Francesc Burjachs

The first hominin of Europe

The earliest hominin occupation of Europe is one of the most debated topics in palaeoanthropology. However, the purportedly oldest of the Early Pleistocene sites in Eurasia lack precise age control and contain stone tools rather than human fossil remains. Here we report the discovery of a human mandible associated with an assemblage of Mode 1 lithic tools and faunal remains bearing traces of hominin processing, in stratigraphic level TE9 at the site of the Sima del Elefante, Atapuerca, Spain. Level TE9 has been dated to the Early Pleistocene (approximately 1.2–1.1u2009Myr), based on a combination of palaeomagnetism, cosmogenic nuclides and biostratigraphy. The Sima del Elefante site thus emerges as the oldest, most accurately dated record of human occupation in Europe, to our knowledge. The study of the human mandible suggests that the first settlement of Western Europe could be related to an early demographic expansion out of Africa. The new evidence, with previous findings in other Atapuerca sites (level TD6 from Gran Dolina), also suggests that a speciation event occurred in this extreme area of the Eurasian continent during the Early Pleistocene, initiating the hominin lineage represented by the TE9 and TD6 hominins.

The palaeoecoloical potential of pollen records in caves: the case of Mediterranean Spain

Abstract Important palynological sequences are reviewed from caves with archaeological interest in Mediterranean Spain. Upper Pleistocene sites include Abric Romani and Abric de l’Arbreda in NE Spain, and in SE Spain Cueva de la Carihuela, Cova Beneito, Cueva de Perneras, Cueva del Algarrobo and the Holocene Cova de l’Or and Cova de les Cendres. Carihuela has the longest sequence, starting in the last interglacial and covering most of the last glaciation. A pre-Wurm phase was followed by two glacial maxima separated by an interpleniglacial phase, and in the Lateglacial the Younger Dryas seems present. Whereas at Carihuela harsh pleniglacial conditions caused Mediterranean associations to disappear, in the milder surroundings of Beneito and Perneras these were able to survive. At Romani, pollen shows acute palaeoclimatic sensitivity, pointing to upland refuges nearby. Holocene pollen from Cova de l’Or and Cendres underlines the importance of pine in natural woodlands of mature meso and thermomediterranean taxa. Some between-site comparisons and contrasts with modern bioclimatology are interpreted in the context of the palaeoclimate history. Despite taphonomical and methodological problems of cave palynology, its future in arid regions such as SE Spain is promising.

A new Lower Pleistocene archeological site in Europe (Vallparadís, Barcelona, Spain)

Here we report the discovery of a new late Lower Pleistocene site named Vallparadís (Barcelona, Spain) that produced a rich archeological and paleontological sequence dated from the upper boundary of the Jaramillo subchron to the early Middle Pleistocene. This deposit contained a main archeological layer with numerous artifacts and a rich macromammalian assemblage, some of which bore cut marks, that could indicate that hominins had access to carcasses. Paleomagnetic analysis, electron spin resonance-uranium series (ESR-US), and the biostratigraphic chronological position of the macro- and micromammal and lithic assemblages of this layer reinforce the proposal that hominins inhabited Europe during the Lower Pleistocene. The archeological sequence provides key information on the successful adaptation of European hominins that preceded the well-known fossil population from Atapuerca and succeeded the finds from Orce basin. Hence, this discovery enables us to close a major chronological gap in the early prehistory of Iberia. According to the information in this paper and the available data from these other sites, we propose that Mediterranean Western Europe was repeatedly and perhaps continuously occupied during the late Matuyama chron.

Age and Date for Early Arrival of the Acheulian in Europe (Barranc de la Boella, la Canonja, Spain)

