A new middle Pleistocene (Marine Oxygen Isotope Stage 6

untitledQuaternary Research (2017), 87, 499–515. Copyright © University of Washington. Published by Cambridge University Press, 2017. doi:10.1017/qua.2017.17
A new middle Pleistocene (Marine Oxygen Isotope Stage 6) cold herpetofaunal assemblage from the central Iberian Peninsula (Manzanares Valley, Madrid)
Hugues-Alexandre Blaina,b*, Susana Rubio-Jarac, Joaquín Panerad, David Uribelarreae, César Laplanaf, Esther Herráezg, Alfredo Pérez-Gonzálezd aInstitut Català de Paleoecologia Humana i Evolució Social, Tarragona, Spain bArea de Prehistoria, Universitat Rovira i Virgili, Tarragona, Spain cInstituto de Evolución en África, Madrid, Spain dCentro Nacional de Investigación sobre la Evolución Humana, Burgos, Spain eDepartment of Geodynamics, Complutense University, Madrid, Spain fMuseo Arqueológico Regional de la Comunidad de Madrid, Alcalá de Henares, Spain gGeolineal SL, Hoyo de Manzanares, Madrid, Spain
(RECEIVED April 25, 2016; ACCEPTED January 26, 2017)
Abstract
Middle Pleistocene sites that document glacials are relatively rare in the Iberian Peninsula, and as such, the composition of cold small-vertebrate assemblages is almost unknown in southwestern Mediterranean Europe. The archaeological site Estanque de Tormentas de Butarque H-02 in Villaverde, Madrid, in central Spain, recently attributed to Marine Oxygen Isotope Stage (MIS) 6, provides new data on cold small-vertebrate assemblages. Quantitative climate reconstruction and habitat weighting methods applied to the herpetofaunal assemblage reconstruct the terrestrial climatic and environmental conditions that prevailed in central Spain during the penultimate glacial (MIS 6). During MIS 6, the climate was colder (−3.0°C) and slightly wetter (+122.8mm) than present in the study area. This confirms that temperature variations were not extreme and precipitation was sufficient in southern Mediterranean Europe for the persistence of temperate trees. Paleoenvironmental reconstruction suggests a large representation of dry environments on the overlying plateau, together with a probable corridor of humid meadows and woodlands along the river where the site is located.
Keywords: Amphibians; Reptiles; middle Pleistocene; Penultimate glacial period; Western Mediterranean; Spain
INTRODUCTION
The penultimate glacial period (~185–135 ka) corresponds to Marine Oxygen Isotope Stage (MIS) 6 and to the late Saalian glaciation in Europe (Ehlers et al., 2011). The Saalian glaciation was characterized by two major glacial advances, the more extensive Drenthe followed by the Warthe, both greater in extent than that during the last glacial maximum (Ehlers et al., 2011). Global sea-level reconstructions (Thompson and Goldstein, 2006; Elderfield et al., 2012) indicate a sea-level drop of more than 100m toward the end of MIS 6 (after 150,000 yr). Sea surface temperatures were 5°C lower than present as the climate approached a stable
maximum glacial state, culminating in one of the largest Quaternary glaciations (Margari et al., 2014). Long pollen sequences show that a moderately severe
climate with fluctuating tree abundances prevailed in the early part of MIS 6 in Europe. This was followed by more extreme conditions marked by a mainly treeless landscape in the latest part of MIS 6 (Roucoux et al., 2011). In the late MIS 6, a polar desert existed south of the ice margin, while the rest of Europe was under discontinuous herbaceous plant cover, predominantly Artemisia, chenopods, and grasses (Roucoux et al., 2011). In some sheltered areas of southern Mediter- ranean Europe, scattered temperate tree populations survived in refuges where temperature variations were not extreme and precipitation was sufficient (Bennett et al., 1991; Tzedakis, 1993; Roucoux et al., 2011). A vegetational north–south gradient existed across the Iberian Peninsula, with conifers mainly in the north, whereas deciduous trees were present
*Corresponding author at: Department of Paleontology, Institut Català de Paleoecologia Humana i Evolució Social, Zona Educacional 4, Campus Sescelades URV (Edifici W3), 43007 Tarragona, Spain. E-mail: [email protected] (H.-A. Blain).
499
further south with evergreens in the extreme south and coastal lowlands (Van Andel and Tzedakis, 1996). Only a very few archaeopaleontological sites in south-
western Mediterranean Europe document the terrestrial faunas of the penultimate glacial. MIS 6 is said to have per- mitted the entrance in the Iberian Peninsula across the Strait of Gibraltar because of a much lower sea level and the appearance of temporary islands and some reptiles such as present populations of the snake Malpolon monspessulanus (Carranza et al., 2006), together with the probable first entrance from the north of cold-adapted large mammals such as Coelodonta antiquitatis and Rangifer tarandus (Álvarez-Lao and García-García, 2006, 2010). Small vertebrate studies in southwestern Europe for MIS 6 have been undertaken at Sala de los Huesos in the Cueva de Maltravieso (Extremadura, western Spain; Hanquet, 2011) and the Grotte du Lazaret (Nice, Alpes-Maritimes) and Baume Moula-Guercy (Soyons, Ardèche), both in southeastern France (Lumley et al., 2004; Valensi et al., 2005, 2007; Hanquet et al., 2010; Manzano, 2015). The aim of the present article is to describe the amphibian and reptile fossil remains recovered in site H-02 of Estanque de Tormentas de Butarque (ETB) (Villaverde, Madrid). This allows a precise analysis of their implications for the past climatic and environmental conditions that prevailed in the central Iberian Peninsula during the penultimate glacial.
GEOLOGIC AND CHRONOLOGICAL SETTING
The archaeological sites H-02 and H-03, located in the municipality of Villaverde, south of Madrid, lie within the Complex Terrace of Butarque (CTB; Fig. 1; Goy et al., 1989). The CTB is a unique morphostratigraphic unit composed by various terraces at +12–15 and +18–20m above the present floodplain that have delivered numerous paleontological and archaeological sites in primary position (Pérez-González et al., 2008). The construction of a huge storm-water management reservoir covering and area of 7 ha (~800m long and 600m wide) and a depth of 30m exposed the CTB complete stratigraphic sections that were hundreds of meters in length. This exposed the underlying Miocene interbedded gypsum and clay layers in the fluvial terraces, which offered a unique opportunity to define the complex stratigraphy of this terrace on the Manzanares River and to locate important new archaeological and paleontological sites (De los Arcos Fernández et al., 2008, 2011; Álvarez Catalán et al., 2009). Although the whole deposit is mainly composed of sand, the occurrence of gravel units over disconformities allows three fluvial sequences to be defined. From the base upward, these include ETB 1, ETB 2, and ETB 3 (Fig. 2). These units are affected by synsedimentary and post- sedimentary deformation because of the dissolution and loss of volume of the evaporites in the underlyingMiocene formation. Although the gypsum is dissolved, the clay layers stack upon each other, creating a karstic residue of 3–4m thickness underneath the terrace (Uribelarrea, 2008). The lower units
exhibit the greatest deformation, and all of them are progres- sively tilted toward the west (Silva et al., 2012, 2013). The earliest fluvial sequence (ETB 1) is about 4–5m thick,
with 0.5–0.8m of gravels at the base, 2.5–3m of sand, and 1–2m of overbank sediments on top. Karst processes result in dozens of faults along sequence ETB 1. Site H-03 is in the overbank unit located on top of ETB 1. Although ETB 1 is highly faulted, this layer is traceable for more than 100m. This is important for obtaining a good record of paleontological remains, as H-03 has a low density of fossils. A small number of micromammals and also a greater number of large mammals have been recovered (Laplana et al., 2015). These include three rodents (Arvicola sp., Microtus sp., and Apodemus sp. gr. A. sylvaticus–A. flavicollis), one lagomorph (Oryctolagus cuniculus), two artiodactyls (Cervus elaphus and Bos primigenius), and three perisso- dactyls (Stephanorhinus sp., Equus ferus, and Equus hydruntinus). The sands below H-03 have been dated using thermoluminescence (TL) methods and yield an age of >125 ka (Domínguez Alonso et al., 2009). The middle fluvial sequence, ETB 2, is <1.5m thick and is
composed of a unit of gravels (up to 0.5m), inset into the lower unit ETB 1, creating a wide disconformity. ETB 2 continues with coarse sand grading into laminated clay of overbank origin. Site H-02 is located in the clays at the top of ETB 2 (Domínguez-Alonso et al., 2009) with the largest bones lying in sandy bars below. The whole unit disappears westward (Fig. 2). This unit has been dated on the basis of lithic industries and vertebrate remains (De los Arcos Fernández et al., 2008; Laplana et al., 2015). Large mammal fossils include Canis lupus, Palaeoloxodon antiquus, Stephanorhinus sp., Equus ferus, Equus hydruntinus, Bos primigenius, Bison priscus, Cervus elaphus, and Sus scrofa (De los Arcos Fernández et al., 2008; Álvarez Catalán et al., 2009). Small mammal fossils include Erinaceus sp., Crocidura cf. C. russula, Allocricetus bursae, Arvicola cf. A. sapidus, Microtus arvalis, Microtus brecciensis, Apodemus sp. gr. A. sylvaticus–A. flavicollis, Eliomys quercinus, Oryctolagus cuniculus, and Lepus sp. (Laplana et al., 2015). Laplana et al. (2015) suggest a late middle Pleistocene age (MIS 6) for H-02 (ETB) because of the occurrence of the proboscidean Palaeoloxodon antiquus together with the rodent Microtus brecciensis. P. antiquus is a species present in the middle Pleistocene to early Late Pleistocene terraces of the Manzanares and Jarama Rivers to the southeast of Madrid (Sesé and Soto, 2002a, 2002b). The latest record of M. brecciensis in the Iberian Peninsula is probably from Sala de los Huesos in the Cueva de Maltravieso (Cáceres, western Spain), dated to MIS 6 or, with less probability, to the base of MIS 5 (Hanquet, 2011). Such a chronological interpretation is also supported by the presence ofMicrotus arvalis in H-02 (ETB), a species that has recently appeared in small-mammal associations from other localities of the Jarama and Manzanares River terraces. The record of M. arvalis from H-02 (ETB) may represent the oldest for this species in the area (Laplana et al., 2015). In addition, Laplana et al. (2015) stress that the occurrence in H-02 (ETB)
