Real-Pegalajar aquifer (Southern Spain). Environmental Earth Science, 67: 923-937. doi:10.1007/s12665-012-1529-y https://doi.org/10.1007/s12665-012-1529-y ), where the tributaries of the Guadalquivir are born.
Tectonic activity remains until nowadays (Sanz de Galdeano et al., 2012Sanz de Galdeano, C., García-Tortosa, F.J. & Peláez, J.A. (2012). Estructura del Prebético de Jaén (Sector de Bedmar). Su relación con el avance del Subbético y con fallas en el basamento. Revista de la Sociedad Geológica de España, 26: 55-68.; Sánchez-Gómez et al., 2014Sánchez-Gómez, M., Peláez, J.A., García-Tortosa, F.J., Pérez-Valera, F. & Sanz de Galdeano, C. (2014). La serie sísmica de Torreperogil (Jaén, Cuenca del Guadalquivir oriental): evidencias de deformación tectónica en el área epicentral. Revista de la Sociedad Geológica de España, 27: 301-318.) through large-scale faults and folds that could have controlled the development of subsiding and uplifting areas, favouring either the preservation or the erosion of Quaternary deposits in the Guadalquivir Valley (Pérez-Valera et al., 2012Pérez-Valera, F., Sánchez-Gómez, M., Peláez, J.A. & Pérez-Valera, L.A. (2012). Fallas de edad Pleistoceno superior en el entorno del terremoto de Huesa, Jaén (4.4 mbLg, 31/01/2012): implicaciones sismotectónicas. Geogaceta, 52: 25-28.).
The tusk remain is located in a dissected conglomeratic body, part of a lateral alluvial fan developed over the Bedmar valley floor at that time. The approximate height of the top and bottom of this alluvial fan would be respectively 40 and 60 m above the current riverbed (Cuadros river). This height correlates with the two levels of terraces, of +30 and +50 m, attributed to the Middle Pleistocene (300-600 ka respectively; Calero et al., 2008Calero, J., Delgado, R., Delgado, G. & Martín-García, J.M. (2008). Transformation of categorical field soil morphological properties into numerical properties for the study of chronosequences. Geoderma, 145: 278-287. https://doi.org/10.1016/j.geoderma.2008.03.022 ), situated in the Guadalquivir main valley, 50 km away from the Bedmar outcrop. Nevertheless, another tributary stream, 16 km away, has fluvial infilling indicating a humid climate; it reaches terrace levels at +45 m above the riverbed and yields a radiocarbon age of 32-35 ka (García-García et al., 2016García-García, F., Calero, J. & Pérez-Valera, F. (2016). Morphological, pedological, and sedimentary evolution of the fringe of the southwestern European druylands during the Late Pleistocene and Holocene : Evidence of climate and land use changes. Catena, 143: 128-139. https://doi.org/10.1016/j.catena.2016.03.023 ). Thus, both ages (Middle to Late Pleistocene) could fit with the age of the alluvial fan deposition.
Materials and methods
⌅Sedimentary analysis of the outcrop was carried out in the field with special attention to the beds surrounding the fossil bone. Small fragments of the bone as well as the carbonate sedimentary coating were retrieved. The specimen was not retired from the outcrop.
Four thin sections were prepared to analyse the fabric of the carbonate coating with a Leica M205C at the University of Jaén (Spain), with close observation of the texture and the presence of fossil organic microstructures. Some fragments of this carbonate coating were analysed under Scanning Electron Microscopy (SEM), through secondary electron images with a Merlin Carl Zeiss SEM, at the CICT (University of Jaén).
The Schreger lines of two small fragments were studied. These lines were first defined in the early 19th century by Bernhard Gottlob Schreger (1800)Schreger, B.N.G., 1800. Beitrag zur Geschichte der Zähne. Beitrage für die Zergliederungkunst, 1: 1-7. as a peculiar feature of the Proboscidean dentine (see more details in Espinoza & Mann, 1993Espinoza, E.O. & Mann, M.J. (1993). The history and significance of the Schreger pattern in proboscidean ivory characterization. Journal of the American Institute for Conservation, 32: 241-248. https://doi.org/10.1179/019713693806124866 ). Schreger lines are observed in transversal sections of the tusk, constituting a pattern of two different sets of curved lines that intersect, one in a clockwise direction and the other counter-clockwise. These lines form angles among them, and the set of lines and angles constitutes the “Schreger pattern” (Espinoza & Mann, 1993Espinoza, E.O. & Mann, M.J. (1993). The history and significance of the Schreger pattern in proboscidean ivory characterization. Journal of the American Institute for Conservation, 32: 241-248. https://doi.org/10.1179/019713693806124866 , 1994Espinoza, E.O. & Mann, M.J. (1994). Mammoth or elephant ivory? Forensics provides the key. Endangered Species Technical Bulletin, 19: 8-9.; Palombo & Villa, 2001Palombo, M.R. & Villa, P. (2001). Schreger lines as support in the Elephantinae identification. Abstracts The World of Elephants - International Congress, Rome. 656-660. https://doi.org/10.1086/342431 ; Ferretti, 2003Ferretti, M.P. (2003). Structure and evolution of mammoth molar enamel. Acta Palaeontologica Polonica, 48: 383-396.; Trapani & Fisher, 2003Trapani, J. & Fisher, D.C. (2003). Discriminating proboscidean taxa using features of the Schreger pattern in tusk dentin. Journal of Archaeological Science, 30: 429-438. https://doi.org/10.1006/jasc.2002.0852 ; Lambert, 2005Lambert, W.D. (2005). The microstructure of proboscidean ivory and its application to the subordinal identification of isolated ivory specimens. Bulletin of the Florida Museum of Natural History, 45: 521-530., Ros-Montoya, 2010Ros-Montoya, S. (2010). Los Proboscídeos del Plio-Pleistoceno de las Cuencas de Guadix-Baza y Granada. PhD Thesis, University of Granada, 403 pp.; Agostini et al., 2012Agostini, S., Palombo, M.R., Rossi. M.A., Di Canzio, E. & Tallini, M. (2012). Mammuthus meridionalis (Nesti, 1825) from Campo di Pile (L’Aquila, Abruzzo, Central Italy). Quaternary International, 276-277: 42-52. https://doi.org/10.1016/j.quaint.2012.05.013 ). The Schreger pattern for elephants is characteristic of each species, since their angles are different. This makes it possible to discriminate taxa with a very high reliability. Thus, analysis of the Schreger lines lends valuable support for the taxonomic identification of Proboscidean when the bone remains found in the site are not conclusive (e.g. Mausouss et al., 2014Mausouss, A., Valessi, P. & Simon, P. (2014). Identification de l’ivoire de Proboscidiens des Grottes des Balzi Rossi (Ligurie, Italie) à Partir de la Méthode des Lignes De Schreger. Bulletin Musée Anthropologie préhistoire Monaco, 54, 83-90.).
