In the Footprints of Our Ancestors: An Overview of the Hominid Track Record

Hominid footprints are particularly appealing and evocative of the living activity of our ancestors. The most famous and oldest (Late Pliocene, ca. 3.7 Ma) hominid footprints, from Laetoli in East Africa, have been attributed, with some uncertainly, to genus Homo or Australopithecus. The African track record also yields Early Pleistocene (～1.5 Ma) tracks attributable to Homo erectus. The only well-documented Middle Pleistocene tracks (age ～325,000-385,000 yrs) are reported from Italy and presumably represent a pre-Homo sapiens species.

The oldest Late Pleistocene tracks (～117,000 yrs), from southern Africa, may represent modern humans. However, the majority of Late Pleistocene sites are European, associated with caves in Romania, Greece, France and elsewhere, where hominid track preservation is often of high quality. Dates range from ～10,000 to ～62,000 BP Cavesite mammal tracks are almost exclusively those of carnivores, thus representing a distinctive underground ecology. Late Pleistocene open air sites are reported from widely scattered locations in Africa, Turkey, Tibet, Korea, Australia and even in the New World (Chile, Argentina and Mexico).

Early to Middle Holocene sites (> ～4,000 yrs BP) mainly occupy riparian, lacustrine, estuarine and littoral settings where the ichnofaunas are dominated by ungulates and shorebirds. Among these sites from England, Nicaragua, Argentina and Mexico and the United States, a few have been described in some detail. Younger Holocene sites are frequently associated with specified cultural periods (e.g., Neolithic, Bronze Age) or specific indigenous cultures, where supplemental archeological evidence may be directly associated with the footprint evidence.

At most surficial and some subterranean hominid tracksites, mammal and/or bird tracks are quite common and of use in creating a paleoecological picture of local faunas. The global distribution of human and hominid tracks is consistent with body fossil evidence and the record of archeological, cultural artifacts. However, in a few cases tracks suggest colonization of certain regions (Tibetan Plateau and the New World) earlier than previously thought. Tracks also give clues to behavior, age and health status of the trackmakers.     

A Brief Sketch of the Monte Hermoso Human Footprint Site,South Coast of Buenos Aires Province,Argentina

Tracksites representing early human occupation are rare in South America. However, they have been reported in association with mammal and bird tracks from two coastal sites in Buenos Aires Province, Argentina. Both sites are reported in separate papers in this volume. In this paper a brief summary of the better known site is given on the basis of published information and the author's observations.     

Genetic diversity among isolates of Trichinella spiralis from the Province of Buenos Aires, Argentina

Random Amplified Polymorphic DNAs, (RAPDs) are used to study the occurrence of Trichinella britovi and T5 among domestic animals in the Province of Buenos Aires, Argentina and to assess the genetic diversity among isolates of T. spiralisfrom this area in a number of infected hosts. All the local isolates proved to be T. spiralis. Six of the eight primers used indicate that the Buenos Aires isolates are distinct from each other as they produce a considerable number of polymorphic bands. Our overall estimates are relatively higher than other intraspecific distances previously estimated within species of this genus and among T. spiralis isolates. Such high degrees of variability observed among local isolates and between isolates from Buenos Aires and Spain should be taken into account when defining isolates within this species, and considering differences in the epidemiology of T. spiralis.     

Causes of Ecosystem Transformation at the End of the Pleistocene: Evidence from Mammal Body-Mass Distributions

