Jonathan G Wynn

• PhD Geology
• Program Director at National Science Foundation

While our understanding of human origins has been enriched by extensive efforts to reconstruct the ancient environmental context of early hominins using information from hominin-bearing localities, comparatively little effort has been focused on contemporaneous fossil localities with abundant vertebrate fossils, but lacking hominins. We report here...

Cryogenic cave carbonates have been described from several formerly or presently glaciated karst caves. In most of these occurrences, they precipitated as loose grains or aggregates with various morphologies and sizes. Here, we report on a new speleothem type ( cryogenic ridges ) identified in Sohodoalele Mici Cave (SW Romania) within a large chamb...

Humans evolved in the dynamic landscapes of Africa under conditions of pronounced climatic, geological and environmental change during the past 7 million years. This book brings together detailed records of the paleontological and archaeological sites in Africa that provide the basic evidence for understanding the environments in which we evolved....

Humans evolved in the dynamic landscapes of Africa under conditions of pronounced climatic, geological and environmental change during the past 7 million years. This book brings together detailed records of the paleontological and archaeological sites in Africa that provide the basic evidence for understanding the environments in which we evolved....

Humans evolved in the dynamic landscapes of Africa under conditions of pronounced climatic, geological and environmental change during the past 7 million years. This book brings together detailed records of the paleontological and archaeological sites in Africa that provide the basic evidence for understanding the environments in which we evolved....

The isotopic composition of hydrogen in authigenic minerals is a useful tool to reconstruct past paleo-environments. Clay minerals are an important component of authigenic minerals in soils and sediments but they usually occur with other compounds that must be eliminated before the analysis, such as organic matter and carbonates. Thus, various "pre...

The bulk S elemental abundances and δ34S values for 83 carbonaceous chondrites (mostly CMs and CRs) and Semarkona (LL3.0) are reported. In addition, the S elemental abundances and δ34S values of insoluble organic material (IOM) isolated from 25 carbonaceous chondrites (CMs, CRs, and three ungrouped) are presented. The IOM only contributes 2–7% of t...

To explore the paleoenvironmental changes in SE Asia during the late Neogene, we examined the stable carbon and oxygen isotope compositions of tooth enamel from mammals of the late Pliocene/earliest Pleistocene Gwebin area in central Myanmar and compared the results with those of the latest Miocene Chaingzauk mammals in Myanmar. The stable carbon i...

Australopithecus anamensis, among the earliest fully bipedal hominin species, lived in eastern Africa around 4 Ma. Much of what is currently known about the paleoecology of A. anamensis comes from the type locality, Kanapoi, Kenya. Here, we extend knowledge of the range of environments occupied by A. anamensis by presenting the first multiproxy pal...

Stable hydrogen and oxygen isotope signatures of waters within Church and Inkwell blue holes are measured on San Salvador Island (Bahamas) to identify the origin of their fresh and saline waters. Stable isotope data, paired with a suite of physicochemical water parameters measured throughout the blue holes, as a function of both time and depth, pro...

The magnitude of the terrestrial carbon (C) sink may be overestimated globally due to the difficulty of accounting for all C losses across heterogeneous landscapes. More complete assessments of net landscape C balances (NLCB) are needed that integrate both emissions by fire and transfer to aquatic systems, two key loss pathways of terrestrial C. Th...

Significance Reconstructing the dietary adaptations of our earliest ancestors is critical to understanding the evolution of our relationship with our environment. Here, we present carbon isotope data from hominins of the Shungura and Usno Formations, both part of the Pliocene to Pleistocene Omo Group, Ethiopia, a key sequence for the study of homin...

Significance Studying the diet of fossil herbivores is a critical aspect of understanding past ecology. Here, we present carbon isotope data from the collective herbivore fauna in the Shungura Formation, Ethiopia, a key sequence for the study of mammalian evolution in eastern Africa. We document temporal patterns in the diet of nine mammalian herbi...