500 H.-A. Blain et al.
https:/www.cambridge.org/core/terms. https://doi.org/10.1017/qua.2017.17 Downloaded from https:/www.cambridge.org/core. IP address: 213.143.48.57, on 26 May 2017 at 06:28:31, subject to the Cambridge Core terms of use, available at
A new MIS6 herpetofaunal assemblage from Spain 501
of both M. arvalis and Bison priscus suggests cold climatic conditions, later thanMIS 8, documented in other localities in the area such as Valdocarros (Panera et al., 2011; Sesé et al., 2011). Thus, this would constitute an additional argument that H-02 (ETB) formed during MIS 6. The uppermost fluvial sequence, ETB 3, is a complex unit,
composed of a thick succession of fluvial bars, with some gravel channel lenses. Erosion has partially removed the top of ETB 2, so the sandy terms of ETB 2 and ETB 3 merge with each other, making it difficult to establish their limits. The fluvial sequence finishes with a 2-m-thick layer of silts and clays. TL samples taken from the base of ETB 3 and from deposits at 2m and 7m yield ages of 84.6+12.6/−11.2, 74.9+10.2/−9.2, and 56.8±4 ka, respectively (Domínguez Alonso et al., 2009). This corresponds to the end of MIS 5a or the beginning of MIS 4. The upper part of ETB 3 is covered by alluvial fans, fed during the Late Pleistocene by small tributaries from the southwest. Finally, three fluvial incisions partially eroded ETB
(Fig. 2), leaving terraces at +11–12m (40± 4.6 ka), +8–10m (26.7± 2.9 ka), and the Holocene and contemporary floodplain (Domínguez Alonso et al., 2009).
MATERIAL AND METHODS
Systematic paleontology
The paleontological and archaeological material from the site of ETB is stored under registration number 2006/24 in the
collections at the Museo Arqueológico Regional de la Comunidad de Madrid (MAR) in Alcalá de Henares (Madrid, Spain). The amphibian and squamate fossil remains consist mostly of disarticulated elements collected by water screening the sediments obtained during the archaeological excavations at the site of H-02 (ETB) in 2006. Considerable distances separated the samples, and because of this, a minimum number of individuals (MNI) value has been established for each of them. The general taxonomical criteria mainly follow Szyndlar (1984), Bailon (1991, 1999), Gleed-Owen (2000), and Blain (2005, 2009). Comparisons were drawn using the dry skeleton collections from the Museo Nacional de Ciencias Naturales (MNCN, Madrid, Spain) and Blain’s personal collections stored at Institut Català de Paleoecologia Humana i Evolució Social (Tarragona, Spain).
Climatic and environmental reconstructions
Paleoclimatic interpretations are based on the presence of herpetofaunal species from site H-02 (ETB). The quantitative climate reconstruction method mutual climatic range (MCR; Blain et al., 2009) used to help quantify paleotemperatures and paleoprecipitation has recently been proposed under the denomination Universal Transverse Mercator (UTM)–MCR method (Lyman, 2016) and then renamed mutual ecogeographic range (MER; Blain et al., 2016). This does not correspond to MCR methods but more closely resembles the modern analogue technique. The MER method involves
Figure 2. (color online) Complete cross section of the Complex Terrace of Butarque (Estanque de Tormentas de Butarque [ETB]) and the Miocene substratum underneath. Upper right, 3-D image of the storm water management reservoir and the exact position (X, Y, Z) of thermoluminescence (TL) samples. The 3-D image was composed with the satellite image of 2006 and digital terrain model light detection and ranging (resolution = 5m). Source: Consejería de Medio Ambiente y Ordenación del Territorio, Cartografía de la Comunidad de Madrid, and Centro Nacional de Información Geográfica, Instituto Geográfico Nacional.
simply the identification of a geographic region (divided into 10 × 10 km UTM squares) in which all of the species present in a given archaeological level currently live. Ana- lysis of the MER of each archaeological level is based on distribution atlases available for Iberian herpetofauna (Godinho et al., 1999; Pleguezuelos et al., 2004) and various climatic maps of the Iberian Peninsula (Ninyerola et al., 2005). A total of 26 climatic parameters have been calculated for this study. The record from weather station 3182E of Arganda ‘Comunidad’ (Ninyerola et al., 2005), located close to the archaeological locality, has been used for comparison with current data. The habitat weighting method (Blain et al., 2008) has been
used to reconstruct paleoenvironments. This method involves the distribution of each amphibian and reptile taxon into five types of habitat (dry and wet meadows, woodland-edge areas, areas surrounding water, and rocky areas) in accordance to where they are presently found in the Iberian Peninsula (Table 1). Modern data for distribution come from Salvador (1997, 2014), Carrascal and Salvador (2002–2016), García- París et al. (2004), Pleguezuelos et al. (2004), and Masó and Pijoan (2011).
AMPHIBIANS FROM ETB (H-02)
Alytidae: Discoglossus sp.
A painted frog is represented in H-02 by two elements: a right scapula and a right ilium. The scapula is rather short and robust (Fig. 3A). Unfortunately, the acromial apophysis is broken, but the overall shortness of this element is closer to what is observed in the genusDiscoglossus than in the genera Pelodytes and Alytes (Bailon, 1999). The right ilium (Fig. 3B and C) presents a relatively long and slender pars ascendens and an interiliac tubercle typical of the genus Discoglossus,
which is more protruding, as in D. jeanneae, whereas in D. galganoi this tubercle is generally more discrete (López- García et al., 2011). However, these fossils are cautiously ascribed at the genus level only.
Pelobatidae: Pelobates cultripes
With some 76 bone elements, the western spadefoot toad is one of the best-represented anurans in H-02 (ETB; Table 1). The bone assemblage is representative of almost the entire skeleton, although some usually common elements are lacking, such as the ilium. The fossils from H-02 (ETB) comprise two maxillae, eight frontoparietals, one sphe- nethmoid, two squamosals, one vomer, one exoccipital, one parasphenoid, 19 indeterminate cranial fragments with dermal bone ornamentation, one atlas, nine vertebrae, one sacrum, three scapulae, one coracoid, five humeri, one radioulna, three ischio-pubes, 13 tibiofibulae, one tarsal, and one phalanx. Although most of the fossils are markedly incomplete, all of them are very characteristic of this species, in particular some of the cranial elements that present a dense dermal bone ornamentation (i.e., frontoparietals and maxillae). Some of the frontoparietal fragments document a relatively long and pointed processus paraoccipitalis with a distinct ridge running down its dorsal surface and a large squamosal process. The foramen arteriae occipitalis is not visible in dorsal view and is situated more medially with regard to the processus paraoccipitalis, as in P. cultripes (Fig. 3D and E). The vertebrae show a centrum that is procoelous, with a deep and circular anterior cotyle and a robust and round posterior condyle. Typical of the genus, the neural arch is anteroposteriorly long and dorsoventrally flattened, especially in the posterior vertebrae. Additionally, the neural spine is prolonged in a posterior interzygapophyseal tip that in some vertebrae surpasses the posterior edge of the postzygapophyses. The processi transversi are long and
Table 1. Amphibians and squamates from the middle Pleistocene of Estanque de Tormentas de Butarque (ETB; H-02) in number of remains (NR), minimum number of individuals (MNI), percentage (%), and distribution of each taxon in the habitats where they can be found today in the Iberian Peninsula.
H-02 (ETB) Habitat distribution
NR MNI % NR/MNI Open dry Open humid Woodland edge Rocky/stony Water edge
Discoglossus sp. 2 2 2.4 1.0 1 Pelobates cultripes 74 20 24.1 3.8 0.8 0.2 cf. Pelodytes sp. 3 1 1.2 1.0 0.5 0.2 0.1 0.2 Bufo cf. B. spinosus 63 13 15.7 4.8 0.1 0.3 0.4 0.2 Bufo calamita 1 1 1.2 1.0 0.65 0.25 0.1 Pelophylax perezi 106 21 25.3 5.1 1 Anura indet. 5 Emys/Mauremys sp. 4 4 4.8 1.0 1 Lacertidae indet. 22 13 15.7 1.7 Coronella girondica 4 2 2.4 2.0 0.25 0.25 0.25 0.25 Natrix natrix 59 6 7.2 9.8 0.5 0.25 0.25 Total 342 83 100.0 4.1
oriented slightly backward in the only fourth vertebra (V4; Fig. 3F and G). The fossil scapulae are rather robust, are higher than wide, and display a processus glenoidalis that is very distinct from the main corpus of the bone, even though,
in dorsal view, it is partially hidden by the pars acromialis (Fig. 3H). The surface of articulation with the humerus extends onto the processus glenoidalis and the posterior margin of the pars acromialis. The fossil humeri are all
Figure 3. Amphibians from the late middle Pleistocene of Estanque de Tormentas de Butarque H-02 (central Spain). (A–C) Discoglossus sp.: right scapula in dorsal view (A); right ilium in lateral and posterior views (B, C). (D–I) Pelobates cultripes: frontoparietal in dorsal and posterior views (D, E); fourth vertebra in dorsal and anterior views (F, G); left scapula in dorsal view (H); right humerus of female in ventral view (I). (J, K) cf. Pelodytes sp.: sacrum of a juvenile in dorsal view (J); radioulna in lateral view (K). (L–O) Bufo cf. spinosus: left ilium in lateral view (L); left scapula in dorsal view (M); left humerus of male in ventral view (N); femur in ventral view (O). (P) Bufo calamita, left ilium in lateral view. (Q–Z) Pelophylax perezi: right ilium in lateral and posterior views (Q, R); left scapula in dorsal and ventral views (S, T); left humerus of male in ventral and posterior views (U, V); coracoid in dorsal view (W); tibiofibula in lateral view (X); posterior vertebra of a juvenile in dorsal and posterior views (Y, Z). All scales = 2mm.