Animal body sizes reflect the discontinuous architecture of the landscapes in which they live, and consequently their body-mass distributions are distinctly clumped rather than continuous. This architectural discontinuity is generated by ecological processes that discretely operate over micro-, meso-, and macroscales. Therefore, changes in these important scale-specific processes for a given geographical region over time should be reflected by corresponding changes in faunal body-mass clump patterns. In this study, we utilized this hypothesis to investigate the terminal Pleistocene mammal extinction event. Specifically, we analyzed the body-mass distributions of latest Pleistocene and modern mammal faunas from northern Florida and southern California to determine the nature of any changes in the clump structures of these regions during the Pleistocene–Holocene transition. In both regions, despite their wide geographical separation and faunal distinctiveness, body-mass clumps below the 40-kg level were remarkably stable across the Pleistocene–Holocene transition despite suffering extinctions. Larger clumps, in contrast, were either orderly truncated or completely eliminated rather than chaotically fragmented. Based on these findings, we argue that the terminal Pleistocene mammal extinctions were caused, at least in part, by changes in key mesoscale aspects of the landscape crucial to supporting a diversity of large mammals. Received 23 April 1997; accepted 14 October 1997.     

Stable isotope composition of Littoridina australis from the coast of Buenos Aires province, Argentina, during Holocene climatic fluctuations

Stable isotope (carbon and oxygen) analyses were performed on Littoridina australis shells collected from molluscan concentrations within Holocene littoral deposits along the Bonaerensian coastal area of Argentina (south-western Atlantic). Isotope data allow us to define two very different areas: the Samborombon Bay, where isotope composition of shells was mainly governed by mixing between marine and freshwater, and the Mar Chiquita lagoon, where the original brackish environment was dominated by evaporation of water that originated high isotope shell values. In both areas some isotope profiles show short and quite large oscillations in δ¹⁸O. Their origin may be tentatively explained as due to the changes in moisture regime that control freshwater supply. The results suggest that these deposits can represent natural archives potentially useful for palaeoclimate reconstruction.     

Biostratigraphy and biochronology of the Late Miocene of central Argentina: Evidence from rodents and taphonomy

Biostratigraphy and biochronology of the Late Miocene of central Argentina is analyzed through evolutionary patterns of octodontoid rodents. The studied faunas were found in continental sediments assigned to the Cerro Azul and Saldungaray formations (La Pampa and Buenos Aires provinces, respectively). Taphonomic attributes of recovered mammals, linked mostly to the development of paleosols or to predators’ activities, constraint the deposition lapse to short intervals. A biostratigraphic scheme based mainly on the anagenetic pattern of change in the octodontoid rodent lineage Chasichimys-Xenodontomys is proposed. Since there is no stratigraphic superposition among the studied levels, relationships among deposits are established through the polarity evidenced by the stage of evolution of chronomorphs of this lineage. Five new biozones for the Late Miocene of central Argentina are recognized. Evidence of other anagenetic sequences, and general trends of increasing hypsodonty in octodontoids, support this proposal. The results enhance the value of the “stage of evolution” concept as a correlation tool in biostratigraphic and biochronologic studies, mainly when applied through phyletic sequences.     

Review of dated Late Quaternary palaeolimnological records in the Carpathian Region,east-central Europe

The Carpathian Region (including mountains and plains) has for a long time been lacking good palaeoenvironmental and especially palaeolimnological records, particularly for the Late Quaternary. In the last two decades, many new sedimentary sequences were obtained and studied using a wide range of palaeoproxies. This article reviews results from 123 sequences in the Carpathian Region, all dated by radiometric methods. Our aim was to pay attention to the existence of these data; many of them published in national periodicals and journals. Palaeoenvironmental records with at least two proxies and with palaeolimnological interpretation were compiled in both tabular form and on maps. Inspite of the density of examined sites, an assessment of the dataset led us to the following conclusions: (1) very few provide firm hydrological–limnological interpretation, such as lake level and mire water-depth fluctuation, lake productivity changes and pH changes; (2) only 47 of them are real multi-proxy studies (have at least two proxies employed on the same sediment core); (3) glacial lakes in Slovakia and Romania as well as in Ukraine are seriously under-investigated although they would be ideal objects of palaeolimnological works with the many proxies applicable on them; (4) the Hungarian lowland areas are dominated by shallow tectonic lakes or palaeochannels, often with unsatisfactory preservation of certain biological proxies (e.g. diatoms, chironomids, cladocerans). Consequently, palaeolimnological studies from this region have to apply a different combination of proxies and approach than mountain lake studies.