Primarily two large fragments were selected and photographed with a high-resolution camera, then the angles between lines were measured using Dino-Lite Pro AM4000 and Photoshop CS6 software, to determine their values and relate them to the taxonomic genus.
Results
⌅Sediment
⌅The tusk remain was recorded in detritic sediments made up mainly of conglomerates and coarse sands (Fig. 2). The conglomerates range from pebbles to boulders, locally over 90 cm in size. Conglomerates are commonly constituted by Jurassic and Cretaceous limestones and dolostones. These lithologies are the most common ones in the surrounding reliefs of Sierra Mágina and Sierra de Bedmar. Some sand layers are observed, laterally and stratigraphically eroded by conglomerates. Sands are massive and show slight cross-stratification. The tusk remain was found at the base of a sand layer.
The conglomerate deposits present clast-supported fabric with an erosive base, indicating palaeochannels. Clast imbrication is observed when the clasts are from 3 to 15 cm long. However, grain-size sequences were not identified. An additional fabric in the case of conglomerates is matrix supported —not describing bedding, but irregular lens-shaped bodies. These deposits are interpreted as debris flows.
The tusk remains
⌅The studied remain is a straight fragment of proboscidean tusk measuring 74 cm in length and having a diameter ranging from 15.2 to 11.4 cm (Fig. 2 B, C). Its preservation in the outcrop is very poor; some parts of the dentine are deteriorated or stained with patches of chalky to chipped appearance. The fossil tusk is coated by a carbonate crust less than 2 cm thick (Fig. 2 D). The remain deepens 24º north, at the base of a sandy bed some 40 cm thick.
During their ontogenetic development, elephant tusks progressively form series of dentin cones that intertwine with tubular bundles carrying blood (Fig. 3 A). This ivory is easily distinguishable from other groups, for example hippos, since making a transversal cut reveals a pattern of curved lines crossing each other, the Schreger lines. The Schreger pattern of lines and angles is not influenced by palaeoenvironmental factors or linked to the sex of the individual.
Analyses of the Schreger pattern was carried out on two tusk fragments selected from the inner part of the specimen retrieved from the Cuadros outcrop (Fig. 3 B and C). The first fragment shows a pattern of lines in the lower left corner, but the fracture is not perpendicular to the axis of the tusk, meaning it is not possible to measure the angle formed by the Schreger lines (Fig. 3 D). The other sample shows two sets of lines (Fig. 3 C). Several angles were measured on this surface (Fig. 3 E), with an average value of 106.5º. The graph in Fig. 3 F (modified from Palombo & Villa, 2001Palombo, M.R. & Villa, P. (2001). Schreger lines as support in the Elephantinae identification. Abstracts The World of Elephants - International Congress, Rome. 656-660. https://doi.org/10.1086/342431 ), based on more than 200 specimens, shows that the studied specimen corresponds to the genus Palaeoloxodon.
Carbonate coating
⌅A coating of carbonate, with poorly laminated fabric from a macroscopic point of view, surrounds most of the fossil bone (Fig. 2 C, D). This coat consists of laminated brownish, creamy limestone with a porous appearance. Porosity is characterized by elongated lamina-parallel pores, but pores arranged 90º with respect to the laminae are also recorded. The total thickness is commonly less than 2 cm. The laminae are more or less continuous, yet of variable thickness. Under petrographic microscopy, lamination is seen to be organized in two types of bands (Fig. 4): porous and compact bands.
The porous laminated bands range from 6 to 10 mm in thickness; they comprise thick laminae (1 to 3.5 mm, average 2 mm) with phytal shrub appearance and high porosity (Fig. 4 A-C). These bands constitute laminated bindstones of vegetal remains. In turn, the compact laminated bands, less than 1.3 mm thick, have alternating clear and dark thin laminae (90 to 480 µm thick, average 200 µm) of low porosity. The surface of some porous laminated bands evidences irregularities related to erosion.
The SEM analyses allowed us to identify clusters of multibranched stalks, locally with fan appearance, in the porous bands (Fig. 5). The stalks have a diameter ranging from 8 to 20 µm, and in detail, are composed by calcite crystals from 1 to 10 µm. The central part of the stalks shows a hollow (2 - 4 µm in diameter) delimited by the calcite crystals.
Discussion
⌅The fossil tusk fragment is recorded in detritic sediments evidencing high energy conditions, given the presence of boulders and debris flow. The environment was probably the proximal part of an alluvial fan that formed surrounding the palaeoreliefs of the Sierra Mágina. The potential presence of scavengers as well as surficial water streams favoured the fragmentation, dispersion and transport of remains. Such scenarios are typical for large corpses of vertebrates from terrestrial environments (e.g. Behrensmeyer, 1988Behrensmeyer, A.K. (1988). Vertebrate preservation in fluvial channels. Palaeogeography, Palaeoclimatology, Palaeoecology, 63: 183-199. https://doi.org/10.1016/0031-0182(88)90096-X ). The disarticulated tusk or fragment of tusk would have eventually been transported by the water streams feeding the alluvial fan. In this environment, the surface of the tusk was colonized mainly by mosses and thin microbial mats. Water from the karstic carbonate system of Sierra Mágina favoured the precipitation of carbonate upon the mosses. Therefore, the carbonate coating constitutes a phytothermal bindstone, the porous bands of laminated bindstones of bryophytes alternating with compact laminated bands interpreted as microbial mats.
The carbonate coating played an essential role in the preservation of this vertebrate remain. From a taphonomic standpoint, the growth of mosses around the fragment of the elephant tusk, as well as early carbonate cementation, protected the remains from erosion and weathering. The presence of erosive surfaces within the laminae of the carbonate coating is congruent with a local high-energy environment. However, the growth of mosses and the cementation could have been very fast processes, at a seasonal scale. Subsequent burial by new input of detrital deposits in the alluvial fan determined the preservation.
In view of the average value (106.5º) of the inner Schreger angles of the Cuadros specimen (Fig. 3) and the model by Palombo & Villa (2001; Fig. 3 F)Palombo, M.R. & Villa, P. (2001). Schreger lines as support in the Elephantinae identification. Abstracts The World of Elephants - International Congress, Rome. 656-660. https://doi.org/10.1086/342431 , the specimen would coincide with the genus Palaeoloxodon.