Pelodytidae: cf. Pelodytes sp.
A probable parsley frog is represented in H-02 (ETB) by very few elements: a sacrum, a radioulna, and a tibiofibula. The only sacrum is small, with an anterior and a posterior cotyle (Fig. 3J). The sacral apophyses are broken but seem to have been strongly dorsoventrally flattened and extended backward, as in the genera Pelobates and Pelodytes (Bailon, 1999). The small size of this element fits better with an attribution to Pelodytes, even if the absence of posterior condyles seems to be a “pathological” characteristic. A small-sized radioulna (Fig. 3K) and a fragment of tibiofibula from H-02 (ETB) are very cautiously referred to the genus Pelodytes. None of the fossils’ features permit an assignation to one of the two species of Pelodytes currently living in the Iberian Peninsula, P. punctatus and P. ibericus.
Bufonidae: Bufo cf. B. spinosus
One exoccipital, one atlas, 14 vertebrae, one sacrum, one urostyle, seven ilia, two ischio-pubes, three scapulae, one coracoid, five humeri, four radioulnae, five femurs, seven tibiofibulae, one tarsal, and 10 phalanxes have been referred to the common toad Bufo spinosus. The ilia are robust without any dorsal crest, and the tuber superior is low, unilobulated, and with a rounded dorsal margin (Fig. 3L). The scapulae (Fig. 3M) are higher than wide and with a robust glenoid process, detached and clearly visible in dorsal view, and without the small supraglenoid fossa usually present in Bufo calamita. The humeri (Fig. 3N) possess a straight diaphysis with a generally weakly ossified and radially displaced humeral condyle. The femurs bear a well-developed femoral crest that bifurcates and creates a triangular surface (Fig. 3O). The other elements display the general morphology of the genus Bufo. Cautious attribution to B. spinosus is possible on the basis of the size and robustness of the remains: B. spinosus generally reaches a larger size than B. bufo and is especially larger than B. calamita. Here we are referring to the size reached by only some of the fossil elements. Among the fossil material from H-02 (ETB), smaller bufonid bones may correspond to younger individuals of B. spinosus.
Bufonidae: Bufo calamita
A left ilium (Fig. 3P) in H-02 (ETB) is attributed to the natterjack toad. Contrary to the previous description of the ilia of B. spinosus, this fossil ilium shows a relatively high and pointed tuber superior characteristic of B. calamita, whereas in B. spinosus and B. bufo the tuber superior is generally low and rounded (Bailon, 1999).
Ranidae: Pelophylax perezi
The Iberian green frog is represented in H-02 (ETB) by 107 bones: one premaxilla, eleven maxillae, one articular sensu lato, one exoccipital, one atlas, 10 vertebrae, one sacrum, four urostyles, three scapulae, three coracoids, one clavicule, one parasternum, 10 humeri, eight radioulnae, eight ilia, three ischio-pubes, one femur, 10 tibiofibulae, and 28 phalanxes. The ilia possess a high and vertical dorsal crest on the anterior branch and a smooth posteromedial face without an interiliac groove (Fig. 3Q and R). The dorsal crest shows a globular and well-differentiated superior tubercle, typical of the genus Pelophylax. The angle between the anterior edge of the superior tubercle and the dorsal edge of the pars ascendens is slightly >90°. The articular surface with the ischium and pubis is relatively thick (ratio of diameter to thickness [d/t] sensu Gleed-Owen [2000] ranging between 2.18 and 2.33 in the H-02 fossils), thus agreeing with the values for Pelophylax (2.12< d/t< 2.88; Gleed-Owen, 2000). The scapulae are distinctly higher than wide and are characterized by a glenoid process that is partially hidden by the acromial process in dorsal view. In ventral view, an internal crest is present on the glenoid process and continues along the bony lamina (Fig. 3S and T). This internal crest is relatively short, as is the case among representatives of Pelophylax, whereas in the genus Rana it is longer (Bailon, 1999). Unlike what is observed in the previously cited genera (Discoglossus, Pelodytes, and Bufo), the humeri possess a straight and robust diaphysis with a generally well-ossified humeral condyle that follows the main axis of the diaphysis (Fig. 3U and V). In male humeri, the mesial crest is generally rather short and oriented transversely to the bone throughout its whole length, whereas in the genus Rana this mesial crest is much longer and more dorsally incurved (Bailon, 1999). The morphology of the other elements matches well with the genus Pelophylax, for example, the tooth-bearing premaxilla and maxillae, the fragment of sacrum with an anterior and two posterior condyles, a nicely preserved coracoid (Fig. 3W), a gracile sigmoid femur without a femoral crest, elongated tibiofibulae with scarcely enlarged extremities (Fig. 3X), and phalanxes that are more elongated and slender than those attributed to bufonids. Some elements, such as the vertebra illustrated in Figure 3Y and Z, are cautiously attributed to a juvenile specimen of Pelophylax. This vertebra is procoelous, with a short neural arch, and the transverse apophyses are not located under the prezygapophyses and are directed transversely. The centrum is rather small, and the lateral walls are thin, as in the genera Rana, Pelophylax, and Hyla.
CHELONIANS FROM ETB (H-02)
Emydidae/Geoemydidae: Emys/Mauremys sp.
Two peripheral plates and various fragments from two indeterminate plates have been recovered from the excavations at H-02 (ETB). They are not as thick as those generally observed in the genus Testudo, and the sulci are not very deep. These remains are referred to an indeterminate aquatic turtle because of their incompleteness, very probably Emys orbicularis or Mauremys leprosa, the only turtles currently living in the Iberian Peninsula (Masó and Pijoan, 2011; Salvador, 2014).
SQUAMATE REPTILES FROM ETB (H-02)
Lacertidae: Lacertidae indet.
A few poorly diagnostic elements have been attributed to lacertid lizards. Two different size categories are represented in the fossils from H-02 (ETB): a medium-size lacertid (three vertebrae, one femur, and one tibia) and a small-size lacertid (two maxillae, six dentaries, one fragment of indeterminate tooth-bearing bone, three vertebrae, one femur, two tibiae, and two hemipelves). Although rather incomplete, all these elements, in particular the maxillae and dentaries, are characteristic of the family Lacertidae. The maxillae and dentaries bear pleurodont, tubular, mainly bicuspid teeth (Fig. 4A and B). In the dentaries, the Meckelian canal is wide open (Fig. 4B). The morphology of the other elements matches well with the family. More precise attribution is hampered by the lack of diagnostic elements. However, the size of the largest vertebra (centrum length = 5.9mm; Fig. 4C and D) falls within the size range of the juveniles or subadults of the largest Iberian species Timon lepidus (currently living in the vicinity of H-02), whereas other smaller elements are more characteristic of the well-distributed Iberian genera Psammodromus and Podarcis.
Colubridae: Natrix natrix
The grass snake N. natrix is represented by a total of 59 elements in H-02 (ETB): two fragments of maxillae, one cervical vertebra, 39 trunk vertebrae, 13 caudal vertebrae, and three fragments of undetermined vertebrae.
The fragments of maxillae have no preserved teeth and represent the posterior part of the element, with a well- preserved ectopterygoid process (Fig. 4I and J). This process is robust in the medial view, wider than long, and somewhat concave, as in N. natrix (Szyndlar, 1984) and to a lesser extent Natrix maura, whereas in other Iberian colubrid genera consulted (Zamenis, Rhinechis,Malpolon, Coronella, and Hemorrhois) it has a different morphology (not so wide) and is rather flat. The trunk vertebrae (centrum length up to 6.8mm; Fig. 4K–N) possess a sigmoid-shaped, short, and strong hypapophysis, and the zygapophyseal articular surfaces are more or less horizontal. The neural arch is vaulted posteriorly, the condyle and cotyle are small and circular, and the parapophysis is provided with a parapophyseal process. In lateral view, the parapophyseal processes are strongly built like in N. natrix (Szyndlar, 1984). The centrum of the trunk vertebrae of N. natrix is generally flat, and its lateral margins are well marked, whereas in N. maura the centrum is slightly convex, with lateral margins that are more or less indistinct (Bailon, 1991).
Colubridae: Coronella girondica
In H-02 (ETB), one cervical and three small-sized (centrum length <3mm) fossil trunk vertebrae, with a typically dorsoventrally flattened neural arch, have been referred to the southern smooth snake C. girondica (Fig. 4F–H). Most of them are broken and show evidence of a high degree of digestion. By contrast with Natrix vertebrae, the trunk vertebrae of Coronella do not bear any hypapophyses on the centrum. For a given size, the trunk vertebrae of C. girondica generally differ from juveniles of Hemorrhois hippocrepis, Rhinechis scalaris, and, to a lesser degree, Malpolon monspessulanus in their more pronounced precondylar constriction (Blain, 2005). Attribution to C. girondica rests on the morphology of the proximal portion of the prezygapophysis (more slender in C. girondica than in C. austriaca) and the relative size of the parapophysis in rela- tion to the diapophysis, in accordance with Szyndlar (1984).