Subsistence activities and the sexual division of labor in the European Upper Paleolithic and Mesolithic: Evidence from upper limb enthesopathies

Studies of cultural artifacts and faunal remains from European Upper Paleolithic and Mesolithic sites indicate a shift in hunter gatherer subsistence strategies, involving an intensification and diversification of resource exploitation relative to earlier foragers during the Tardiglacial and Postglacial periods. This trend has been recognized as well through the analysis of non-pathological skeletal adaptations of the upper limbs of European Upper Paleolithic human fossils. These paleoanthropological studies of adaptive bone modeling also raise the question of female use of throwing-based weapon technology in the Upper Paleolithic. Here, we studied another type of osteological marker of activity, enthesopathies, of the upper limb remains of 37 European Upper Paleolithic and Mesolithic human fossils, with the goal of testing two hypotheses: 1) that activity levels were heightened at the end of Upper Paleolithic and into the Mesolithic relative to earlier foragers of the Gravettian, and 2) that there was an absence of a marked sexual division of labor in European hunter-gatherers during this time span. Our results are consistent with the first hypothesis; upper limb enthesopathies are significantly less frequent in the Gravettian group, but raise doubts about the second hypothesis. Four males exhibit lesions that can be confidently associated with throwing activities, while no females exhibit such lesions.     

Coccolithophores in the equatorial Atlantic Ocean: response to seasonal and Late Quaternary surface water variability

The present study was initiated to ascertain the significance of coccolithophores as a proxy for paleoceanographic and paleoproductivity studies in the equatorial Atlantic. Data from a range of different samples, from the plankton, surface sediments as well as sediment cores are shown and compared with each other.In general, the living coccolithophores in the surface and subsurface waters show considerable variation in cell numbers and distribution patterns. Cell densities reached a maximum of up to 300×10³ coccospheres/l in the upwelling area of the equatorial Atlantic. Here, Emiliania huxleyi is the dominant species with relatively high cell numbers, whereas Umbellosphaera irregularis and Umbellosphaera tenuis are characteristic for oligotrophic surface waters. Although they are observed in high relative abundances, these species only occur in low absolute numbers. The lower photic zone is dominated by high abundances and considerable cell numbers of Florisphaera profunda.The geographical distribution pattern of coccoliths in surface sediments reflects the conditions of the overlying surface water masses. However, abundances of the oligotrophic species Umbellosphaera irregularis and Umbellosphaera tenuis are strongly diminished, causing an increase in relative abundance of the lower photic zone taxa Florisphaera profunda and Gladiolithus flabellatus.During the past 140,000 years the surface water circulation of the equatorial Atlantic has changed drastically, as can be seen from changes in the coccolithophore species composition, absolute coccolith numbers, as well as coccolith accumulation rates. Significant increases in coccolith numbers and accumulation rates is observed in the southern equatorial Atlantic during the last glacial interval (oxygen isotope stages 2–4), which we attribute to enhanced upwelling intensities and advection of cool nutrient rich waters at this site. In the western equatorial Atlantic we observe an opposite trend with decreasing numbers of coccoliths during glacial periods, which probably is caused by a deepening of the thermocline.     

Paleoreconstruction of Pleistocene environments of human habitats in the Late Pleistocene and Holocene near the Charyshskii Naves cave, Central Altai, Russia

The results of the study of the small mammal fauna from the Charyshskii Naves cave (Central Altai, Russia) in the 2003 field season are provided. The dynamics of fossil small mammals was studied and the natural habitats of the ancient man were reconstructed on this basis. Two stages of sedimentation, corresponding to the domination of different biotopes, were recognized.     