The genus Mammuthus presents inner Schreger angles less than 90º and therefore narrower than in the Palaeoloxodon (Fisher et al., 1998Fisher, D.C., Trapani, J., Shoshani, J. & Woodford, M.S. (1998). Schreger angles in Mammoth and Mastodon tusk dentin. Current Research in the Pleistocene, 15: 105-106.; Agostini et al., 2012Agostini, S., Palombo, M.R., Rossi. M.A., Di Canzio, E. & Tallini, M. (2012). Mammuthus meridionalis (Nesti, 1825) from Campo di Pile (L’Aquila, Abruzzo, Central Italy). Quaternary International, 276-277: 42-52. https://doi.org/10.1016/j.quaint.2012.05.013 ). The values of the outer Schreger angles of Mammuthus, in the dentine-cementum junction, are higher than the inner Schreger angles (Palombo & Villa, 2001Palombo, M.R. & Villa, P. (2001). Schreger lines as support in the Elephantinae identification. Abstracts The World of Elephants - International Congress, Rome. 656-660. https://doi.org/10.1086/342431 , 2007Palombo, M.R. & Villa, P. (2007). L’utilità dell’analisi delle linee di Schreger nello studio dei Proboscidati. In: Fiore, I., Malerba, G. & Chilardi, S. (Eds.), Atti del 3 Congresso Internazionale di Archeozoologia. Collana del Bollettino di Paleontologia Italiana, Roma, Studi di Paleontologia, 2: 35-44.; Trapani & Fisher, 2003Trapani, J. & Fisher, D.C. (2003). Discriminating proboscidean taxa using features of the Schreger pattern in tusk dentin. Journal of Archaeological Science, 30: 429-438. https://doi.org/10.1006/jasc.2002.0852 ; Agostini et al., 2012Agostini, S., Palombo, M.R., Rossi. M.A., Di Canzio, E. & Tallini, M. (2012). Mammuthus meridionalis (Nesti, 1825) from Campo di Pile (L’Aquila, Abruzzo, Central Italy). Quaternary International, 276-277: 42-52. https://doi.org/10.1016/j.quaint.2012.05.013 ). Pawłowska et al. (2014)Pawłowska, K., Greenfield, H. Czubla, P. (2014). ‘Steppe’ mammoth (Mammuthus trogontherii) remains in their geological and cultural context from Bełchatów (Poland): A consideration of human exploitation in the Middle Pleistocene. Quaternary International, 326: 448-468. https://doi.org/10.1016/j.quaint.2013.08.047 found Schreger angles reaching 120º in the dentine-cementum junction for Mammuthus. But the Schreger angles measured in the studied specimen are not located at the dentine-cementum junction; they are inner angles, and therefore taxonomic assignation to the genus Mammuthus is discarded.
Analysis of dentinal tubule density for taxonomic determination was discarded due to the fact that the Schreger angles in this case sufficed to identify the genus Palaeoloxodon. According to Agiadi & Theodoru (2005)Agiadi, K. & Theodorou, G. (2005). Tusk Paleohistology as a tool in the discrimination of fossil tusks from Greece. In: Proceedings of the International Symposium “Insular Vertebrate Evolution: the Palaeontological Approach” (Alcover, J.A. & Bover, P., Eds.). Monografies de la Societat d’Història Natural de les Balears, 12: 1-8., dentinal tubule density would not present a discriminating power between Mammuthus meridionalis and Palaeoloxodon antiquus, for example. Moreover, previous authors report that the dentinal tubule density may change depending on the distance from the pulp cavity —toward the outer surface of the tusk, the dentinal tubules branch, anastomose and fuse (Agiadi, 2001Agiadi, K. (2001). Comparative observations on fossil tusks from three Quaternary Greek localities using scanning electron microscopy. The World of Elephants - International Congress Rome 2001, 523-528.). Thus, measuring the density of the tubules, at random distances from the pulp would not provide reliable results, just as comparing the Schreger angles of outer and inner positions in the tusk would be insufficient. The use of inner Schreger angles is therefore held to suffice for identifying the studied sample as Palaeoloxodon.
The average value (106.5º) of the inner Schreger angles obtained for the Cuadros specimen (Fig. 3) is coincident with only two different species according to the model proposed by Palombo & Villa (2001; Fig. 3 F)Palombo, M.R. & Villa, P. (2001). Schreger lines as support in the Elephantinae identification. Abstracts The World of Elephants - International Congress, Rome. 656-660. https://doi.org/10.1086/342431 : Palaeoloxodon antiquus and Palaeoloxodon falconeri. However, Palaeoloxodon falconeri can be discarded as it is a typical island dwarf proboscidean from Sicily (Romano et al., 2019Romano, M., Manucci, F. & Palombo, P. (2019). The smallest of the largest: new volumetric body mass estimate and in-vivo restoration of the dwarf elephant Palaeoloxodon ex. gr. P. falconeri from Spinagallo Cave (Sicily). Historical Biology DOI: 10.1080/08912963.2019.1617289 https://doi.org/10.1080/08912963.2019.1617289 ). The tusk fragment found in the Cuadros outcrop can parsimoniously be said to correspond to Palaeoloxodon cf. antiquus Falconer et Cautley, 1847.
