Antonio Guerreschi

Sedimentary and pedological processes in the Upper Pleistocene loess of northern Italy. The Bagaggera sequence

Abstract The Bagaggera sequence consists of two Late Pleistocene loesses superimposed on the top of Middle Pleistocene fluviatile sediments. The lower loess includes at its base a Mousterian archaeological level represented by artifacts (dated by TL as 60,500 ± 7500 BP) and charcoal from hearths which mainly consists of boreal forest species. At the top of the lower loess, Aurignacian artifacts occur which suggest a tentative date of 35,000 BP. The sedimentary and pedological processes which lead to the formation of the sequence, were reconstructed by means of mineral and textural analyses and thin section analysis and can be summarized as follows: - Erosion and colluviation of the Eemian soil at the base of the sequence during the Early Wurm (Isotopic Substages 5 a-c). - Sedimentation of the lower loess deposits during the first Pleniglacial period (Isotopic Stage 4). A large number of coarse pedofeatures in this soil suggests that primary aeolian dust has been redistributed in place or for short distances by syngenetic slight pedogenesis and by water reworking, as a result of alternating phases of wet and dry climate. - An alfisol characterized by strong clay illuviation developed in the lower loess during the Hengelo-Arcy interstadial phase. Its top was affected by reworking and slight frost activity at the beginning of the second Pleniglacial period (Isotopic Stage 2). - The upper loess was deposited in a drier environment during the second Pleniglacial period (Isotopic Stage 2). Water reworking was less effective. - Holocene weathering is expressed by clay illuviation and slight hydromorphism.

Early cave art and ancient DNA record the origin of European bison

The two living species of bison (European and American) are among the few terrestrial megafauna to have survived the late Pleistocene extinctions. Despite the extensive bovid fossil record in Eurasia, the evolutionary history of the European bison (or wisent, Bison bonasus) before the Holocene (<11.7 thousand years ago (kya)) remains a mystery. We use complete ancient mitochondrial genomes and genome-wide nuclear DNA surveys to reveal that the wisent is the product of hybridization between the extinct steppe bison (Bison priscus) and ancestors of modern cattle (aurochs, Bos primigenius) before 120 kya, and contains up to 10% aurochs genomic ancestry. Although undetected within the fossil record, ancestors of the wisent have alternated ecological dominance with steppe bison in association with major environmental shifts since at least 55 kya. Early cave artists recorded distinct morphological forms consistent with these replacement events, around the Last Glacial Maximum (LGM, ∼21–18 kya).

Late Upper Palaeolithic human diet: first stable isotope evidence from Riparo Tagliente (Verona, Italy)

This article reports results of carbon (13C/12C) and nitrogen (15N/14N) stable isotope analysis performed on the bone collagen of a Late Epigravettian human individual and 11 faunal remains from the Upper Palaeolithic deposits of Riparo Tagliente (Verona, Italy). Riparo Tagliente is located in Valpantena on the pre-alpine massif of Monti Lessini, at 250 m a.s.l. Its strategic position, about halfway from the plain and the top of the limestone plateau, has allowed the groups that occupied the site to exploit different ecosystems. The human skeleton comes from an incomplete burial excavated in 1973 and belongs to a young adult male. It is dated between 16,634 and 15,286 cal BP (OxA-10672). The δ13C (−18.4‰) and δ15N (13.0‰) values of the human individual are enriched compared to those of herbivores on average by +1.2‰ in 13C and +10.0‰ in 15N, and to the omnivores on average by +1.4‰ in 13C and +7.2‰ in 15N. Isotopic values would indicate an origin of proteins from terrestrial herbivores and high trophic level species. These data match with the results of taphonomic analyses carried out on the bone remains of herbivores, while the study of other species as fish is still in progress.RésuméDans l’objectif d’étudier les modes de subsistance à l’Épigravettien récent, des analyses isotopiques (carbone et azote) ont été réalisées sur le collagène osseux d’un sujet humain et de plusieurs espèces animales de la série Paléolithique supérieur de Riparo Tagliente (Vérone, Italie). Le site est localisé dans le fond de vallée du Valpantena, sur le massif préalpin des Monts Lessini, à 250 m au-dessus du niveau marin. Ce site occupe une position qui favorise l’accès a différents écosystèmes, environ à mi-chemin entre la plaine et le sommet du plateau calcaire. Les restes humains sont ceux d’un jeune adulte de sexe masculin, datés entre 16634-15286 cal BP. Les valeurs isotopiques du sujet humain (δ13C : −18,4 ‰ ; δ15N : 13,0 ‰) montrent un enrichissement important comparativement à la faune herbivore (+1,2 ‰ en 13C et +10,0‰ en 15N) et par rapport à la faune omnivore du même site (+1,4‰ en 13C et +7,2 ‰ en 15N). Les valeurs isotopiques (δ13C, δ15N) enregistrées sur le sujet indiquent que les protéines consommees ont plusieurs origines impliquant des espèces de niveaux trophiques différents. L’etude des traces de boucherie sur la faune herbivore terrestre confirme une partie de ces résultats. Malgré la présence de poisson sur le site, aucune information n’est disponible à ce jour pour discuter des espèces concernées et de leur rôle dans l’alimentation humaine.