Late Quaternary paleoproductivity and deep water circulation in the eastern South Atlantic Ocean: Evidence from benthic foraminifera

Two late Quaternary sediment cores from the northern Cape Basin in the eastern South Atlantic Ocean were analyzed for their benthic foraminiferal content and benthic stable carbon isotope composition. The locations of the cores were selected such that both of them presently are bathed by North Atlantic Deep Water (NADW) and past changes in deep water circulation should be recorded simultaneously at both locations. However, the areas are different in terms of primary production. One core was recovered from the nutrient-depleted Walvis Ridge area, whereas the other one is from the continental slope just below the coastal upwelling mixing area where present day organic matter fluxes are shown to be moderately high. Recent data served as the basis for the interpretation of the late Quaternary faunal fluctuations and the paleoceanographic reconstruction.

During the last 450,000 years, NADW flux into the eastern South Atlantic Ocean has been restricted to interglacial periods, with the strongest dominance of a NADW-driven deep water circulation during interglacial stages 1, 9 and 11. At the continental margin, high productivity faunas and very low epibenthic δ¹³C values indicate enhanced fluxes of organic matter during glacial periods. This can be attributed to a glacial increase and lateral extension of coastal upwelling. The long term glacial-interglacial paleoproductivity cycles are superimposed by high-frequency variations with a period of about 23,000 yr. Enhanced productivity in surface waters above the Walvis Ridge, far from the coast, is indicated during glacial stages 8, 10 and 12. During these periods, cold, nutrient-rich filaments from the mixing area were probably driven as far as to the southeastern flank of the Walvis Ridge.     

A new species of Liniscus (Nematoda: Trichuridae) from Oxymycterus rufus and Akodon azarae (Cricetidae: Sigmodontinae) in Buenos Aires Province, Argentina

Liniscus diazae n. sp. (Nematoda: Trichuridae) is described from the urinary bladder of Oxymycterus rufus and Akodon azarae (Cricetidae: Sigmodontinae) from Buenos Aires Province, Argentina. Liniscus diazae can be differentiated from its congeners by having a much longer spicule and without an elevated vulva. In addition, L. diazae can be distinguished from L. incrassatus and L. himizu by having a longer body length. Males are similar in posterior width to L. papillosus and L. himizu, but thinner than L. incrassatus and L. maseri. This is the second record of a capillarid from mammals in Argentina. An updated list of capillarid species of rodents and insectivores from North America, with their synonyms, hosts, sites of infection, and geographic distribution, is provided.     

Seasonal fluctuation of the Oomycetes in a polluted environment: Santigo River and affluents (Buenos Aires, Argentina).

Oomycetes are ubiquitous filamentous water molds. They occur as saprotrophs on bits of substrata of both plant and animal origin, principally in fresh water. This paper results from an integral research on the Oomycetous flora of Santiago River and several associated shallow streams (Buenos Aires, Argentina). Information is provided concerning this polluted habitat and seasonal distribution of the zoosporic fungi. The principal physico-chemical characteristics of the aquatic environmental samples are described: temperature, pH, dissolved oxygen, nitrate concentration, sulphate concentration, phosphate concentration and heavy metals.     

Study of the Insects Associated with the Floodwater Mosquito Ochlerotatus Albifasciatus (Diptera: Culicidae) and their Possible Predators in Buenos Aires Province,Argentina

Insects associated with the floodwater mosquito Ochlerotatus albifasciatus(Diptera: Culicidae) were studied from intermittent puddles in temperate Argentina in an attempt to detect the main predators. Forty-one taxa occurred in the puddles from spring to fall. Coleoptera and Diptera were dominant and diverse. Ephemeroptera and Odonata were scarce in numbers and species, and Heteroptera occurred in low numbers of species and high abundance of individuals. The main predators of immature O. albifasciatus were detected on the basis of relative abundance (ISA index), ecological dominant groups, and species association (I index). Liodessus sp. and Rhantus signatus signatus(Coleoptera: Dytiscidae) were the most abundant predators in the puddles and Liodessus sp., Lancetes marginatus(Dytiscidae) and Psorophora ciliata(Culicidae) were the most frequent. Liodessus sp. and O. albifasciatus were the best associated species in all seasons. Liodessus sp. was indistinctly associated with all larval instars and pupae, while R. signatus signatus, L. marginatus and Psorophora ciliata were more associated with the pupal stage of the mosquito. Desmopachria concolor(Coleoptera: Dytiscidae), Tropisternus lateralis limbatus and Tropisternus setiger(Coleoptera: Hydrophilidae) were other potential predators inhabiting the puddles, but their relevance was minor.     