Palaeoloxodon was a genus of the Order Proboscidea (Family Elephantidae) that originated in Africa in the Early Pleistocene and dispersed throughout Central and Southern Europe to Asia during the latest Early Pleistocene, where it rapidly differentiated into various species (e.g. Larramendi et al., 2020Larramendi, A., Zhang, H., Palombo, M.R. & Ferretti, M.P. (2020). The evolution of Palaeoloxodon skull structure: Disentangling phylogenetic, sexually dimorphic, ontogenetic, and allometric morphological signals. Quaternary Science Reviews, 229: art. 106090. https://doi.org/10.1016/j.quascirev.2019.106090 ). Palaeoloxodon antiquus lived in Europe during the Middle and Late Pleistocene, with a wide distribution and diversification of dwarfed insular descendants (see Larramendi et al., 2020Larramendi, A., Zhang, H., Palombo, M.R. & Ferretti, M.P. (2020). The evolution of Palaeoloxodon skull structure: Disentangling phylogenetic, sexually dimorphic, ontogenetic, and allometric morphological signals. Quaternary Science Reviews, 229: art. 106090. https://doi.org/10.1016/j.quascirev.2019.106090 ). The earliest occurrence of this straight-tusked elephant in Europe is documented around 600 - 850 Ka (Madurell-Malapeira et al., 2010Madurell-Malapeira, J., Minwer-Barakat, R., Alba, D.M., Garcés, M., Gómez, M., Aurell-Garrido, J., Ros-Montoya, S., Moya-Sola, S. & Berastegui, X. (2010). The Vallparadis section (Terrassa, Iberian Peninsula) and the latest Villafranchian faunas of Europe. Quaternary Science Reviews, 29: 3972-3982. https://doi.org/10.1016/j.quascirev.2010.09.020 ; Lister, 2015Lister, A.M. (2015). Dating the arrival of straight-tusked elephant (Palaeoloxodon spp.) in Eurasia. Bulletin Musee Anthropologie préhistoire Monaco, suppl. 6: 13-18.). Its last appearances are post-Eemian, at ∼35 ka (Sousa & Figueiredo, 2001Sousa, M.F. & Figueiredo, S.M. (2001). The Pleistocene elephants of Portugal. Abstracts The World of Elephants-International Congress, Rome, pp. 611-616.; Mol et al., 2007Mol, D., de Vos, J. & van der Plicht, J. (2007). The presence and extinction of Elephas antiquus Falconer and Cautley, 1847, in Europe. Quaternary International, 169-170: 149-153. https://doi.org/10.1016/j.quaint.2006.06.002 ; Palombo et al., 2010Palombo, M.R., Albayrak, E. & Marano, F. (2010). The straight-tusked elephants from Neumark-Nord. A glance into a lost world. In: Elefantenreich. Eine Fossilwelt in Europa. Landesamt für Denkmalpflege und Archäologie Sachsen-Anhalt (Meller, H., Ed.), Halle, 219-247.; Athanassiou, 2011Athanassiou, A. (2011). The late Pleistocene fauna of Peneiós valley (Lárissa, Thessaly, Greece): new collected material. 9th Annual Meeting of the European Association of Vertebrate Palaeontologists (Heraklion, Crete), Greece, 14.; Palombo, 2014Palombo, M.R. (2014). Deconstructing mammal dispersals and faunal dynamics in SW Europe during the Quaternary. Quaternary Science Reviews, 96: 50-71 https://doi.org/10.1016/j.quascirev.2014.05.013 ) but dwarfed species of the genus Palaeoloxodon inhabiting Mediterranean islands persisted (∼20 ka in Sicily for Palaeoloxodon ex. gr. mnaidriensis; Palombo et al., 2020Palombo, M.R., Antonioli, F., Di Patti, C., Lo Presti, V. & Scarborough, M.E. (2020). Was the dwarfed Palaeoloxodon from Favignana Island the last endemic Pleistocene elephant from the western ∼35 ka 1080/08912963.2020.1772251). P. antiquus showed a broad ecological adaptation, and has been reported from moderate, humid and warm climates (Garutt & Vangengeim, 1982Garutt, V.E. & Vangengeim, E.A. (1982). Order Proboscidea. In: Stratigraphy of the USSR, Quaternary System (Shantser, E.V., Ed.), pp. 311-317. Nedra, Moscow, Russia.; Stuart, 1991Stuart, A.J. (1991). Mammalian extinctions in the late Pleistocene of Northern Eurasia and North America. Biological Reviews, 66: 453-562.; Konidaris et al., 2018Konidaris, G.E., Athanassiou, A., Tourloukis, V., Thompson, N., Giusti, D., Panagopoulou, E. & Harvati, K. (2018). The skeleton of a straight-tusked elephant (Palaeoloxodon antiquus) and other large mammals from the Middle Pleistocene butchering locality Marathousa 1 (Megalopolis Basin, Greece): preliminary results. Quaternary International, 497: 65-84. https://doi.org/10.1016/j.quaint.2017.12.001 ); it lived in forested areas where it fed on leaves, branches and soft grass (Garutt, 1972Garutt, V.E. (1972). On a finding of the Palaeoloxodon elephant in Eastern Urals. In: Questions of Stratigraphy and Correlation of the Pliocene and Pleistocene Deposits of Northern and Southern Parts of Eastern Urals (Yakhimovich, V.L., Ed.), pp. 19-26. AN SSSR, Geology Institute, Ufa, Bashkirija, Russia, 1986Garutt, V.E. (1986). Origin of elephants, Elephantidae and their phylogeny. In: Mammals of the Quaternary Fauna of the USSR. Proceedings of the Zoological Institute, 149, 15-32.).
According to Maslim & Ridwell (2005)Maslin, M.A. & Ridgwell, P.L. (2005). Mid-Pleistocene revolution and the “eccentricity myth”. Geological Society London, Special Publications, 247: 19-34. https://doi.org/10.1144/GSL.SP.2005.247.01.02 and Clark et al. (2006)Clark, P., Archer, D., Pollard, D., Blum, J.D., Rial, J.A., Brovkin, V., Mix, A.C., Pisias, N.G. & Roy, M. (2006). The middle Pleistocene transition: characteristics, mechanisms, and implications for long-term changes in atmospheric pCO2. Quaternary Science Reviews, 25: 3150-3184. https://doi.org/10.1016/j.quascirev.2006.07.008 , major climatic changes at a global scale occurred in the latest Early Pleistocene had an important impact on the composition of mammalian assemblages. In the neighbouring Guadix-Baza Basin, numerous sites (Baza-1, Fonelas P-1, Venta Micena, Barranco León, Fuente Nueva-3, Huescar-1) show diverse fauna of the Pliocene to Early Pleistocene, composed by Hyanidae, Felidae, Canidae, Ursidae, Mustelidae, Cervidae, Bovidae, Elephantidae, Equidae, Giraffidae, Rhinocerotidae, Hippopotamidae and Suidae, as well as numerous micromammals (Arribas & Palmqvist, 1998Arribas, A. & Palmqvist, P. (1998). Taphonomy and palaeoecology of an assemblage of large mammals: Hyanid activity in the Lower Pleistocene site at Venta Micena (Orce, Guadix,-Baza Basin, Granada, Spain). Geobios, 31: 3-47. https://doi.org/10.1016/S0016-6995(98)80056-9 ; Arribas et al., 2009Arribas, A., Garrido, G., Viseras C, Soria, J.M., Pla, S., Solano, J.G., Garcés, M., Beamud, E. & Carrión, J.S. (2009). A Mammalian Lost World in Southwest Europe during the Late Pliocene. PLoS ONE, 4(9): e7127. https://doi.org/10.1371/journal.pone.0007127 https://doi.org/10.1371/journal.pone.0007127 ; Martínez-Navarro et al., 2010Martínez-Navarro, B., Palmqvist, P., Madurell, J., Ros-Montoya, S., Espigares, M.P., Torregrosa, V. & Pérez-Claros, J.A., 