As tropical savannas are undergoing rapid conversion to other land uses, native C3‐C4 vegetation mixtures are often transformed to C3‐ or C4‐dominant systems, resulting in poorly understood changes to the soil carbon (C) cycle. Conventional models of the soil C cycle are based on assumptions that more labile components of the heterogenous soil orga...

Several hypotheses posit a link between the origin of Homo and climatic and environmental shifts between 3 and 2.5 Ma. Here we report on new results that shed light on the interplay between tectonics, basin migration and faunal change on the one hand and the fate of Australopithecus afarensis and the evolution of Homo on the other. Fieldwork at the...

The riverine export of carbon is expected to be driven by changes in connectivity between source areas and streams. Yet we lack a thorough understanding of the relative contributions of different water sources to the dissolved carbon flux, and of the way these contributions vary with seasonal changes in flow connectivity. Here we assess the tempora...

Millimeter-scale growth rings in canine dentine of MIS 3 cave bears have been interpreted as annual growth bands produced, in part, by seasonal variation in growth rate. We present new intra-tooth stable carbon (δ13C) and oxygen (δ18O) isotope profiles in dentine hydroxylapatite of early forming permanent teeth, from three famous Late Pleistocene c...

Despite recent evidence suggesting that groundwater inputs of dissolved inorganic carbon (DIC) to rivers can contribute substantially to the fluvial evasion of carbon dioxide (CO2), groundwater is seldom integrated into fluvial carbon budgets. Also, unclear is the way equilibria between CO2 and ionic forms of carbonate will affect CO2 evasion from...

First fossil sites from the Urema Rift, central Mozambique, and their paleoenvironmental and paleoecological contexts

The East African Rift System (EARS) has played a central role in our understanding of human origins and vertebrate evolution in the late Cenozoic of Africa. However, the distribution of fossil sites along the rift is highly biased towards its northern extent, and the types of paleoenvironments are primarily restricted to fluvial and lacustrine sett...

A 285‐cm core of bat guano was recovered from Măgurici Cave in north‐west Romania and analyzed for δ¹³C, δ¹⁵N and pollen. Guano deposition occurred from AD 881 until 1240 and from AD 1651 to 2013, allowing for the interpretation of summer variations in precipitation and temperature during the Medieval Warm Period (MWP) and the Little Ice Age (LIA)....

The western Mediterranean region is exceptionally vulnerable to predicted climate changes of increasing temperature and aridity. Characterizing past climate oscillations since the last interglacial (LIG) is critical to understand climate patterns during the present warm period. Here we present an accurately dated speleothem record (CAM-1) of paleoc...

Understanding the main factors driving fire regimes in grasslands and savannas is critical to better manage their biodiversity and functions. Moreover, improving our knowledge on pyrogenic carbon (PyC) dynamics, including formation, transport and deposition, is fundamental to better understand a significant slow-cycling component of the global carb...

δ13C and δ15N analysis was completed on a 285 cm guano deposit found in Măgurici Cave (NW Romania). A hiatus was found in the ~1.2 ka core between AD 1240 to AD 1651 that appears to correspond with the beginning of the Little Ice Age. δ13C values indicate that vegetation was exclusively C3 plants in the region since AD 800, therefore δ13C values of...

Among abundant reconstructions of Holocene climate in Europe, only a handful has addressed winter conditions, and most of these are restricted in length and/or resolution. Here we present a record of late autumn through early winter air temperature and moisture source changes in East-Central Europe for the Holocene, based on stable isotopic analysi...

Late Pleistocene European cave bears (Ursus spelaeus) have been considered to be largely vegetarian, although stable isotope data (δ13C and δ15N values) from the Romanian Carpathians has suggested considerable dietary variation. Here we evaluate previous and additional adult cave bear isotopic data from four Marine Isotope Stage 3 (MIS 3) sites in...