Fish assemblage of a Pampasic stream (Buenos Aires,Argentina): temporal variations and relationships with environmental variables

In the Argentine Pampa fertile soils were originally covered by grasslands, but at present are intensively cultivated. We assessed the specific composition of the fish assemblage of El Pescado stream and compared it with that recorded in 1991–1993, when land use in the watershed consisted in natural pastures. The persistence of the fish assemblage between the two studies was rather high: 0.76. Abundance, biomass and species richness were higher during drought periods. Connectivity with the huge Río de la Plata hydrographic system seems the most important contribution to the high and stable species richness of El Pescado stream.     

山顶洞人与现代华北人头骨非测量性特征比较及中国更新世晚期人类演化的一些问题

山顶洞人化石是迄今在东亚地区发现的数量最为丰富、保存状态最为完好的更新世晚期人类化石。多年来,山顶洞人作为东亚地区更新世晚期人类的代表,在研究东亚地区现代蒙古人种及美洲印第安人起源方面发挥着重要作用。随着对现代人起源与演化研究的深入,学术界对更新世晚期人类演化及现代人群形成过程的许多细节及演化机制予以了越来越多的注意,提出了现代人群出现时间及现代人群分化时间的概念。一些研究对山顶洞人的演化程度及其在东亚地区现代人群形成上的作用也提出了不同看法。为了深入探讨这些问题,本文对12项颅骨非测量特征在山顶洞人与现代中国人的表现情况进行了对比研究。发现有8项特征在山顶洞人与现代中国人之间具有不同的表现,作者认为山顶洞人在颅骨特征表现上较现代中国人具有更多的原始性。在此基础上,作者就更新世晚期人群内部变异、现代人群特征标准等问题进行了讨论。     

Soil contamination with Toxocara sp. eggs in squares and public places from the city of La Plata. Buenos Aires, Argentina

This study consisted of a stratified sampling, randomly taken, of the soil from the squares and parks of the city of La Plata, Province of Buenos Aires, in order to establish the prevalence of contamination caused by Toxocara sp. A total 242 soil samples was examined. From each sample a 10 grams aliquot was taken, washed in a 0.2% Tween 80 solution, and processed using the technique of concentration by flotation with sugar solution. There was a prevalence of 13.2%. In each positive sample, the quantity of eggs varied from 1 to 4. Toxocara sp. eggs were observed in 15 out of 22 squares and parks investigated. The sampling design and the processing method employed were satisfactory for the recovering and identification of Toxocara sp. eggs.     

Micromammals (rodents and insectivores) from the early Late Pleistocene cave site of Bois Roche (Charente, France): Systematics and paleoclimatology

We present the study of rodents and insectivores from the 1995 season of excavation at the early Late Pleistocene site of Bois Roche (Charente, France). The site is a small cave with a low ceiling, used as a den by hyenas. It contains a large herbivore assemblage (mainly bovids and equids) with a smaller representation of medium-size taxa (cervids), many microvertebrates, abundant coprolites and deciduous hyena teeth, and a few lithic artifacts (Middle Paleolithic) introduced into the cave by gravity and slope wash. The rodent fauna consists of Eliomys quercinus cf. quercinus, Apodemus sp., Microtus gregalis, Microtus oeconomus, Arvicola terrestris and Dicrostonyx torquatus. Insectivores are represented by Neomys cf. fodiens. The most common species is M. gregalis which forms 93.7% of the total MNI. The micromammal fauna suggests an open landscape, with some vegetation mainly of the steppe or tundra type, with areas of water and more wet vegetation and some areas with trees. The micromammal association of Bois Roche is characteristic of a cold or very cold dry climate.