2010. La fauna de grandes mamíferos de Fuente Nueva 3 y Barranco León 5. Estado de la cuestión. In: Ocupaciones Humanas en el Pleistoceno inferior y medio de la cuenca de Guadix-Baza, Memoria Científica (Toro, I., Martínez-Navarro, B. & Agustí, J., Eds), Junta de Andalucía. Consejería de Cultura. E.P.G. Arqueología Monográfico, 197-236.; Rook & Martínez-Navarro, 2010Rook, L. & Martínez-Navarro, B. (2010). Villafranchian: The long story of a Plio-Pleistocene European large mammal biochronologic unit. Quaternary International, 219:134-144. https://doi.org/10.1016/j.quaint.2010.01.007 ; Medin et al., 2017Medin, T., Martínez-Navarro, B., Rivals F., Madurell-Malapeira, J., Ros-Montoya, S., Espigares, M.P., Figueirido, B., Rook, L. & Palmqvist, P. (2017). Late Villafranquian Ursus etruscus and other large carnivorans from the Orce sites (Guadix-Baza Basin, Andalusia, southern Spain): Taxonomy, biochronology, paleobiology, and ecogeographical context. Quaternary International, 431: 20-41. https://doi.org/10.1016/j.quaint.2015.10.053 ; Rodríguez-Gómez et al., 2017Rodríguez-Gómez, G., Palmqvist, P., Ros-Montoya, S., Espigares, M.P. & Martínez-Navarro, B. (2017). Resource availabitilty and competition intensity in the carnivore guild of the Early Pleistocene site of Venta Micena (Orce, Baza Basin, SE Spain). Quaternary Science Reviews, 164: 154-167. https://doi.org/10.1016/j.quascirev.2017.04.006 ; Ros-Montoya et al., 2017Ros-Montoya, S., Martínez-Navarro, B., Espigares, M.P., Guerra-Merchán, A., García-Aguilar, J.M., Piñero, P., Rodríguez-Rueda, A., Agustí, J., Oms, O. & Palmqvist, P. (2017). A new Ruscinian site in Europe: Baza-1 (Baza basin, Andalusia, Spain). Comptes Rendus Palevol, 16: 746-761. https://doi.org/10.1016/j.crpv.2017.05.005 , 2018Ros-Montoya, S., Palombo, M.R., Espigares, M.P., Palmqvist, P. & Martínez-Navarro, B. (2018). The mammoth from the archaeo-paleontological site of Huéscar-1: A tile in the puzzling question of the replacement of Mammuthus meridionalis by Mammuthus trogontherii in the Early Pleistocene of Europe. Quaternary Science Reviews, 197: 336-351. https://doi.org/10.1016/j.quascirev.2018.08.017 ; Espigares et al., 2019Espigares, M.P., Palmqvist, P., Guerra-Merchán, A., Ros-Montoya, S., García-Aguilar, J.M., Rodríguez-Gómez, G., Serrano, F.J. & Martínez-Navarro, B. (2019). The earliest cut marks of Europe: a discussion on hominin subsistence patterns in the Orce sites (Baza basin, SE Spain). Scientific Reports, 9: art.15408. https://doi.org/10.1038/s41598-019-51957-5 ). The faunal turnover occurring around the Early/Middle Pleistocene transition in Iberia involved the extinction of most of the Early Pleistocene large carnivoran taxa such as the giant hyena Pachycrocuta brevirostris, the sabre-tooth felid Megantereon whitei, the jaguar Panthera gombaszoegensis and the canid Lycaon lycaonoides. Herbivores were also affected, including two horse species, Equus altidens and Equus sussenbornensis (Martínez-Navarro et al., 2009Martínez-Navarro, B., Madurell-Malapeira, J., Ros-Montoya, S., Espigares, M.P. (2009). The Early-Middle Pleistocene faunal turnover and arrival of the Acheulian culture into Europe. The Quaternary of southern Spain: a bridge between Africa and the Alpine domain. In: Orce and Lucea (Spain) 2009 SEQS Annual Congress, pp. 30-31., 2018Martínez-Navarro, B., Ros-Montoya, S., Espigares, M.P., Madurell-Malapeira, J. & Palmqvist, P. (2018). Los mamíferos del Plioceno y Pleistoceno de la Península Ibérica. Revista PH, 94: 206-249. https://doi.org/10.33349/2018.0.4203 ). Species of African origin arrived at Europe by this time (Martínez-Navarro & Rabinovich, 2011Martínez-Navarro, B. & Rabinovich, R. (2011). The fossil Bovidae (Artiodactyla, Mammalia) from Gesher Benot Ya’aqov, Israel: Out of Africa during the Early-Middle Pleistocene transition. Journal of Human Evolution, 60: 375-386. https://doi.org/10.1016/j.jhevol.2010.03.012 ): the spotted hyena Crocuta crocuta, the lion Panthera leo, the leopard Panthera pardus, the auroch Bos primigenius and the straight-tusked elephant (recorded in the Cuadros outcrop) Palaeoloxodon antiquus. At the same time, taxa of Asian origin, such as the steppe mammoth Mammuthus trogontherii, the deer Cervus elaphus, an Indian bovid Hemibos galerianus, and the horse Equus ferus, among others, reached Iberia (Martínez-Navarro et al., 2009Martínez-Navarro, B., Madurell-Malapeira, J., Ros-Montoya, S., Espigares, M.P. (2009). The Early-Middle Pleistocene faunal turnover and arrival of the Acheulian culture into Europe. The Quaternary of southern Spain: a bridge between Africa and the Alpine domain. In: Orce and Lucea (Spain) 2009 SEQS Annual Congress, pp. 30-31.; Madurell-Malapeira et al., 2010Madurell-Malapeira, J., Minwer-Barakat, R., Alba, D.M., Garcés, M., Gómez, M., Aurell-Garrido, J., Ros-Montoya, S., Moya-Sola, S. & Berastegui, X. (2010). The Vallparadis section (Terrassa, Iberian Peninsula) and the latest Villafranchian faunas of Europe. Quaternary Science Reviews, 29: 3972-3982. https://doi.org/10.1016/j.quascirev.2010.09.020 ).
In comparison with the neighbouring Guadix-Baza Basin, the record of large Middle Pleistocene mammals recorded in the Solana del Zamborino outcrop (Fonelas) comprises Felidae (Felis, Lynx and Panthera), Canidae (Canis and Vulpes), Cervidae (Capreolus, Cervus, and Dama), Bovidae (Bison and Bos), Elephantidae (Mammuthus and Palaeoloxodon), Equidae (Equus), Rhinocerotidae (Stephanorhinus), Hippopotamidae (Hippopotamus), Suidae (Sus) and Cercopithecidae (Macaca) (Botella-López et al., 1976Botella López, M.C., Dabrio González, M.T. & De Porta, J. (1976). El yacimiento achelense de la “Solana del Zamborino”: Fonelas: Granada: primera campaña de excavaciones. Universidad de Granada. Departamento de Prehistoria, 1976: 1-46.; de Porta, 1976Porta, J. de (1976). Estudio preliminar sobre la fauna de la ‘Solana del Zamborino’. Cuadernos de Prehistoria de la Universidad de Granada, I: 17-23.; Alberdi & Ruiz-Bustos, 1985Alberdi, M.T. & Ruiz-Bustos, A. (1985). Descripción y significado bioestratigráfico y climático de Equus e Hippopotamus, en el yacimiento de Venta Micena (Granada). Estudios Geológicos, 41: 251-261. https://doi.org/10.3989/egeol.85413-4708 ; Martín-Penela, 1983Martín-Penela, A.M. (1983). Presencia del género Macaca en el yacimiento Pleistoceno de la Solana del Zamborino (Fonelas, Granada, España). Boletin de la Real Sociedad Española de Historia Natural, Sección geológica, 81: 187-195., 1988Martín-Penela, A. (1988). Los grandes mamíferos del yacimiento Achelense de la Solana del Zamborino, Fonelas (Granada, España). Antropología y Paleoecología Humana, 5: 29-188.).