SOME CONSIDERATIONS ON THE H-02 (ETB) HERPETOFAUNAL ASSEMBLAGE
According to Pleguezuelos et al. (2004) and Masó and Pijoan (2011), in the southeastern area of Madrid where H-02 (ETB) is located, there are currently represented one newt (Pleurodeles waltl), seven anurans (Discoglossus galganoi, Pelobates cultripes, Pelodytes punctatus, Bufo spinosus, Bufo calamita, Hyla molleri, and Pelophylax perezi), two endemic chelonians (Emys orbicularis and Mauremys leprosa), eight lizards (Blanus cinereus, Tarentola mauritanica, Chalcides striatus, Acanthodactylus erythrurus, Timon lepidus, Podarcis virescens, Psammodromus algirus, and Psammodromus hispanicus), and four snakes (Natrix maura, Coronella girondica, Rhinechis scalaris, and Malpolon monspessulanus).
In its totality, the herpetofaunal assemblage of H-02 (ETB) documents at least 10 amphibians and reptiles (i.e., 47.6% of the current diversity observed in the southeastern area of Madrid), with six anurans (85.7% of the current diversity), one chelonian (half of the current diversity if only considering autochthonous turtles), one (perhaps two) lizard (14.3% of the current diversity), and two snakes (25.0% of the current diversity). Natrix natrix is the only species represented in
H-02 (ETB) that is currently absent from the area, but it has been mentioned in the middle Pleistocene (MIS 11) of Áridos-1 (Sanchiz and Sanz, 1980; Blain et al., 2014). In comparison with other already published archaeological sites, Arídos-1, Valdocarros II, Preresa, and HAT, in the southeast of Madrid (and mainly corresponding to interglacial periods), H-02 (ETB) is characterized principally by the absence of typical Mediterranean thermophilous taxa
Figure 4. Squamate reptiles from the late middle Pleistocene of Estanque de Tormentas de Butarque H-02 (central Spain). (A–E) Lacertidae indet.: left maxilla in lateral view (A); right dentary in medial view (B); trunk vertebra in dorsal and left lateral views (C, D); tibia in anterior view (E). (F–H) Coronella cf. girondica, trunk vertebra in dorsal, ventral, and posterior views. (I–N) Natrix natrix: left maxilla in ventral and medial views (I, J); trunk vertebra in dorsal, ventral, posterior, and right lateral views (K–N). All scales = 2mm.
PALEOENVIRONMENTAL AND PALEOCLIMATIC RECONSTRUCTIONS
Climate interpreted from fossil amphibians and reptiles
The Madrid region features a continental Mediterranean climate with cold winters because of altitude (700m above sea level), including sporadic snowfalls and minimum temperatures often below freezing. Summer tends to be hot with temperatures that consistently exceed 30°C in July and August and occasionally rise above 40°C. Diurnal ranges are often significant during the summer because of Madrid’s altitude and dry climate. Precipitation, though concentrated
in the autumn and spring, can be observed throughout the year. The climatic data from weather station 3182E (named Arganda ‘Comunidad’) provide us with a reliable record of the current climate in the area close to the archaeological site (Table 2, Fig. 5). The mean annual temperature (MAT) is 13.9°C, and the mean annual precipitation (MAP) is 458.5mm (Ninyerola et al., 2005). The average difference between the warmest and coldest month is 18.8°C. The arid period in summer and the beginning of autumn (from June to September) lasts 4 months. Past climatic parameters were obtained by applying the
MER method to the fossil herpetological assemblage (Table 2). The overlap obtained from the herpetofaunal assemblage of H-02 (ETB) gives 16 UTM squares. These squares occur in north-central and eastern Spain (Fig. 5). The mean value of the estimated MATs is 10.9± 2.3°C (minimum = 8°C; maximum = 15°C), and for the MAPs, it is 581.3± 40.3mm (minimum = 500mm; maximum = 600mm). Climatograms are used in order to better visualize the monthly evolution of temperature (T) and precipitation (P), applying the scale P = 2 × T in order to evaluate directly the Gaussen index (Fig. 5). Finally, the climatic interpretation is synthesized in Table 3. The climate at the time of H-02 (ETB) can be defined as
cold with a very high atmospheric temperature range. The summer is reasonably warm, and the winter is cold. Rainfall is low, even if higher than today, but its distribution is fairly regular with higher amounts during winter and spring. The aridity indexes suggest a semihumid (or humid according to the Dantin-Revenga index), continental Mediterranean (transitional to Oceanic) climate with only two dry months in summer (Fig. 5, Table 3).
Table 2. Climatic parameters calculated (in °C for temperature and mm for precipitation) by the mutual ecogeographic range method for Estanque de Tormentas de Butarque (H-02) and comparison with the climatic values (1970–2001) from the weather station 3182E of Arganda ‘Comunidad’ (Ninyerola et al., 2005). Δ, comparison with present; MAP, mean annual precipitation; MAT, mean annual temperature; N, number of 10 × 10 km Universal Transverse Mercator squares of the overlap; SD, standard deviation.
Month
MAT J F M A M J J A S O N D
Temperature N 16 16 16 16 16 16 16 16 16 16 16 16 16 Mean 10.9 3.1 4.5 6.6 8.9 13.9 18.1 22.4 21.3 17.0 11.7 7.0 4.8 SD 2.3 2.7 3.1 2.4 2.4 1.7 2.2 2.1 3.1 2.9 3.2 2.5 2.3 Minimum 8 0 0 4 6 12 16 20 18 14 8 4 2 Maximum 15 9 10 12 14 18 22 26 26 22 17 12 8 Arganda ‘Comunidad’ 13.9 5.2 6.9 9.7 11.6 15.5 20.6 24 23.7 19.8 14.2 9.1 6.4 Δ −3.0 −2.1 −2.4 −3.1 −2.7 −1.6 −2.5 −1.6 −2.5 −2.8 −2.5 −2.1 −1.7
Precipitation N 16 16 16 16 16 16 16 16 16 16 16 16 16 Mean 581.3 71.3 61.3 49.4 58.8 53.8 43.8 22.5 21.3 37.5 53.1 73.1 86.9 SD 40.3 7.2 10.2 5.7 3.4 8.1 7.2 6.8 8.1 7.7 4.8 4.8 4.8 Minimum 500 60 50 40 50 40 30 10 10 30 50 70 80 Maximum 600 80 70 60 60 70 50 30 30 60 60 80 90 Arganda ‘Comunidad’ 458.5 37.4 45.7 23.7 53 52.9 25.8 11.1 21.2 27.1 44.8 54.5 54.4 Δ 122.8 33.9 15.6 25.7 5.8 0.9 18.0 11.4 0.1 10.4 8.3 18.6 32.5
As stated previously, such results are in accordance with the absence at the site of the typical Mediterranean thermophilous taxa documented in other “warmer” sites (MIS 5, 7, and 11) in the area. However, some Mediterranean taxa, such as Discoglossus sp. and P. cultripes, still survive the cold climate conditions described here, probably by lengthening their period of dormancy.
In comparison with the current climatic data from Arganda ‘Comunidad’ weather station 3182E, the MER-estimated MAT for H-02 (ETB) is much colder (ΔMAT = −3.0°C). The decrease in temperature is in evidence for all the seasons of the year (MTW, mean temperature of the warmest month [May and July] = −1.6°C; MTC, mean temperature of the coldest month [March] = −3.1°C). Although the total amount
Figure 5. (color online) Paleoclimatic reconstruction of Estanque de Tormentas de Butarque (ETB) H-02 according to the mutual ecogeographic range method and comparison with modern data from the weather station 3182E of Arganda ‘Comunidad’ (Ninyerola et al., 2005). To the left: overlap of the current distribution of all the taxa represented as fossils in the site H-02 (ETB) and 10 × 10 km Universal Transverse Mercator (UTM) square corresponding to Arganda ‘Comunidad’. Principal grid comprises 100 × 100 km UTM squares within global UTM zones (from 29T to 31S). To the right: climatograms for H-02 (ETB) and Arganda ‘Comunidad’. MAP, mean annual precipitation; MAT, mean annual temperature; P, precipitation; T, temperature.
Table 3. Climatic interpretation of the climatograms. ETB, Estanque de Tormentas de Butarque. MTC: Mean temperature of the coldest month
Arganda ‘Comunidad’ H-02 (ETB)
Temperature Mean annual temperature 13.9°C Temperate 10.9°C Cold Atmospheric temperature range 18.8°C Very high 19.3°C Very high Summer temperature 2 months >22°C Warm 1 month >22°C Warm Winter temperature MTC = 5.2°C Cold MTC = 3.1°C Cold
Rainfall Mean annual precipitation 458.5mm Low 581.3mm Low Distribution of rainfall Irregular Winter-spring Fairly regular Winter-spring Type of precipitation Rain Rain
Aridity Gaussen index 4 Mediterranean 2 Oceanic Lautensach-Mayer index 4 Semiarid 2 Semihumid Dantin-Revenga index 3.0 Semiarid 1.9 Humid De Martonne index 19.2 Semiarid 27.8 Semihumid
of rainfall is only slightly higher (ΔMAP = +122.8mm) than the current level in Madrid, the rainfall is more regularly distributed throughout the year, reducing the duration of summer aridity. This is clearly suggested by the values of the aridity indexes, which all indicate a semihumid or humid climate for H-02 (ETB), whereas current values are characteristic of a semiarid climate, implying moister conditions in the area during MIS 6 than today. Such a climate pattern is consistent with a glacial period, as has been demonstrated for central Spain (Blain et al., 2012), where during “cold” periods the climate becomes more continental (although preserving some dryness during the summer) by contrast with “warm” periods, where the climate is more temperate (with mild winters and a long period of dryness in summer and early autumn). In accordance with the biochronological interpretation by Laplana et al. (2015) of the morphostratigraphic unit of the CTB that contains the site, H-02 (ETB) can be correlated with a cold and humid phase of MIS 6.