The first arrivals of hominin populations into Eurasia during the Early Pleistocene are currently considered to have occurred as short and poorly dated biological dispersions. Questions as to the tempo and mode of these early prehistoric settlements have given rise to debates concerning the taxonomic significance of the lithic assemblages, as trace fossils, and the geographical distribution of the technological traditions found in the Lower Palaeolithic record. Here, we report on the Barranc de la Boella site which has yielded a lithic assemblage dating to ∼1 million years ago that includes large cutting tools (LCT). We argue that distinct technological traditions coexisted in the Iberian archaeological repertoires of the late Early Pleistocene age in a similar way to the earliest sub-Saharan African artefact assemblages. These differences between stone tool assemblages may be attributed to the different chronologies of hominin dispersal events. The archaeological record of Barranc de la Boella completes the geographical distribution of LCT assemblages across southern Eurasia during the EMPT (Early-Middle Pleistocene Transition, circa 942 to 641 kyr). Up to now, chronology of the earliest European LCT assemblages is based on the abundant Palaeolithic record found in terrace river sequences which have been dated to the end of the EMPT and later. However, the findings at Barranc de la Boella suggest that early LCT lithic assemblages appeared in the SW of Europe during earlier hominin dispersal episodes before the definitive colonization of temperate Eurasia took place.

A new key locality for the Pliocene vertebrate record of Europe: the Camp dels Ninots maar (NE Spain)

A new Pliocene Konservat-Lagerstatte in north-eastern Spain is described here for the first time. It is referred to as Camp dels Ninots. The particular geological conditions of the site, which correspond to lacustrine sedimentation in a maar, made it ideal for the preservation of fossils. At present, five large mammal skeletons in anatomical connection have been recovered: three individuals of Alephis tigneresi, one of Stephanorhinus jeanvireti and one of Tapirus arvernenis, as well as isolated remains. A minimum of five individuals of the chelonian Mauremys leprosa have been recovered, some of them in anatomical connection. The rodent Apodemus atavus, the amphibians cf. Pleurodeles sp., Lissotriton aff. helveticus and Pelophylax cf. perezi and freshwater fishes (Leuciscus ?) complete the vertebrate assemblage uncovered up to the present time. The coexistence of Stephanorhinus jeanvireti and Alephis tigneresi suggests an age of about 3.2Ma for the Camp dels Ninots, near the MN15-MN16 transition. The Camp del Ninots fossil record enables one to extend the biogeographic range of some vertebrate taxa, such as Stephanorhinus jeanvireti, Tapirus arvernensis or Mauremys leprosa to the Iberian Peninsula. Taphonomic evidences of the skeletal remains indicates minimal (if any) weathering. Deposition at the lake bottom seems to have taken place in oxygen depleted layers. In this way, Camp dels Ninots is comparable to other remarkable maar sites such as Messel, the Eocene site situated in Germany.

Recent gully erosion in the El Cautivo badlands (Tabernas, SE Spain).

Abstract Detailed geomorphic observations in El Cautivo badland area, in the semiarid SE of Spain, show a recent renewal of linear channel erosion following a period of aggradation. Prior to this renewal, the landscape was characterized by smooth colluvial pediments on the north-east facing aspects and relatively steep crusted microhillslopes on south-west facing aspects. First-order valleys within the badland landscape were smooth-floored and filled with silty deposits connected with pediment colluvial deposits. The conditions under which valley bottom deposition was replaced by channel incision were analyzed by a study of flow hydraulics (magnitude–frequency of eroding events vs. resistance of valley floor to water flow) and the pollen sequence in the recently cut deposits. Changes in the vegetation-carpeting the valley bottom seem to be responsible for the deposition–erosion alternation rather than changes in the magnitude–frequency of major runoff events, given the high sensitivity of flow hydraulics to changes in roughness. Present rainfall rates would not, on their own, be able to erode a well-vegetated valley bottom. Yet, the pollen sequence in the valley fills demonstrates a progressive deterioration in climatic conditions with the eventual disappearance of groups that require a constant level of soil moisture (Alnus, Corylus, Cyperaceae). An increase in yearly rainfall or a change in temporal patterns would increase infiltration leading to permanent denser vegetation on footslopes and valley floors, helped by the natural water harvesting system. This vegetation cover would reduce the flow velocity and induce the deposition of the colluvium and valley fills, whereas erosion on headslopes would have been active enough to supply the sediments that were deposited downslope or on the valley bottoms. The reactivation of linear erosion would seem, therefore, to be a consequence of the decay of this permanent vegetation, induced by an increase in the duration or severity of drought periods, which meant that the water storage capacity of the valley fillings was insufficient to support it.