The Middle Pleistocene examples of Palaeoloxodon antiquus in South Spain have been reported from fluvial terraces along the Western Guadalquivir Basin by the localities of La Rinconada, Hornachuelos, and Almodóvar del Río in Sevilla and Córdoba provinces (Van der Made & Mazo, 2001Van der Made, J. & Mazo, A.V. (2001). Spanish Pleistocene Proboscidean diversity as a function of climate. The World of Elephants-International Congress, Rome, pp. 214-218.; Baena-Escudero et al., 2014Baena-Escudero, R., Fernández-Caro, J.J., Guerrero-Amador, I. & Posada-Simeon, J.C. (2014). The complex terrace “Las Jarillas” of the Guadalquivir river (La Rinconada, Sevilla, SW of Spain): chronostratigraphy, lithic industry and associated macromammal fauna. Cuaternario y Geomorfología, 28: 107-125.; Table 1). Moreover, Cortes-Sánchez et al. (2017)Cortés-Sánchez, M., Morales-Muñiz, A., Jiménez-Espejo, F., Évora, M., Simón-Vallejo, M.D., García-Alix, A., Martínez Aguirre, A., Riquelme-Cantal, J.A., Odriozola, C.P., Parrilla Giráldez, R. & Álvarez-Lao, D.J. (2017). Multi-purpose fossils? The reappraisal of an Elephas antiquus molar from El Pirulejo (Magdalenian; Córdoba, Spain). Archaeology, Antropology Science, 9: 1287-1303. https://doi.org/10.1007/s12520-016-0324-1 reported this specie from the Cave of El Pirulejo (Córdoba province). In the Granada Basin, P. antiquus has been identified from the Middle Pleistocene of a Loja outcrop (Ros-Montoya, 2010Ros-Montoya, S. (2010). Los Proboscídeos del Plio-Pleistoceno de las Cuencas de Guadix-Baza y Granada. PhD Thesis, University of Granada, 403 pp.; Table 1). The eastern record of P. antiquus in South Spain pertains to the Guadix-Baza Basin (Granada province) by the Solana de Zamborino outcrop (Table 1; Martín-Penela, 1988Martín-Penela, A. (1988). Los grandes mamíferos del yacimiento Achelense de la Solana del Zamborino, Fonelas (Granada, España). Antropología y Paleoecología Humana, 5: 29-188.). The P. cf. antiquus recorded from the Cuadros outcrop is 47 km North of Solana de Zamborino and would be easily connected with the Guadix-Baza Basin through the strait between Sierra Mágina and Sierra de Cazorla relief, which constituted the gateway to the Guadalquivir Basin. Therefore, the record of Palaeoloxodon cf. antiquus from the Cuadros outcrop connects the populations of P. antiquus from the Western Guadalquivir Basin with those of the Guadix-Baza Basin. Seasonal migrations between low lands of the Western Guadalquivir Basin (outcrops at 10 - 200 m above sea level), and high lands of the Granada Basin (outcrops at 500 - 600 m) or the Guadix-Baza Basin (outcrops at 900 - 1200 m) are not discarded. The studied outcrop, 550 m high, lies potentially along the way from the Guadalquivir Basin to the Guadix-Baza Basin. In this sense, African elephants (Loxodonta africana) present seasonal movements related to vegetation dynamics, in turn ruled by dry and wet conditions (e.g. Wittemyer et al., 2007Wittemyer, G., Getz, W.M., Vollrath, F. & Douglas-Hamilton, I. (2007). Social dominance, seasonal movements, and spatial segregation in African elephants: a contribution to conservation behavior. Behavioral Ecology and Sociobiology, 61: 1919-1931. https://doi.org/10.1007/s00265-007-0432-0 ; Wall et al., 2013Wall, J., Wittemyer, G., Klinkenberg, B., LeMay, V. & Douglas-Hamilton, I. (2013). Characterizing properties and drivers of long distance movements by elephants (Loxodonta africana) in the Gourma, Mali. Biological Conservation, 157: 60-68. https://doi.org/10.1016/j.biocon.2012.07.019 ; Bohrer et al., 2014Bohrer, G., Beck, P.S., Ngene, S.M., Skidmore, A.K. & Douglas-Hamilton, I. (2014). Elephant movement closely tracks precipitation-driven vegetation dynamics in a Kenyan forest-savanna landscape. Movement Ecology, 2, art. 2. https://doi.org/10.1186/2051-3933-2-2 ).