Local environment interpreted on the basis of the fossil amphibians and reptiles
Considering the whole set of amphibians and reptiles (Table 1) represented in H-02 (ETB), some taxa such as C. girondica preferentially live in sunny and rather open biotopes with loose soils and stones. P. cultripes and to a lesser degree Pelodytes sp. and B. calamita are inhabitants of drier open environments, with poor and short plant cover and with loose or stony soils. The considerable representation of B. cf. spinosus (15.7% of the whole assemblage) and N. natrix (7.2%) may indicate the existence of some moister/ cooler forest and woodland-edge environments under reasonably stable climatic conditions. Above all, and because the site is close to the main river, water-edge environments are fairly well represented, with the presence of typical
inhabitants of aquatic biotopes such as Discoglossus sp., P. perezi, Emys/Mauremys, and to a lesser extent N. natrix (altogether representing 50.6% of the whole association). From a taphonomical point of view, almost all the fossil
elements from H-02 (ETB) are fragmentary and seem to have undergone some very short transport (abrasion on bone surfaces). Among the elements, only a few snake vertebrae (C. girondica) present evidence of strong digestion, probably produced by a small carnivore or a diurnal bird of prey. C. girondica is known to be preyed on today by Milvus migrans, Circaetus gallicus, and Buteo buteo (Galán, 2014). When the number of remains (NR)/MNI ratio is taken into account, some species show a higher ratio, such as P. perezi, P. cultripes, B. spinosus, and also N. natrix (Table 1). Because of the proximity of the river, aquatic taxa such as P. perezi are likely to be overrepresented, although others such as Discoglossus and chelonians are not. The relatively high representation of P. cultripes and B. spinosus may be because of the robustness of their bones and perhaps also to the fact that their remains must have come from an “in situ” mortality when buried in loose sediments. Within the fossil material, juveniles of Pelobates and Pelophylax are particu- larly well represented. For N. natrix, the high NR/MNI ratio is presumably because of the difficulty of ascertaining the MNI from vertebrae. When (possibly overrepresented) water taxa are excluded
from our reconstruction (Fig. 6B), the environmental reconstructions based on the H-02 (ETB) herpetofaunal assemblage suggest that during MIS 6 there was a patchy landscape with a large representation of dry meadows (46.0% of the whole environment) on the plateau, followed by what can be interpreted as more local river environments with humid meadows (16.0%), woodlands (17.3%), and aquatic habitats (18.2%). Rocky biotopes are very occasional, representing only 1.2% of the whole environment, probably because of the impossibility of determining the lacertid remains to genus level.
DISCUSSION AND COMPARISONS
Comparison with other H-02 (ETB) proxies
The paleoclimatic and paleoenvironmental reconstructions of the MIS 6 herpetofaunal assemblage of H-02 (ETB) thus characterize a semihumid, cold, continental climate with low but fairly regular precipitation. As a consequence of such climatic conditions (as well as the topography around the site), the overall landscape was rather open with small riverine patches of humid meadows and woodlands. Such reconstructions are in accordance with the list of mammalian species recovered in the site, where the joint occurrence of Microtus arvalis and Bison priscus suggests cold climatic conditions (Laplana et al., 2015). Open environments are well documented by the presence of horses (Equus ferus and Equus hydruntinus), rhinoceros (Stephanorhinus sp.), bison (Bison priscus), and proboscideans (Palaeoloxodon antiquus), as well as by small mammals such as
Figure 6. (color online) Paleoenvironmental reconstruction of Estanque de Tormentas de Butarque H-02 according to the habitat weighting method, with (A) and without (B) water-edge taxa (Discoglossus, Pelophylax perezi, and Emys/Mauremys).
Comparison with other MIS 6 records
In comparison with the last glacial maximum (MIS 2), paleoclimatic reconstructions of the penultimate glacial are rather scarce. In fact, they are limited to a few Antarctic ice cores and marine cores, such as those from the Iberian margin and the Mediterranean Sea (e.g., Petit et al., 1999; de Abreu et al., 2003; Martrat et al., 2004, 2007; Jouzel et al., 2007; Margari et al., 2007, 2010). The geographically closest of these records to H-02 (ETB)
is located on the Portuguese margin (core MD01-2444), where changes in the land-ocean system form a coherent framework with evidence of ice-volume variations during MIS 6. On the basis of the amplitude of millennial-scale variability, the penultimate glacial has been divided by Margari et al. (2014) into three parts: an early part (185–160 ka) with promi- nent oscillations in foraminiferal isotope and tree pollen values (Margari et al., 2010), a transitional period (160–150 ka), and a late part (150–135 ka) with subdued benthic δ18O and δ13C and also Antarctic temperature variations, as well as minimum tree pollen values. The Ioannina Basin (northwestern Greece) is probably the
best terrestrial pollen record for this interval produced to date. Climate reconstructions suggest globally cool and wet conditions (Roucoux et al., 2011; Wilson et al., 2013). At the transition from MIS 7 to MIS 6 (~185,000 yr), temperate tree populations abruptly decline, though with the persistence of taxa such as Corylus, Abies, Carpinus, and Fagus suggesting that mixed deciduous woodland was still present locally. Then, between 177 and 158 ka, temperate tree pollen oscillates between 8% and 45%. However, the total arboreal pollen percentages (77%) during interstadials suggest that the landscape remained relatively open with sparser, less extensive woodlands than during interglacials. Finally, in the later part of MIS 6 (after 155 ka), a greater abundance of steppe taxa and other herbaceous elements, combined with lower tree pollen percentages (mainly between 20% and 40%), indicates that the landscape was predominantly open, in contrast to the earlier part of MIS 6. For the same period, the temperate pollen percentages in MD01-2444 on the Portuguese margin are lower than 10% (Margari et al., 2010, 2014), as at Tenaghi Philippon (Greece; Tzedakis et al., 2003). Such data are also globally corroborated by other types of
information, such as speleothem records. Over continental mid-to-low latitude areas, five speleothem records of early MIS 6 variability can be quoted: the Chinese Hulu/Sanbao
cave record, which yields an impressive resolution back to 224 ka (Cheng et al., 2006; Wang et al., 2008); the eastern Mediterranean record based on the Soreq-Peqi’in record (Ayalon et al., 2002; Bar-Matthews et al., 2003); the Italian Argentarola cave record (Bard et al., 2002); the Gitana cave speleothem record of southeastern Spain (Hodge et al., 2008); and the Villars cave flowstone deposit of southwestern France (Wainer et al., 2013). All of these depict a high- frequency variability involving globally large changes in effective precipitation, with lower rainfall during glacial periods and increased moisture availability during interglacial periods. When compared with MIS 3 and 4, MIS 6 was a cooler and more humid climate, even during the coldest events, with more humid summers detected both in southwestern France and in the Iberian Peninsula. With regard to temperature and precipitation quantifica-
tions, several different reconstructions have concluded that the climate of at least some intervals in early MIS 6 must have been characterized by temperature depressions (summer and annual) of 8–9°C below modern values and annual precipitation of >2000mm (and possibly >3000mm) in the highest mountains in order to form the glaciers (Hughes et al., 2007; Hughes and Braithwaite, 2008). Long pollen sequences from France have also yielded estimates of MATs and MAPs (Guiot et al., 1989, 1993). At La Grande Pile (Vosges), the annual temperature was 4 to 8°C lower and precipitation 200 to 800mm lower than at present in the area. In south-central France, reconstructions for the Les Echets area suggest an MAT 8 to 12°C lower and precipitation 400 to 600mm less than today. Such results have also been corroborated by the coleopteran assemblage studies in La Grande Pile, with a cold and very continental reconstructed climate for the later part of MIS 6 (Ponel, 1995). In southwestern Europe, only a few archaeological sites
have been reported relating toMIS 6. This is the case with Sala de los Huesos in the Cueva de Maltravieso (Cáceres, western Spain), dated to within MIS 6 or the base of MIS 5. The mammalian faunal list and overall environmental reconstructions made by Hanquet (2011) for this site are roughly similar to those for H-02 (ETB), suggesting a locally humid and wooded environment within a larger open and dry landscape. The climate is described as having been colder and drier (but still humid) than presently in the area. However, the thermophilous bats (Rhinolophus euryale, Rhinolophus mehelyi, Rhinolophus ferrumequinum, and Miniopterus schreibersi) and reptiles (Malpolon monspessulanus, Timon lepidus, and Rhinechis sp.; S. Bailon in Hanquet, 2011) in Sala de los Huesos indicate much warmer conditions than in H-02 (ETB), where such taxa (especially reptiles) have not been documented. The persistence of Mediterranean thermophilous species is probably a characteristic of the Maltravieso area during cold stages, as documented by Bañuls Cardona et al. (2012, 2014) during the last glacial maximum (MIS 2) in the archaeological site of Sala de las Chimeneas in the Cueva de Maltravieso (Cáceres, western Spain). Finally, two other sites in southeastern France have docu-
mented parts of the MIS 6. The Grotte du Lazaret (Nice,
herpetofaunal assemblage from H-02 (ETB) suggest that, apart from the much drier conditions observed in northern continental Europe (from temperature and precipitation estimates for La Grande Pile and Les Echets pollen sequences), temperature variations were not extreme, and precipitation was sufficient in some areas of southern Mediterranean Europe to permit the persistence of temperate tree populations and some Mediterranean anurans. Apart from these general considerations, the lack of chronological precision for H-02 (ETB) hampers more detailed comparison with the climate variability observed during MIS 6. However, comparison with the Grotte du Lazaret small-vertebrate assemblages does suggest a greater similarity with stage 6.2 (as defined by Imbrie et al., 1984) or lettered stage 6a (see Railsback et al., 2015), by the absence of typical Mediterranean thermophilous reptiles at H-02 (ETB), the oceanic cold and slightly humid reconstructed climate, and its associated open-dry landscape.