Late Pleistocene European cave bears (Ursus spelaeus) have been considered to be largely vegetarian, although stable isotope data (δ13C and δ15N values) from the Romanian Carpathians has suggested considerable dietary variation. Here we evaluate previous and additional adult cave bear isotopic data from four Marine Isotope Stage 3 (MIS 3) sites in...

Currently there is a scarcity of paleo-records related to the North Atlantic Oscillation (NAO), particularly in East-Central Europe (ECE). Here we report δ15N analysis of guano from a cave in NW Romania with the intent of reconstructing past variation in ECE hydroclimate and examine NAO impacts on winter precipitation. We argue that the δ15N values...

A major puzzle in human origins research is the question of where, when, and under what environmental conditions our lineage originated in Africa, but answers are hampered by the scarcity of Mio-Pliocene paleontological sites. To help fill these gaps, the Paleo-Primate Project Gorongosa, a multidisciplinary research initiative on human origins, was...

The giraffid fossils recovered from ~ 2.8–2.6 million year old (Ma) sediments from Lee Adoyta, Ledi-Geraru, Ethiopia, are described here. Sivatherium maurusium and Giraffa cf. G. gracilis are the two identified taxa, with the former being more abundant than the latter. We interpret this skew of relative abundance to be of paleoenvironmental signifi...

It has long been hypothesized that the transition from Australopithecus to Homo in eastern Africa was linked to the spread of open and arid environments near the Plio−Pleistocene boundary, but data for the latest Pliocene are scarce. Here we present new stable carbon isotope data from the late Pliocene mammalian fauna from Ledi-Geraru, in the lower...

The possibility of a causal relationship between Earth history processes and hominin evolution in Africa has been the subject of intensive paleoanthropological research for the last 25 years. One fundamental question is: can any geohistorical processes, in particular, climatic ones, be characterized with su cient precision to enable temporal correl...

Phreatic overgrowths on speleothems from Mallorca’s littoral caves are valuable markers of former sea-level stands. These carbonate encrustations form as CO2degasses from brackish cave water that is hydrologically connected to the Mediterranean Sea. This study uses time series analysis to document relationships between surface conditions of tempera...

Abstract Details Presentation Type: Poster Title: Selectivity among Early Pleistocene hominins: New evidence from the Koobi Fora Formation Authors: Kristen Tuosto; Samantha Ascoli; David Braun; Susana Carvalho; Rene Bobe; Mark Sier; Jonathan Wynn; Jack Harris; Matthew Caruana; David Patterson Abstract: Current perspectives on technology of the Ea...

Australopithecus anamensis is the earliest known species of Australopithecus and possibly the earliest obligate biped. The Omo-Turkana basin (ca. 4 Ma) preserves an exceptional record of A. anamensis. Most fossils attributed to this species within the basin have been found at Kanapoi (~75%), some have been discovered at Allia Bay (~25%) and no homi...

One approach to understanding the context of changes in hominin paleodiets is to examine the paleodiets and paleohabitats of contemporaneous mammalian taxa. Recent carbon isotopic studies suggest that the middle Pliocene was marked by a major shift in hominin diets, characterized by a significant increase in C4 foods in Australopithecus-grade speci...

A comprehensive survey of dissolved organic carbon (DOC) and chromophoric dissolved organic matter (CDOM) was conducted in the Canada and Makarov Basins and adjacent seas during 2010–2012 to investigate the dynamics of dissolved organic matter (DOM) in the Arctic Ocean. Sources and distributions of DOM in polar surface waters were very heterogeneou...

During three years of study (2010-2012), the western Arctic Ocean was found to have unique aragonite saturation profiles with up to three distinct aragonite undersaturation zones. This complexity is produced as inflow of Atlantic- and Pacific-derived water masses mix with Arctic-derived waters, which are further modified by physiochemical and biolo...

Fewstudies have attributed δ15N values of guano to a factor other than diet. A δ15N record obtained froma 1.5-m core of bat guano deposit from Zidită Cave (western Romania) provides a record of anthropogenic and climatic influence on the regional nitrogen pool. Nitrogen content is nearly constant (%N N 9) for over 1 m of the core, indicating limite...