| Outcrop | Turolian | Pliocene | Lower Pleistocene | Middle Pleistocene | Upper Pleistocene | Authors |
|---|---|---|---|---|---|---|
| Alfacar (Granada) | M. borsoni, A. arvernensis | Aguirre (1958Aguirre, E. (1958). Novedades paleomastológicas de la Depresión de Granada y estratigrafía de su borde NE. Estudios Geológicos, 14: 107-120., 1974)Aguirre, E. (1974). Depresión de Granada. In: Coloquio Internacional del Neógeno superior y Cuaternario inferior (Aguirre, E. & Morales, J., Eds.), Libro Guía, pp. 175-212. | ||||
| Barranco Quebradas Huescar 3 (Granada) | A. arvernensis | Alberdi & Ruiz-Bustos (1989)Alberdi, M.T. & Ruiz-Bustos, A. (1989). Taxonomía y bioestratigrafía de Equidae (Mammalia, Perissodactyla) en la Cuenca de Guadix-Baza (Granada). Museo Nacional de Ciencias Naturales, 11: 239-271. | ||||
| San Clemente-1 (Granada) | A. arvernensis | Martínez-Navarro et al. (2006)Martínez-Navarro, B., Toro, I., Ros-Montoya, S., Espigares, M.P. & Fajardo, B. (2006). Resultados de la prospección superficial del área de Huéscar (Secor Nororiental de la Cuenca de Guadix-Baza), Campaña 2003. Anuario Arqueológico de Andalucía/2003, Consejería de Cultura de la Junta de Andalucía, Sevilla, pp. 54-59. | ||||
| Baza 1 (Granada) | M. borsoni and A. arvernensis | Ros-Montoya et al. (2017)Ros-Montoya, S., Martínez-Navarro, B., Espigares, M.P., Guerra-Merchán, A., García-Aguilar, J.M., Piñero, P., Rodríguez-Rueda, A., Agustí, J., Oms, O. & Palmqvist, P. (2017). A new Ruscinian site in Europe: Baza-1 (Baza basin, Andalusia, Spain). Comptes Rendus Palevol, 16: 746-761. https://doi.org/10.1016/j.crpv.2017.05.005 | ||||
| Huélago (Granada) | M. meridionalis | Alberdi et al. (2001)Alberdi, M.T., Alonso, M.A., Azanza, B., Hoyos, M. & Morales, J. (2001). Vertebrate taphonomy in the circum-lake environments: three cases in the Guadix-Baza Basin (Granada, Spain). Palaeogeography, Palaeoclimatology, Palaeoecology, 165: 1-26. https://doi.org/10.1016/S0031-0182(00)00151-6 | ||||
| Fonelas P-1 (Granada) | M. meridionalis | Arribas et al. (2001)Arribas, A., Riquelme, J.A., Palmqvist, P., Garrido, G., Hernández, R., Laplana, C., Soria, J., Viseras, C., Durán, J.J., Gurmiel, P., Robles, F., López-Martínez, J. & Carrión, J. (2001). Un yacimiento de grandes mamíferos villafranquienses de la Cuenca Guadix-Baza (Granada): Fonelas P-1, primer registro de una fauna próxima al límite Plio-Pleistoceno en la Península Ibérica. Boletín Geológico y Minero, 112: 3-34. | ||||
| Zújar (Granada) | M. meridionalis | Agustí & Oms (1998)Agustí, J. & Oms, O. (1998). The mammal succession in the Negratín Clay (Jabalcón area). Excursion to the Guadix-Baza Basin Euromam. Junta de Andalucía, pp. 26. | ||||
| Láchar (Granada) | M. meridionalis | Aguirre (1974)Aguirre, E. (1974). Depresión de Granada. In: Coloquio Internacional del Neógeno superior y Cuaternario inferior (Aguirre, E. & Morales, J., Eds.), Libro Guía, pp. 175-212., Ros-Montoya (2010)Ros-Montoya, S. (2010). Los Proboscídeos del Plio-Pleistoceno de las Cuencas de Guadix-Baza y Granada. PhD Thesis, University of Granada, 403 pp. | ||||
| Pantano Cubillas (Granada) | M. meridionalis | Aguirre (1974)Aguirre, E. (1974). Depresión de Granada. In: Coloquio Internacional del Neógeno superior y Cuaternario inferior (Aguirre, E. & Morales, J., Eds.), Libro Guía, pp. 175-212. | ||||
| Cortijo Sabinas (Granada) | M. meridionalis | Ros-Montoya (2010)Ros-Montoya, S. (2010). Los Proboscídeos del Plio-Pleistoceno de las Cuencas de Guadix-Baza y Granada. PhD Thesis, University of Granada, 403 pp. | ||||
| Cortes de Baza (Granada) | M. meridionalis | Aguirre (1958)Aguirre, E. (1958). Novedades paleomastológicas de la Depresión de Granada y estratigrafía de su borde NE. Estudios Geológicos, 14: 107-120. | ||||
| Barranco del Paso (Granada) | M. meridionalis | Gibert et al. (1992)Gibert, J., Arribas, A., Terón, J. & Palomar, J., 1992. Contexto geológico del Barranco del Paso (Orce, Granada). In: Presencia humana en el Pleistoceno inferior de Granada y Murcia. (Gibert, J., Campillo, D., García-Olivares, E., Margosa, A. & Martínez, B., Eds.), Ayuntamiento de Orce, pp. 203-217. | ||||
| Venta Micena (Granada) | M. meridionalis | Palqvist et al. (1996Palmqvist, P., Martínez-Navarro, B. & Arribas, A. (1996). Prey selection by terrestrial carnivores in a lower Pleistocene paleocommunity. Paleobiology, 22: 514-534. https://doi.org/10.1017/S009483730001650X , 2005)Palmqvist, P., Martínez-Navarro, B., Toro, I., Espigares, M.P., Ros-Montoya, S., Torregrosa, V. & Pérez-Claros, J.A. (2005). A re-evaluation of the evidence of human presence during Early Pleistocene times in Southesastern Spain. L’Antropologie, 109: 411-450. https://doi.org/10.1016/j.anthro.2005.06.001 | ||||
| Barranco León (Granada) | M. meridionalis | Martínez-Navarro et al. (2004)Martínez-Navarro, B., Toro, I. & Agustí, J. (2004). Las asociaciones de grandes mamíferos de Fuente Nueva-3 y Barranco León-5 (Orce, Granada, España): Resultados preliminares. Miscelánea Homenaje a Emiliano Aguirre, Museo Arqueológico Regional, Alcalá de Henares, pp. 292-305. | ||||
| Fuente Nueva 3 (Granada) | M. meridionalis | Martínez-Navarro et al. (2003)Martínez-Navarro, B., Espigares, M.P. & Ros, S. (2003). Estudio preliminar de las asociaciones de randes mamíferos de Fuente Nueva-3 y Barranco León-5 (Orce, Granada, España). In: El Pleistoceno inferior de Barranco León y Fuente Nueva 3, Orce (Granada) (Toro, I., Agustí, J. & Martínez-Navarro, B., Eds.), Memoria Científica Campañas 1992-2002. Junta de Andalucía, Consejería de Cultura, Arqueología, pp. 115-136. | ||||
| Huéscar 1 (Granada) | M. meridionalis | Ros-Montoya et al. (2018)Ros-Montoya, S., Palombo, M.R., Espigares, M.P., Palmqvist, P. & Martínez-Navarro, B. (2018). The mammoth from the archaeo-paleontological site of Huéscar-1: A tile in the puzzling question of the replacement of Mammuthus meridionalis by Mammuthus trogontherii in the Early Pleistocene of Europe. Quaternary Science Reviews, 197: 336-351. https://doi.org/10.1016/j.quascirev.2018.08.017 | ||||
| Cúllar Baza 1 (Granada) | M. trongontherii | Alberdi et al. (2001)Alberdi, M.T., Alonso, M.A., Azanza, B., Hoyos, M. & Morales, J. (2001). Vertebrate taphonomy in the circum-lake environments: three cases in the Guadix-Baza Basin (Granada, Spain). Palaeogeography, Palaeoclimatology, Palaeoecology, 165: 1-26. https://doi.org/10.1016/S0031-0182(00)00151-6 | ||||