CONCLUSIONS
The fossil amphibians and reptiles from the middle Pleistocene archaeological site of ETB (H-02), stored in the
collections at the MAR, have been described and quantified for the first time. This has enabled us to produce a precise interpretation for the climatic and environmental conditions that prevailed in the central Iberian Peninsula during MIS 6, one of the coldest glacial periods of the Pleistocene, some 150,000 yr ago. We conclude the following points. The herpetofaunal assemblage from H-02 (ETB) is com-
posed of at least 10 amphibians and reptiles (i.e., 37.5% of the current diversity observed in the southeastern area of Madrid): six anurans (Discoglossus sp., Pelobates cultripes, cf. Pelodytes sp., Bufo cf. B. spinosus, Bufo calamita, and Pelophylax perezi), one turtle (Emys or Mauremys), one or two indeterminate lizards (Lacertidae indet.), and two snakes (Natrix natrix and Coronella girondica). Natrix natrix is the only species represented in H-02 (ETB) that is currently absent from the area. In comparison with the other archaeological sites from the
southeast of Madrid (and mainly corresponding to interglacials), the herpetofaunal association from H-02 (ETB) is characterized by a regional impoverishment of the squamate thermophilous fauna, whereas the anuran diversity remains similar to that at present. Another interesting observation is the absence of any typical cold Euro-Siberian or higher- altitude species in H-02 (ETB). Finally, some currently restricted Mediterranean species (Discoglossus and P. cultripes) demonstrate here their ability to adapt locally to colder conditions. The climate during MIS 6 was colder and slightly wetter
than today in central Spain, with an MAT 3.0°C lower and an MAP 122.8mm higher than at present in the area. The temperature decrease is higher for winter/spring (ΔMTC = −3.1°C; with an MTC occurring in March instead of January) than for summer (ΔMTW = −1.6°C), which remains reasonably temperate. The slightly higher reconstructed rainfall is well distributed throughout the whole year, with the highest amount during winter, the period of dryness during summer thus lasting much less than today. In comparison with other localities, from central Spain,
such a cold and continental climate (with a reduced period of aridity during the summer) is consistent with a glacial. In accordance with the biochronological interpretation by Laplana et al. (2015) and the numeric TL age (>125 ka) obtained for the underlying sedimentary sequence, H-02 (ETB) can be correlated with a cold and semihumid period of MIS 6, maybe the MIS 6a. The climate reconstructions from H-02 (ETB) also suggest
that MIS 6 may have preserved some moisture in southern- most Europe, favorable to the persistence of small woodland areas by contrast with the severe quantitative climate reconstructions obtained in northern no-Mediterranean pollen sequences (such as Les Echets and La Grande Pile). Finally, the environmental reconstructions based on the
herpetofaunal assemblage suggest that during MIS 6 there was a large representation of dry environments on the overlying plateau, together with a probable corridor of humid meadows and woodlands along the river, where the site is located.
REFERENCES
Álvarez Catalán, V., De los Arcos Fernández, S., Gallego Lletjos, N., Gil Ortiz, C., González García, I., Herráez Igualador, E., Ruiz Zapata, B., Yravedra Sanz de los Terreros, J., 2009. Yacimiento Paleolítico del Estanque de Tormentas de Butarque. 718-05-H-02. In: Benet Jordana, N., Benito, J.E. (Eds.), Actas de las Cuartas Jornadas de Patrimonio Arqueológico en la Comunidad de Madrid. Dirección General de Patrimonio Histórico. Área de Promoción y Difusión, Madrid, pp. 333–338.
Álvarez-Lao, D., García-García, N., 2006. A new site from the Spanish Middle Pleistocene with cold-resistant faunal elements: La Parte (Asturias, Spain). Quaternary International 142–143, 107–118.
Álvarez-Lao, D., García-García, N., 2010. Chronological distribution of Pleistocene cold-adapted large mammal faunas in the Iberian Peninsula. Quaternary International 212, 120–128.
Ayalon, A., Bar-Matthews, M., Kaufman, A., 2002. Climatic conditions during Marine Isotope Stage 6 in the eastern Mediterranean region from the isotopic composition of speleothems of Soreq Cave, Israel. Geology 30, 303–306.
Bailon, S., 1991. Amphibiens et reptiles du Pliocène et du Quaternaire de France et d’Espagne: mise en place et évolution des faunes. PhD dissertation, Université de Paris VII, Paris.
Bailon, S., 1999. Différenciation ostéologique des Anoures (Amphi- bia, Anura) de France. Fiches d’ostéologie animale pour l’archéo- logie, Série C: Varia, No. 1. Association pour la promotion et la diffusion des connaissances en archeologie, Antibes, France.
Bañuls Cardona, S., López-García, J.M., Blain, H.-A., Canals Salomó, T., 2012. Climate and landscape during the Last Glacial Maximum in southwestern Iberia: the small-vertebrate assemblage from Sala de las Chimeneas, Cueva de Maltravieso (Cáceres, Extremadura). Comptes Rendus Palevol 11, 31–40.
Bañuls Cardona, S., López-García, J.M., Blain, H.-A., Lozano- Fernández, I., Cuenca-Bescós, G., 2014. The end of the Last Glacial Maximum in the Iberian Peninsula characterized by the small- mammal assemblages. Journal of Iberian Geology 40, 19–27.
Bard, E., Delaygue, G., Rostek, F., Antonioli, F., Silenzi, S., Schrag, D.P., 2002. Hydrological conditions over the western Mediterra- nean basin during the deposition of the cold Sapropel 6 (ca. 175 kyr BP). Earth and Planetary Science Letters 202, 481–494.
Bar-Matthews, M., Ayalon, A., Gilmour, M., Matthews, A., Hawkesworth, C.J., 2003. Sea-land oxygen isotopic relationships from planktonic foraminifera and speleothems in the Eastern Mediterranean region and their implication for paleorainfall during interglacial intervals. Geochimica et Cosmochimica Acta 67, 3181–3199.
Bennett, K., Tzedakis, P.C., Willis, K., 1991. Quaternary refugia of north European trees. Journal of Biogeography 18, 103–115.
Blain, H.-A., 2005. Contribution de la paléoherpétofaune (Amphibia & Squamata) à la connaissance de l’évolution du climat et du paysage du Pliocène supérieur au Pléistocène moyen d’Espagne. PhD dissertation, Muséum National d’Histoire Naturelle de Paris, Paris.
Blain, H.-A., 2009. Contribution de la paléoherpétofaune (Amphibia & Squamata) à la connaissance de l’évolution du climat et du paysage du Pliocène supérieur au Pléistocène moyen d’Espagne. Treballs del Museo de Geología de Barcelona 16, 39–170.
Blain, H.-A., Bailon, S., Cuenca-Bescós, G., 2008. The Early–Middle Pleistocene palaeoenvironmental change based on the squamate reptile and amphibian proxy at the GranDolina site, Atapuerca, Spain. Palaeogeography, Palaeoclimatology, Palaeoecology 261, 177–192.
Blain, H.-A., Bailon, S., Cuenca-Bescós, G., Arsuaga, J.L., Bermúdez de Castro, J.M., Carbonell, E., 2009. Long-term climate record inferred from early-middle Pleistocene amphibian and squamate reptile assemblages at the Gran Dolina cave, Atapuerca, Spain. Journal of Human Evolution 56, 55–65.
Blain, H.-A., Lozano-Fernández, I., Agustí, J., Bailon, S., Menéndez, L., Espígares Ortiz, M.P., Ros-Montoya, S., et al., 2016. Refining upon the climatic background of the Early Pleistocene hominid settlement in western Europe: Barranco León and Fuente Nueva-3 (Guadix-Baza basin, SE Spain). Quaternary Science Reviews 144, 132–144.
Blain, H.-A., Panera, J., Uribelarrea, D., Rubio-Jara, S., Pérez-González, A., 2012. Characterization of a rapid climate shift at the MIS 8/7 transition in central Spain (Valdocarros II, Autonomous Region of Madrid) by means of the herpetological assemblages. Quaternary Science Reviews 47, 73–81.
Blain, H.-A., Santonja, M., Pérez-González, A., Panera, J., Rubio-Jara, S., 2014. Climate and environments during Marine Isotope Stage 11 in the central Iberian Peninsula: the herpetofaunal assemblage from the Acheulean site of Áridos-1, Madrid. Quaternary Science Reviews 94, 7–21.
Blain, H.-A., Sesé, C., Rubio-Jara, S., Panera, J., Uribelarrea, D., Pérez-González, A., 2013. Reconstitution paléoenvironnementale et paléoclimatique du Pléistocène supérieur ancien (MIS 5a) dans le Centre de l’Espagne: les petits vertébrés (Amphibia, Reptilia & Mammalia) des gisements de HAT et PRERESA (Sud-est de Madrid). Quaternaire 24, 191–205.
Carranza, S., Arnold, E.N., Pleguezuelos, J.M., 2006. Phylogeny, biogeography and evolution of two Mediterranean snakes, Malpolon monspessulanus and Hemorrhois hippocrepis (Squamata, Colubridae), using mtDNA sequences. Molecular Phylogenetics and Evolution 40, 532–546.
Carrascal, L.M., Salvador, A. (Eds.), 2002–2016. Enciclopedia Virtual de los Vertebrados Españoles. MuseoNacional de Ciencias Naturales, Madrid. http://www.vertebradosibericos.org.
Cheng, H., Edwards, R.L.,Wang, Y., Kong, X., Ming, Y., Kelly, M.J., Wang, X., Gallup, C.D., Liu, W., 2006. A penultimate glacial monsoon record from Hulu Cave and two phase glacial termina- tions. Geology 34, 217–220.
de Abreu, L., Shackleton, N., Schönfeld, J., Hall, M., Chapman, M., 2003. Millennial-scale oceanic climate variability off the western Iberian margin during the last two glacial periods. Marine Geology 196, 1–20.
De los Arcos Fernández, S., Gallego, N., Gil, C., González, I., Yravedra, J., 2011. El nivel 4 (arcillas) del yacimiento paleolítico del Estanque de Tormentas de Butarque (Villaverde, Madrid). In: Santonja, M. (Ed.), Actas de las Quintas Jornadas de Patrimonio Arqueológico en la Comunidad deMadrid. Communidad deMadrid. Dirección General de Patrimonio Histórico, Madrid, pp. 323–327.