The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to wh...

Large benthic foraminifera (LBF) are prolific producers of calcium carbonate sediments in shallow, tropical environments that are being influenced by ocean acidification (OA). Two LBF species, Amphistegina gibbosa (Order Rotaliida) with low-Mg calcite tests and Archaias angulatus (Order Miliolida) with high-Mg calcite tests, were studied to assess...

The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to wh...

Evidence for C 4-dominated savanna environments, which have often been linked to the origins of the genus Homo, is not documented in eastern Africa until ~2 Ma based on evidence from the Omo-Turkana Basin. The critical period for understanding the origins of Homo, the latest Pliocene (~3.0-2.6 Ma), however, has been poorly represented in the fossil...

Large benthic Foraminifera (Protista), which live predominantly in shallow tropical seas, are prolific producers of carbonate sediments and thus may be impacted by ocean acidification. Ocean acidification models project that the global average pH of the surface ocean will decline from a current value of 8.1 in 2015 ([CO2atm] ~400 ppm) to 7.6 in 214...

Understanding patterns of human evolution across space and time requires synthesizing data collected by independent research teams, and this effort is part of a larger trend to develop cyber infrastructure and e-science initiatives.[1] At present, paleoanthropology cannot easily answer basic questions about the total number of fossils and artifacts...

Karst estuaries represent unique systems created by freshwater inputs that flow directly into the sea through karst conduits and/or matrices. In order to determine the characteristics of a karst estuary resulting from the brackish discharge of Double Keyhole Spring into the Gulf of Mexico, we monitored short-term tidal fluctuations, long-term rainf...

A common, but not universal, effect of ocean acidification on benthic foraminifera is a reduction in the growth rate. The miliolid Archaias angulatus is a high-Mg (>4 mole% MgCO3), symbiont-bearing, soritid benthic foraminifer that contributes to Caribbean reef carbonate sediments. A laboratory culture study assessed the effects of reduced pH on th...

Widespread burning of mixed tree–grass ecosystems represents the major natural locus of pyrogenic carbon (PyC) production. PyC is a significant, pervasive and yet poorly understood "slow-cycling" form of carbon present in the atmosphere, hydrosphere, soils and sediments. We conducted 16 experimental burns on a rainfall transect through northern Aus...

We provide sedimentological, geochemical, mineral magnetic, stable carbon isotope, charcoal, and pollen-based evidence from a guano/clay sequence in Gaura cu Muscă Cave (SW Romania), from which we deduced that from ~ 1230 BC to ~ AD 1240 climate oscillated between wet and dry. From ~ 1230 BC to AD 1000 the climate was wetter than the present, promp...

Widespread burning of mixed tree-grass ecosystems represents the major natural locus of pyrogenic carbon (PyC) production. PyC is a significant, pervasive, and yet poorly understood "slow-cycling" form of carbon present in the atmosphere, hydrosphere, soils and sediments. We conducted sixteen experimental burns on a rainfall transect in northern Au...

Dating to more than four million years ago (Ma), the Mursi Formation is among the oldest of the Plio-Pleistocene Omo Group deposits in the lower Omo Valley of southwestern Ethiopia. The sedimentary sequence is exposed along a strip ∼35 km by 4 km, but it has received relatively little attention due to the difficult access to this area. Although exp...

Pyrogenic carbon (PyC; includes soot, char, black carbon, and biochar) is produced by the incomplete combustion of organic matter accompanying biomass burning and fossil fuel consumption. PyC is pervasive in the environment, distributed throughout the atmosphere as well as soils, sediments, and water in both the marine and terrestrial environment....

The δ13C values of 23 unevenly spaced guano samples from a 17-cm long clay sediment profile in Gaura cu Musc ă Cave (GM), in SW Romania, made it possible to preliminarily characterize the Medieval Warm Period summer hydroclimate regime. The beginning of the sequence (AD 990) was rather wet for more than a century, before becoming progressively drie...