| Cortijo Daimuz (Granada) | M. trongontherii | Ros-Montoya (2010)Ros-Montoya, S. (2010). Los Proboscídeos del Plio-Pleistoceno de las Cuencas de Guadix-Baza y Granada. PhD Thesis, University of Granada, 403 pp. | ||||
| Solana del Zamborino (Granada) | M. trongontherii and P. antiquus | Martín-Penela (1988)Martín-Penela, A. (1988). Los grandes mamíferos del yacimiento Achelense de la Solana del Zamborino, Fonelas (Granada, España). Antropología y Paleoecología Humana, 5: 29-188., Ros-Montoya (2010)Ros-Montoya, S. (2010). Los Proboscídeos del Plio-Pleistoceno de las Cuencas de Guadix-Baza y Granada. PhD Thesis, University of Granada, 403 pp. | ||||
| Loja (Granada) | P. antiquus | Ros-Montoya (2010)Ros-Montoya, S. (2010). Los Proboscídeos del Plio-Pleistoceno de las Cuencas de Guadix-Baza y Granada. PhD Thesis, University of Granada, 403 pp. | ||||
| Cuadros (Jaén) | P. cf. antiquus | This work | ||||
| Hornachuelos (Córdoba) | P. antiquus | van Made & Mazo (2001)Van der Made, J. & Mazo, A.V. (2001). Spanish Pleistocene Proboscidean diversity as a function of climate. The World of Elephants-International Congress, Rome, pp. 214-218. | ||||
| Almodovar del Río (Córdoba) | P. antiquus | van Made & Mazo (2001)Van der Made, J. & Mazo, A.V. (2001). Spanish Pleistocene Proboscidean diversity as a function of climate. The World of Elephants-International Congress, Rome, pp. 214-218. | ||||
| El Pirulejo (Córdoba) | P. antiquus | Cortés-Sánchez et al. (2017)Cortés-Sánchez, M., Morales-Muñiz, A., Jiménez-Espejo, F., Évora, M., Simón-Vallejo, M.D., García-Alix, A., Martínez Aguirre, A., Riquelme-Cantal, J.A., Odriozola, C.P., Parrilla Giráldez, R. & Álvarez-Lao, D.J. (2017). Multi-purpose fossils? The reappraisal of an Elephas antiquus molar from El Pirulejo (Magdalenian; Córdoba, Spain). Archaeology, Antropology Science, 9: 1287-1303. https://doi.org/10.1007/s12520-016-0324-1 | ||||
| La Rinconada (Sevilla) | P. antiquus | van Made & Mazo (2001)Van der Made, J. & Mazo, A.V. (2001). Spanish Pleistocene Proboscidean diversity as a function of climate. The World of Elephants-International Congress, Rome, pp. 214-218. | ||||
| Jarillas (Sevilla) | P. antiquus | Baena-Escudero et al. (2014)Baena-Escudero, R., Fernández-Caro, J.J., Guerrero-Amador, I. & Posada-Simeon, J.C. (2014). The complex terrace “Las Jarillas” of the Guadalquivir river (La Rinconada, Sevilla, SW of Spain): chronostratigraphy, lithic industry and associated macromammal fauna. Cuaternario y Geomorfología, 28: 107-125. | ||||
| El Padul (Granada) | M. primigenius | Aguirre et al. (1973)Aguirre, E., Lhenaff, R. & Zazo, C. (1973). Nuevos fósiles de elefantes en Andalucía. Estudios Geológicos, 29: 295-306., Álvarez-Lao et al. (2009)Álvarez-Lao, D.J., Kahlke, R.D., García, N. & Mol, D. (2009). The Padul mammoth finds - On the southernmost record of Mammuthus primigenius in Europe and its southern spread during the Late Pleistocene. Palaeogeography, Palaeoclimatology, Palaeoecology, 278: 57-70. https://doi.org/10.1016/j.palaeo.2009.04.011 |
The age of the alluvial fan where the studied tusk remain was recorded is inferred from comparisons with terraces of Guadalquivir and other tributary streams, ranging from 600 to 32 ka (Middle to Late Pleistocene). However, the fact that the record of P. antiquus in South Spain is reported exclusively from the Middle Pleistocene in the Western Guadalquivir Basin, Granada Basin and Guadix-Baza Basin (e.g. Martín-Penela, 1988Martín-Penela, A. (1988). Los grandes mamíferos del yacimiento Achelense de la Solana del Zamborino, Fonelas (Granada, España). Antropología y Paleoecología Humana, 5: 29-188.; Van der Made & Mazo, 2001Van der Made, J. & Mazo, A.V. (2001). Spanish Pleistocene Proboscidean diversity as a function of climate. The World of Elephants-International Congress, Rome, pp. 214-218.; Ros-Montoya, 2010Ros-Montoya, S. (2010). Los Proboscídeos del Plio-Pleistoceno de las Cuencas de Guadix-Baza y Granada. PhD Thesis, University of Granada, 403 pp.; Baena-Escudero et al., 2014Baena-Escudero, R., Fernández-Caro, J.J., Guerrero-Amador, I. & Posada-Simeon, J.C. (2014). The complex terrace “Las Jarillas” of the Guadalquivir river (La Rinconada, Sevilla, SW of Spain): chronostratigraphy, lithic industry and associated macromammal fauna. Cuaternario y Geomorfología, 28: 107-125.) leads us to infer a Middle Pleistocene age for the alluvial fan. Still, we cannot totally discard a Late Pleistocene age for this fossil remain.
Conclusions
⌅This work reports the first record of an elephantidae from the eastern sector of the Guadalquivir foreland Basin (Jaén province). The remain was retrieved from conglomerates deposited in the alluvial fans downslope of the outermost mountain front of the Betic Cordillera, more precisely from Sierra Mágina. These fans developed during the Middle to Late Pleistocene, associated with an intense erosive phase of the young reliefs of the mountain front.
The remain is a fragment of a fossil tusk (74 cm length) associated with high energy detritic sediments ranging from coarse sands to boulders, transported by water streams at the foot of the mountains. The fossil bone is mostly coated by a carbonate-laminated crust (< 2 cm). Its detailed analysis under thin section and SEM evidences a porous laminated fabric of phytal appearance (clusters of multibranched stalks). These structures are interpreted as fossil bryophytes. Therefore, the disarticulated tusk would have been transported and probably fragmented by surficial water streams in a high energy context. The surface of the tusk was covered by mosses that cemented early on. This carbonate crust surrounding part of the tusk favoured its preservation in a high-energy environment, while preservation was likewise aided by fast burial.
The analysis of the Schreger lines in the internal structure of the tusk allows us to assign this remain to the straight-tusked elephant Palaeoloxodon cf. antiquus. This taxon has been reported from the Middle Pleistocene of the Western Guadalquivir Basin (Sevilla and Córdoba provinces) and neighbouring basins such as Granada Basin and Guadix-Baza Basin (Granada province). Consequently, the specimen studied in the southeastern Jaén province (Eastern Guadalquivir Basin) would connect the populations of P. antiquus from the Western Guadalquivir Basin and the Guadix-Baza Basin. Seasonal migrations between low lands of the Western Guadalquivir Basin and high lands of the Guadix-Baza and Granada basins are not discarded.