Desclaux, E., Defleur, A., 1997. Étude préliminaire des micromammi- fères de la Baume Moula-Guercy à Soyons (Ardèche, France). Systé- matique, biostratigraphie et paléoécologie. Quaternaire 8, 213–223.
Domínguez Alonso, R.M., De los Arcos Fernández, S., Ruiz-Zapata, B., Gil-García, M.J., 2009. Nuevos datos sobre la Terraza Compleja de Butarque en Villaverde Bajo. In: Benet Jordana, N., Benito, J.E. (Eds.), Actas de las Cuartas Jornadas de Patrimonio Arqueológico en la Comunidad de Madrid. Dirección General de Patrimonio Histórico. Área de Promoción y Difusión, Madrid, pp. 339–344.
Ehlers, J., Grube, A., Stephan, H.-J., Wansa, S., 2011. Pleistocene glaciations of North Germany—new results. In: Ehlers, J., Gibbard, P. L., Hughes, P.D. (Eds.), Quaternary Glaciations - Extent and Chronology: A Closer Look. Developments in Quaternary Sciences. Vol. 15. Elsevier, Amsterdam, pp. 149–162.
Elderfield, H., Ferretti, G., Greaves, M., Crowhurst, S., McCave, I.N., Hodell, D., Piotrowski, A.M., 2012. Evolution of ocean temperature and ice-volume through the Mid-Pleistocene Climate Transition. Science 337, 704–709.
Foury, Y., Desclaux, E., Daujeard, C., Defleur, A., Moncel, M.-H., Raynal, J.-P., 2016. Évolution des faunes de rongeurs en moyenne Vallée du Rhône (Rive droite, Ardèche, France) au tours du Pléistocène moyen final et du Pléistocène supérieur ancien, du MIS 6 au MIS 4. Quaternaire 27, 55–79.
Galán, P., 2014. Coronella girondica (Daudin, 1803). In: Salvador, A. (Ed.), Fauna Ibérica. Vol. 10. Reptiles (2a edición, revisada y aumentada). Consejo Superior de Investigationes Científicas, Madrid, pp. 706–721.
García-París, M., Montori, A., Herrero, P., 2004. Fauna Ibérica. Vol. 24, Amphibia: Lissamphibia. Consejo Superior de Investiga- tiones Científicas, Madrid.
Gleed-Owen, C.P., 2000. Subfossil records of Rana cf. lessonae, Rana arvalis and Rana cf. dalmatina from Middle Saxon (c. 600- 950 AD) deposits in eastern England: evidence for native status. Amphibia-Reptilia 21, 57–65.
Godinho, R., Teixeira, J., Rebelo, R., Segurado, P., Loureiro, A., Álvares, F., Gomes, N., Cardoso, P., Camilo-Alves, C., Brito, J.C., 1999. Atlas of the continental Portuguese herpetofauna: an assemblage of published and new data. Revista Española de Herpetología 13, 61–82.
Goy, J.L., Pérez-González, A., Zazo, C., 1989. Cartografía y Memoria del Cuaternario y Geomorfología, Hoja de Madrid (559). Mapa Geológico de España. Escala 1:50.000. 2ª Serie (MAGNA). Instituto Geológico y Minero de España, Madrid.
Guiot, J., de Beaulieu, J.L., Cheddadi, R., David, F., Ponel, P., Reille,M., 1993. The climate inwestern Europe during the last glacial/interglacial cycle derived from pollen and insect remains. Palaeogeography, Palaeoclimatology, Palaeoecology 103, 73–94.
Guiot, J., Pons, A., de Beaulieu, J.L., Reille, M., 1989. A 140,000-year continental climate reconstruction from two European pollen records. Nature 338, 309–313.
Hanquet, C., 2011. Évolution des paléoenvironnements et des paléoclimats au Pléistocène moyen, en Europe méridionale, d’après les faunes de micromammifères. PhD dissertation, Université Montpellier III - Paul Valéry, Montpellier, France.
Hanquet, C., Valensi, P., Bailon, S., Desclaux, E., El Guennouni, K., Roger, T., de Lumley, H., 2010. Caractérisation du climat et de la biodiversité au Pléistocène moyen final, d’après les faunes de vertébrés de la grotte du Lazaret. Quaternaire 21, 215–226.
Hodge, E.J., Richards, D.A., Smart, P.L., Andreo, B., Hoffmann, D.L., Mattey, D.P., González-Ramón, A., 2008. Effective precipitation in southern Spain (similar to 266 to 46 ka) based on a speleothem stable carbon isotope record. Quaternary Research 69, 447–457.
Hughes, P.D., Braithwaite, R.J., 2008. Application of a degree-day model to reconstruct Pleistocene glacial climates. Quaternary Research 69, 110–116.
Hughes, P.D., Woodward, J.C., Gibbard, P.L., 2007. Middle Pleisto- cene cold stage climates in theMediterranean: new evidence from the glacial record. Earth and Planetary Science Letters 253, 50–56.
Imbrie, J., Hays, J.D., Martinson, D.G., McIntyre, A., Mix, A.C., Morley, J.J., Pisias, N.G., Prell, W.L., Shackleton, N.J., 1984. The orbital theory of Pleistocene climate: support from a revised chronology of the marine δ18O record. In: Berger, A.L., Imbrie, J., Hays, J., Kukla, G., Saltzman, B. (Eds.), Milankovitch and Climate: Understanding the Response to Astronomical Forcing. Part 1. D. Reidel, Dordrecht, the Netherlands, pp. 269–305.
Jouzel, J., Masson-Delmotte, V., Cattani, O., Dreyfus, G., Falourd, S., Hoffmann, G., Minster, B., et al., 2007. Orbital and millennial Antarctic climate variability over the past 800,000 years. Science 317, 793–796.
Laplana, C., Herráez, E., Yravedra Saínz de los Terreros, J., Bárez, S., Rubio-Jara, S., Panera, J., Rus, I., Pérez-González, A., 2015. Biocronología de la Terraza Compleja de Butarque del río Manzanares en el Estanque de Tormentas al sur de Madrid (España). Estudios Geológicos 71, e028. http://dx.doi.org/ 10.3989/egeol.41808.338.
López-García, J.M., Blain, H.-A., Cuenca-Bescós, G., Alonso, C., Alonso, S., Vaquero, M., 2011. Small vertebrates (Amphibia, Squamata, Mammalia) from the late Pleistocene-Holocene of Valdavara-1 cave (Galicia, northwestern Spain). Geobios 44, 253–269.
Lumley, H., de, Echassoux, A., Bailon, S., Cauche, D., Marchi, M.-P., de, Desclaux, E., El Guennouni, K., et al., 2004. Le sol d’occupation acheuléen de l’unité archéostratigraphique UA 25 de la grotte du Lazaret: Nice, Alpes-Maritimes. Edisud, Aix-en-Provence, France.
Lyman, R.L., 2016. The mutual climatic range technique is (usually) not the area of sympatry technique when reconstructing paleoenvironments based on faunal remains. Palaeogeography, Palaeoclimatology, Palaeoecology 454, 75–81.
Manzano, A., 2015. Les amphibiens et les reptiles des sites Pléistocène moyen et supérieur de la France méditerranéenne (Caune de l’Arago, grotte du Lazaret et Baume Moula-Guercy). Étude systématique, reconstitutions paléoclimatiques et paléo- environnementales. PhD dissertation, Université de Perpignan Via Domitia, Perpignan, France.
Margari, V., Skinner, L.C., Hodell, D.A., Martrat, B., Toucanne, S., Grimalt, J.O., Gibbard, P.L., Lunkka, J.P., Tzedakis, P.C., 2014. Land-ocean changes on orbital and millennial timescales and the penultimate glaciation. Geology 42, 183–186.
Margari, V., Skinner, L.C., Tzedakis, P.C., Ganopolski, A., Vautravers, M., Shackleton, N.J., 2010. The nature of millennial-scale climate variability during the past two glacial periods. Nature Geoscience 3, 127–133.
Margari, V., Tzedakis, P.C., Shackleton, N.J., Vautravers, M., 2007. Vegetation response in SW Iberia to abrupt climate change during MIS 6: direct land-sea comparisons. Quaternary International 167–168, Supplement, 267–268.
Martrat, B., Grimalt, J.O., Lopez-Martinez, C., Cacho, I., Sierro, F.J., Flores, J.A., Zahn, R., Canals, M., Curtis, J.H., Hodell, D.A., 2004. Abrupt temperature changes in the western Mediterranean over the past 250,000 years. Science 306, 1762–1765.
Martrat, B., Grimalt, J.O., Shackleton, N.J., de Abreu, L., Hutterli, M.A., Stocker, T.F., 2007. Four climate cycles of recurring deep and surface water destabilizations on the Iberian margin. Science 317, 502–507.
Masó, A., Pijoan, M., 2011. Anfibios y Reptiles de la Península ibérica, Baleares y Canarias. Ediciones Omega, Barcelona, Spain.
Ninyerola, M., Pons, X., Roure, J.M., 2005. Atlas Climático Digital de la Península Ibérica. Metodología y Aplicaciones en Bioclimatología y Geobotánica. Universidad Autónoma de Barcelona, Bellaterra, Spain.
Panera, J., Torres, T., Pérez-González, A., Ortiz, J.E., Rubio-Jara, S., Uribelarrea del Val, D., 2011. Geocronología de la Terraza Compleja de Arganda en el valle del río Jarama (Madrid, España). Estudios Geológicos 67, 495–504.
Pérez-González, A., Rubio Jara, S., Panera, J., Uribelarrea, D., 2008. Geocronología de la sucesión arqueoestratigráfica de Los Estragales en la Terraza Compleja de Butarque (Valle del río Manzanares, Madrid). Geogaceta 45, 39–42.