Phreatic overgrowths on speleothems (POS) precipitate at the air-water interface in the littoral caves of Mallorca, Spain. Mainly composed of calcite, aragonite POS are also observed in specific locations. To characterize the geochemical environment of the brackish upper water column, water samples and salinity values were collected from water prof...

The original article has been published inadvertently with some errors in the equation under section Carbon isotope composition and Fig. 2. The corrected equation and Fig. 2 are given below.

Fontes-Villalba et al. (1) correctly observe that carbon isotope ratios in tooth enamel do not speak directly to plant versus animal food ingestion. Carbon isotope ratio data are useful for quantifying the consumption of C3- or C4-derived carbon, whether it comes directly from C3 or C4 plants or indirectly through consumption of animals that eat th...

Marine surface waters are being acidified due to uptake of anthropogenic carbon dioxide, resulting in surface ocean areas of undersaturation with respect to carbonate minerals, including aragonite. In the Arctic Ocean, acidification is expected to occur at an accelerated rate with respect to the global oceans, but a paucity of baseline data has lim...

The Diana Cave in SW Romania develops along a fault line and hosts a spring of hot (Tavg = 51 °C), sulfate-rich, sodium-calcium-chloride bearing water of near-neutral pH. Abundant steam and H2S rises from the thermal water to condensate on the walls and ceiling of the cave. The sulfuric acid produced by H2S oxidation/hydrolysis causes a strong acid...

Carbon isotope studies of early hominins from southern Africa showed that their diets differed markedly from the diets of extant apes. Only recently, however, has a major influx of isotopic data from eastern Africa allowed for broad taxonomic, temporal, and regional comparisons among hominins. Before 4 Ma, hominins had diets that were dominated by...

The enhanced dietary flexibility of early hominins to include consumption of C4/crassulacean acid metabolism (CAM) foods (i.e., foods derived from grasses, sedges, and succulents common in tropical savannas and deserts) likely represents a significant ecological and behavioral distinction from both extant great apes and the last common ancestor tha...

The proposed dietary pattern of extinct Late Pleistocene cave bears (Ursus spelaeus Rosenmüller, 1794) has become controversial, as some authors have suggested that they were strictly vegetarian, whereas others maintain they were omnivores that at times ate large amounts of animal protein. We evaluated these alternatives by compiling stable isotope...

Testing hypotheses linking environmental change and human evolution requires detailed climatic, tectonic and hydrographic records for the areas of interest. In eastern Africa, stratigraphically continuous lake beds often occur near important fossil hominin and artifact sites, providing an opportunity to reconstruct paleoenvironmental conditions at...

A wealth of data has accumulated over the past decade on the links between the North Atlantic (NA) climate and ocean variability and its influence on the European climate. However, most of the studies have been restricted to the area in the immediate vicinity of the NA, with little or no data existing west of the Alps. This region lies at both the...

A calibration study of oxygen and hydrogen isotopic composition from precipitation and cave dripwater was conducted in west-central Florida at Legend Cave during 2007–2008. This study was performed to better understand how modern precipitation patterns can be discerned through examination of cave dripwater and speleothem calcite for paleoclimate re...

Analyses of the isotope ratios of naturally existing materials have increasingly been used to reconstruct paleoenvironmental and paleoclimatic conditions. In this study carbon (C) and oxygen (O) isotopic composition of bioapatite from fossil tooth enamel is used to reconstruct Pliocene environmental and climatic changes at Galili, in the Awash vall...

Traditionally, beer contains 4 simple ingredients: water, barley, hops and yeast. Each of these ingredients used in the brewing process contributes some combination of a number of "traditional" stable isotopes (i.e., isotopes of H, C, O, N and S) to the final product. As an educational exercise in an "Analytical Techniques in Geology" course, a gro...