Meromixis origin and recent trophic evolution in the Spanish mountain lake La Cruz

Abstract: A sediment core from a Mediterranean karstic lake was studied through its pollen, diatom, chydorid, ostracod, charcoal and authigenic mineral composition. Information about environmental history recorded in the sediment sequence since the Middle Ages is presented. The main fluctuations of water volume and trophic status of the lake occurred during periods of great change in land management and during climatic cold phases. The synergetic effect of these two factors led to a high water level phase and triggered a rising of the trophic level which produced meromixis. The onset of meromictic conditions at about 1700 AD coincides with the Maunder minimum in the Little Ice Age as well as with a period of increasing human population, woodland clearance and agricultural expansion to the detriment of the nomadic livestock breeding or transhumance (Mesta).

Late Glacial to Early Holocene environmental adjustment in the Mediterranean semi-arid zone of the Salines playa-lake (Alacant, Spain)

The transition from the Late Glacial to the Early Holocene in the endorheic Salines sequence, which is characterized cyclical sedimentation, occurs between 5.50 and 2.85 m depth. From 5.50-3.50 m depth the cycles are composed of a centimetre alternation of layers of dolomitic marls and gypsarenites and from 3.50-2.85 m depth by the alternation of calcitic marls and calcarenites.Pollen, biotic assemblages and geochemistry provide evidence of a gap with respect to the new hydrological conditions that characterized the beginning of the Holocene. Mesic pollen taxa increased their percentages at the beginning of the Holocene, indicating climate improvement, which coincides with the 14C radiocarbon age of 10,000 years BP. The first biotic remains (gastropods, ostracods and foraminifers) found in this sequence appeared later, at 3.80 m depth, which corresponds to 9,500 years BP, whereas the mineralogical change occurred at 3.50 m depth, which corresponds to 9,000 years BP. The advanced adaptation of the vegetation and biotic aquatic assemblages with respect to the mineralogical response corresponds to a process of a gradual increase in water availability into the lacustrine system. During the Boreal, the calcitic cycles reached their maximum thickness, suggesting a more continuous water input. This assumption has also been corroborated by the expansion of the mesic pollen taxa and the occurrence of biota taxa which depend on a permanent water body for their development.The multiproxy approach in paleoclimate scenarios is an essential tool for understanding the ecosystem adjustment during climate changes. Our results demonstrate an interval of 1000 years between the vegetal and the mineralogical reaction.

High-resolution saline lake sediments as enhanced tools for relating proxy paleolake records to recent climatic data series

Abstract Lake level in an endorheic saline lake in Southern Europe has been inferred for the last 105 years (1889–1994) at an annual level of resolution using two independent methods. First, ordination analyses (factor analysis (FA), correspondence analysis (CA) and detrended correspondence analysis (DCA)) have been used to point out the mineral successions of the sedimentary record. These successions are evidenced by the arch disposition of both samples and mineral phases in the plane defined by the first two eigenvectors calculated by these analyses. These temporal evolutions are the same as those obtained during the drying and refilling phases of saline lakes. Relay indices (RI) were obtained from distances to the first two eigenvectors, which accurately reconstructed the lake-level evolution during this period. Second, an inferred lake-level series was obtained using a multivariate time series model from the average maximum temperatures and total rainfall. Six main drought periods were found, which coincided with known droughts in the area. A high level of agreement was found between the two reconstructions, which offered the possibility of directly extending the instrumental record back into the past. Therefore, climatic changes could be reconstructed from saline lakes provided that an accurate chronological control of sedimentary processes is available.

Eurasian Gates: The Earliest Human Dispersals

This paper revises the current state of the debate about the earliest hominin dispersals out of Africa. First we review the archaeological evidence for the earliest occupation of Asia and Europe. Next we summarize the environmental parameters related to the earliest phases of human evolution--specifically, climatic implications for human adaptations andfaunal dispersals. We discuss which were the first hominins to leave Africa, and we propose the invention of technology as a fundamental step for the development of our genus, likely related to changes in subsistence and diet during the late Pliocene and early Pleistocene. From our point of view, hominins were able to generalize the use of technology, as well as to generate, integrate, and diffuse new information into their collective social behavior. We refer to this concept as socialization. Hence, technology and the socialization thereof became integral aspects of the ecological niche of hominins.