Paleobiogeographic and ecological context of early human dispersals in western Eurasia

International audienceEarly human dispersals from Africa are often regarded in the context of ecological belonging of archaic Homo to the carnivore guild (as a scavenger) and its commensalistic relationship with saber-toothed cats Megantereon and Homotherium. The scavenging hypothesis meets several contradictions: the hominid eco-physiology is ill-adapted for the scavenger ecological niche because of limited sense of smell capacities that makes hominids poor competitors with carnivorans, and the specific physiology of thermoregulation (sweating) that exposes hominid presence to ambushing saber-toothed cats. Scavenger niche capacity depends of ecosystem productivity, which normally is declining from low to high latitudes and thus limits diversity and dispersal of scavengers in boreal latitudes. Therefore, new scavenging opportunities for hominids in higher latitudes of Eurasia sound doubtful. The earliest human fossil findings in Western Eurasia are located south of the Alpine-Himalayan Mountain Belt (AMB), which also acted as a biogeographic border during Pliocene and Pleistocene for several herbivorous and mostly omnivorous mammal systematic groups and species (Theropithecus, Mitilanotherium, Cervus nestii, Ursus thibetanus, etc.). In this case, Homo ex gr. erectus differs from ubiquitous carnivorans. The sharp annual seasonality that characterized Early Pleistocene climate of Western Eurasia in the north of AMB could be a limiting factor for human dispersal. Paradoxically, hominine dispersal advanced to the north in Western Europe after climate deterioration ca. 1.0 Ma. The use of fire could be among the factors that permitted to overcome AMB. The Movius Line, which demonstrates a technological difference between the early prehistoric tool technologies in East and West of the Old World and generally coincides with AMB with exception of its western part, is an indirect evidence of the early Middle Pleistocene hominine dispersal in Western Eurasia. The area of human distribution in Western Europe during early Middle Pleistocene also acted as natural zoogeographic refugia for some Villafranchian holdovers, mostly cervids

Deer from Late Miocene to Pleistocene of Western Palearctic: matching fossil record and molecular phylogeny data

This article proposes a brief overview of opinions on cervid systematics and phylogeny, as well as some unresolved taxonomical issues, morphology and systematics of the most important or little known mainland cervid genera and species from Late Miocene and Plio-Pleistocene of Western Eurasia and from Late Pleistocene and Holocene of North Africa. The Late Miocene genera Cervavitus and Pliocervus from Western Eurasia are included in the subfamily Capreolinae. A cervid close to Cervavitus could be a direct forerunner of the modern genus Alces. The matching of results of molecular phylogeny and data from cervid paleontological record revealed the paleozoogeographical context of origin of modern cervid subfamilies. Subfamilies Capreolinae and Cervinae are regarded as two Late Miocene adaptive radiations within the Palearctic zoogeographic province and Eastern part of Oriental province respectively. The modern clade of Eurasian Capreolinae is significantly depleted due to climate shifts that repeatedly changed climate-geographic conditions of Northern Eurasia. The clade of Cervinae that evolved in stable subtropical conditions gave several later radiations (including the latest one with Cervus, Rusa, Panolia, and Hyelaphus) and remains generally intact until present days. During Plio-Pleistocene, cervines repeatedly dispersed in Palearctic part of Eurasia, however many of those lineages have become extinct

EOSTYLOCEROS CF. PIDOPLITSCHKOI KOROTKEVITSCH 1964 (CERVIDAE, MUNTIACINAE): NEW ELEMENT IN THE NEOGENE MAMMAL ASSEMBLAGE OF LOWER VALDARNO (TUSCANY, CENTRAL ITALY)

An Eostyloceros antler fragment is described. The specimen makes part of the Montopoli (Lower Valdarno, Tuscany) collection preserved in the Geo-Paleontological section of the Natural History Museum of Florence. This site is the type locality of the homonymous Faunal Unit of the Italian Biochronological scheme; it includes the latest Early Villafranchian Mammal Age faunas. The occurrence of an Eostyloceros species among this material however, is in disagreement with the age of the Montopoli local fauna, which has been correlated with the Gauss-Matuyama boundary and thus dated to about 2.6 Ma. The youngest remains of this genus come from sites of eastern Europe Early Pliocene in age (Ruscinian Mammal Age). The possibility that the antler is an external element to the Montopoli assemblage is therefore contemplated.

Deer from Late Miocene to Pleistocene of Western Palearctic: matching fossil record and molecular phylogeny data

This article proposes a brief overview of opinions on cervid systematics and phylogeny, as well as some unresolved taxonomical issues, morphology and systematics of the most important or little known mainland cervid genera and species from Late Miocene and Plio-Pleistocene of Western Eurasia and from Late Pleistocene and Holocene of North Africa. The Late Miocene genera Cervavitus and Pliocervus from Western Eurasia are included in the subfamily Capreolinae. A cervid close to Cervavitus could be a direct forerunner of the modern genus Alces. The matching of results of molecular phylogeny and data from cervid paleontological record revealed the paleozoogeographical context of origin of modern cervid subfamilies. Subfamilies Capreolinae and Cervinae are regarded as two Late Miocene adaptive radiations within the Palearctic zoogeographic province and Eastern part of Oriental province respectively. The modern clade of Eurasian Capreolinae is significantly depleted due to climate shifts that repeatedly changed climate-geographic conditions of Northern Eurasia. The clade of Cervinae that evolved in stable subtropical conditions gave several later radiations (including the latest one with Cervus, Rusa, Panolia, and Hyelaphus) and remains generally intact until present days. During Plio-Pleistocene, cervines repeatedly dispersed in Palearctic part of Eurasia, however many of those lineages have become extinct