Petit, J.R., Jouzel, J., Raynaud, D., Barkov, N.I., Barnola, J.-M., Basile, I., Bender, M., et al., 1999. Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature 399, 429–436.
Pleguezuelos, J.M., Márquez, M., Lizana, M., 2004. Atlas y Libro Rojo de los Anfibios y Reptiles de España. Dirección General de Conservación de la Naturaleza. Asociación Herpetologica Española, Madrid.
Ponel, P., 1995. Rissian, Eemian and Wurmian Coleoptera assemblages from La Grande Pile (Vosges, France). Palaeo- geography, Palaeoclimatology, Palaeoecology 114, 1–41.
Railsback, L.B., Gibbard, P.L., Head, M.J., Voarintsoa, N.R.G., Toucanne, S., 2015. An optimized scheme of lettered marine isotope substages for the last 1.0 million years, and the climatostratigraphic nature of isotope stages and substages. Quaternary Science Reviews 111, 94–106.
Roucoux, K.H., Tzedakis, P.C., Lawson, I.T., Margari, V., 2011. Vegetation history of the penultimate glacial period (Marine Isotope Stage 6) at Ioannina, north-west Greece. Journal of Quaternary Science 26, 616–626.
Salvador, A. (Ed.), 1997. Fauna Ibérica. Vol. 10, Reptiles. Museo Nacional de Ciencias Naturales, Madrid.
Salvador, A. (Ed.), 2014. Fauna Ibérica. Vol. 10, Reptiles (2a
edición, revisada y aumentada). Consejo Superior de Investiga- tiones Científicas, Madrid.
Sanchíz, F.B., Sanz, J.L., 1980. Los anfibios del Pleistocenomedio de Áridos-1 (Arganda,Madrid). In: Santonja, M., LópezMartínez, N., Pérez-González, A. (Eds.), Ocupaciones achelenses en el Valle del Jarama. Publicaciones de la Excelentísima Diputación Provincial de Madrid, Madrid, pp. 105–126.
Sesé, C., Soto, E., 2002a. Catálogo de los yacimientos de Vertebrados del Pleistoceno en las terrazas de los ríos Jarama y Manzanares. In: Panera, J., Rubio Jara, S. (Eds.), Bifaces y elefantes. La investigación del Paleolítico Inferior en Madrid. Zona Arqueológica 1, 430–457.
Sesé, C., Soto, E., 2002b. Vertebrados del Pleistoceno del Jarama y Manzanares. In: Panera, J., Rubio Jara, S. (Eds.), Bifaces y elefantes. La investigación del Paleolítico Inferior en Madrid, Zona Arqueológica 1, 318–337.
Sesé, C., Panera, J., Rubio-Jara, S., Pérez-González, A., 2011. Micromamíferos del PleistocenoMedio y Pleistoceno Superior en
el Valle del Jarama: yacimientos de Valdocarros y HAT (Madrid, España). Estudios Geológicos 67, 131–151.
Silva, P.G., López-Recio, M., Cuartero, F., Baena, J., Tapias, F., Manzano, I., Martin, D., Morín de Pablos, J., Roquero, E., 2012. Geomorphological setting and main technological features of new Middle and Upper Pleistocene sites in the Lower Manzanares River Valley (Madrid, Spain). Estudios Geológicos 68, 57–89.
Silva, P.G., López-Recio, M., Tapias, F., Roquero, E., Morín de Pablos, J., Rus, I., Carrasco-García, P., Giner-Robles, J.L., Rodríguez-Pascua, M.A., Pérez-López, R., 2013. Stratigraphy of the Arriaga Palaeolithic sites. Implications for the geomorphological evolution recorded by thickened fluvial sequences within the Manzanares River valley (Madrid Neogene Basin, central Spain). Geomorphology 196, 138–161.
Szyndlar, Z., 1984. Fossil Snakes from Poland. Acta Zoologica Cracoviensia 28. Pánstwowe Wydawnictwo Naukowe, Warsaw.
Thompson,W.G., Goldstein, S.L., 2006. A radiometric calibration of the SPECMAP timescale. Quaternary Science Reviews 25, 3207–3215.
Tzedakis, P.C., 1993. Long-term tree populations in northwest Greece through multiple Quaternary climate cycles. Nature 364, 437–440.
Tzedakis, P.C., McManus, J.F., Hooghiemstra, H., Oppo, D.W., Wijmstra, T.A., 2003. Comparison of changes in vegetation in northeast Greece with records of climate variability on orbital and suborbital frequencies over the last 450,000 years. Earth and Planetary Science Letters 212, 197–212.
Uribelarrea, D., 2008. Dinámica y evolución de las llanuras aluviales de los ríos Manzanares, Jarama y Tajo, entre las ciudades de Madrid y Toledo. PhD dissertation, Departamento de Geodinámica, Facultad de Ciencias Geológicas, Universidad Complutense de Madrid, Madrid.
Valensi, P., Aouraghe, H., Bailon, S., Cauche, D., Combier, J., Desclaux, E., Gagnepain, J., et al., 2005. Les peuplements préhistoriques dans le Sud-Est de la France à la fin du Pléistocène moyen: 400 - 120 000 ans. Terra Amta, Orgnac 3, Baume Bonne, Lazaret. Cadre géochronologique et biostratigraphique, paléo- environnements et évolution culturelle des derniers anténeander- taliens. In: Tuffreau, A. (Ed.), Peuplements humains et variations environnementales au Quaternaire, Colloque de Poitiers (18-20 septembre 2000). British Archaeological Reports International Series 1352. John and Erica Hedges. Oxford, UK, pp. 33–37.
Valensi, P., Bailon, S., Michel, V., Desclaux, E., Rousseau, L., Genty, D., Blamart, D., Onoratini, G., Lumley, H., 2007. Cadre climatique et environnemental des acheuléens de la grotte du Lazaret, à Nice. Données paléontologiques, biochimiques et radiométriques établies sur les faunes de vertébrés et d’inverté- brés. ArchéoSciences, Révue d’Archéométrie 31, 137–150.
Van Andel, T.H., Tzedakis, P.C., 1996. Palaeolithic landscapes of Europe and environs, 150,000-25,000 years ago: an overview. Quaternary Science Reviews 15, 481–500.
Wainer, K., Genty, D., Blamart, D., Bar-Matthews, M., Quinif, Y., Plagnes, V., 2013. Millennial climatic instability during penultimate glacial period recorded on a south-western France speleothem. Palaeogeography, Palaeoclimatology, Palaeo- ecology 376, 122–131.
Wang, Y., Cheng, H., Edwards, R.L., Kong, X., Shao, X., Chen, S., Wu, J., Jiang, X., Wang, X., An, Z., 2008. Millennial- and orbital- scale changes in the East Asian monsoon over the past 224,000 years. Nature 451, 1090–1093.
Wilson, G.P., Frogley, M.R., Roucoux, K.H., Jones, T.D., Leng, M.J., Lawson, I.T., Hughes, P.D., 2013. Limnetic and terrestrial responses to climate change during the onset of the penultimate glacial stage in NW Greece. Global and Planetary Change 107, 213–225.
INTRODUCTION
Figure 1(color online) Geographic and geologic location of the middle Pleistocene archaeological site of Estanque de Tormentas de Butarque (Madrid, central Spain).
MATERIAL AND METHODS
Climatic and environmental reconstructions
Figure 2(color online) Complete cross section of the Complex Terrace of Butarque (Estanque de Tormentas de Butarque [ETB]) and the Miocene substratum underneath.
AMPHIBIANS FROM ETB (H-02)
Alytidae: Discoglossus sp
Pelobatidae: Pelobates cultripes
Table 1Amphibians and squamates from the middle Pleistocene of Estanque de Tormentas de Butarque (ETB; H-02) in number of remains (NR), minimum number of individuals (MNI), percentage (%), and distribution of each taxon in the habitats where they
Figure 3Amphibians from the late middle Pleistocene of Estanque de Tormentas de Butarque H-02 (central Spain).
Pelodytidae: cf. Pelodytes sp
Bufonidae: Bufo calamita
Ranidae: Pelophylax perezi
SQUAMATE REPTILES FROM ETB (H-02)
Lacertidae: Lacertidae indet
Colubridae: Natrix natrix
Colubridae: Coronella girondica
SOME CONSIDERATIONS ON THE H-02 (ETB) HERPETOFAUNAL ASSEMBLAGE
Figure 4Squamate reptiles from the late middle Pleistocene of Estanque de Tormentas de Butarque H-02 (central Spain).
PALEOENVIRONMENTAL AND PALEOCLIMATIC RECONSTRUCTIONS
Climate interpreted from fossil amphibians and reptiles
Table 2Climatic parameters calculated (in °C for temperature and mm for precipitation) by the mutual ecogeographic range method for Estanque de Tormentas de Butarque (H-02) and comparison with the climatic values (1970–2001) from the weather stat
Figure 5(color online) Paleoclimatic reconstruction of Estanque de Tormentas de Butarque (ETB) H-02 according to the mutual ecogeographic range method and comparison with modern data from the weather station 3182E of Arganda ‘Comunidad’ (Ni
Table 3Climatic interpretation of the climatograms.
Local environment interpreted on the basis of the fossil amphibians and reptiles
DISCUSSION AND COMPARISONS
Comparison with other H-02 (ETB) proxies
Figure 6(color online) Paleoenvironmental reconstruction of Estanque de Tormentas de Butarque H-02 according to the habitat weighting method, with (A) and without (B) water-edge taxa (Discoglossus, Pelophylax perezi, and Emys/Mauremys).
Comparison with other MIS 6 records
CONCLUSIONS
Acknowledgments
ACKNOWLEDGEMENTS
References

Documents

A new middle Pleistocene (Marine Oxygen Isotope Stage 6