Ecological limiting factors of early hominins in western Eurasia

Introduction. Early hominin (Homo ex. gr. erectus) dispersals from Africa into western Eurasia took place during the Early Pleistocene. Evidence points to the presence of humans in Western Europe, specifically Spain, around 1.1-1.2 Ma and in the Transcaucasian region (Dmanisi) at approximately 1.8 Ma. Hominin re-mains in western Eurasia are predominantly found south of the Alpine Mountain Belt (AMB). The initial dispersal of Homofrom Africa is linked to their ecological relationship with Early Pleistocene predators. However, scavenging alone doesn't fully account for the restricted distribution of Homo in comparison to carnivores. A climate shift around 1.0 Ma led to the extinction of warm-loving species, including carnivores, and simultaneously expanded the geographical range of archaic humans. Aim. This study aims to identify ecological factors that influenced the distribution of archaic hominins in western Eurasia during the Early and Middle Pleistocene. Material and methods. The research employed multivariate cluster analysis on regional faunal lists in western Eurasia, with a specific focus on hoofed mammals and primates. Cluster analysis was conducted using the Jaccard Similarity Index, which is designed for presence-absence data. Results. Cluster analysis has revealed the Alpine Mountain Belt (AMB) to function as a zoogeographic boundary during the Early Pleistocene. It served as a protective barrier, safeguarding southern regions from climate deterioration. Notably, early hominins in Dmanisi might represent a relict population that endured in the Transcaucasian refugium following the decline of the Afrotropical zoogeographic realm, as exemplified by the fauna in Bethlehem. This suggests that the hominins of Dmanisi represent an isolated refugial population that persisted after the retreat of the Afrotropical realm to the south. Early hominin dispersals to Iberia are believed to have occurred through the Balkans and Western Europe. This movement was likely facilitated by a warm climate and the influence of the Gulf Stream. The emergence of the Movius Line (ML) during the Middle Pleistocene marks a new biogeographic boundary, indicating an increased density of hominin populations (Homo cf. heidelbergensis) in Western Europe during the Early and Middle Pleistocene. This biogeographic division aligns with the results obtained from faunal cluster analysis. The heightened population density in Western Europe could be attributed to its mild climate under the influence of the Gulf Stream, often referred to as a "wet climate refugium." Conversely, the sharp seasonality and continental climate north of the mountain belt in western Eurasia during the Early Pleistocene may have restricted early human dispersals. Notably, the seasonal drop in temperature below freezing point could have posed a significant limitation. The utilization of fire played a pivotal role in enabling hominins to move north of the AMB and adapt to lower temperatures. Conclusions. The AMB functioned as a crucial ecological boundary during the early Homo dispersal, creating favorable conditions in southern Western Eurasia. Notably, seasonal temperature drops were the primary limiting factors for hominin dispersal in Western Europe during the Early Pleistocene. By around 1.0 Ma, Western Europe had transformed into a “wet climate refugia” for certain species. The strong continental climate to the east of the Movius Line (ML) posed a significant limitation for human dispersal

The research of biocompatibility and functional properties of implants from modern materials made from titanium alloys

Catedra Traumatologie, ortopedie şi chirurgia de campanie, Catedra de anatomie topografică şi chirurgie operatorie USMF „Nicolae Testemiţanu”Our study established the biocompatibility of the nitinol implants in the embryonic cultures, for the first time. On the basis of the positive result obtained, the morphological changes in living tissues and bones at their contact region with the implants have been determined. Thus any presence of citotoxicity and of the negative effect upon reparatory osteogenesys was not detected. Our next step was to determine the anthropometric and physicomechanical properties of the coraco-clavicular ligaments in fresh cadavers. Finally, we suggested a brand new nitinol implant having similar to coraco-clavicular ligaments properties. Our innovation has been patented. În acest studiu pentru prima dată a fost determinată biocompatibilitatea implantelor de nitinol cu ajutorul culturilor celulare embrionare. Obţinînd un rezultat pozitiv, s-a efectuat cercetarea schimbărilor morfologice în regiunea de contact a implanturilor cu ţesuturile moi şi osul in vivo. Astfel, s-a demonstrat lipsa citotoxicităţii acestora şi a efectului negativ asupra osteogenezei reparatorii. Apoi a urmat aprecierea pe cadavre a caracteristicilor antropometrice şi fizico-mecanice a ligamentelor coraco-claviculare. În final am propus un fixator inovator din nitinol, cu capacităţi fizico-mecanice analogice ligamentelor coraco-claviculare, care a fost brevetat

Special features in pelvic injury treatment with hemodynamic instability

Catedra Ortopedie, Traumatologie şi Chirurgie în campanie, Catedra Chirurgie N1 ”N. Anestiadi”, USMF „Nicolae Testemiţanu”, Conferinţa a XI-a Naţională a ortopezilor-tramatologi din Republica Moldova “Politraumatisme – concepţii contemporane de diagnostic şi tratament”, 21 mai 2009, Chișinău, Republica MoldovaAutorii pun în discuție cele mai recente concepte referitor la „traumatismul complex pelvin”, asociat cu hemoragii masive și un risc înalt de letalitate. Este prezentat protocolul diagnostico-curativ de urgenţă specific în tratamentul acestor leziuni.Authors have performed an analise of the most recent concepts about „complex pelvic injury”, which is combined with massive haemorrhage and high level of lethality. There are presented an special protocol for a treatment of this gravely pathology

LAS AUTORIDADES SALEN DE MISA [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201