Kevin T Uno

Harvard University | Harvard · Department of Human Evolutionary Biology

Strontium isotope ratios (87Sr/86Sr) of incrementally grown tissues have been used to study movement/migration in extinct megaherbivores. Despite growing interest in this tool, two challenges remain. The first is how the same primary input signal is recovered from different archives, such as tooth enamel and dentin, with different sampling methods....

Some 25 years ago Dan Fisher with Dave Fox suggested that primary isotope inputs could be modified during processes such as maturation of enamel. Subsequent work on modern mammals shows that isotope incorporation can be affected by multiple metabolic pools that can have isotope turnover half-lives of up to 0.5 years, and that maturation of enamel v...

Strontium isotope ratios (⁸⁷Sr/⁸⁶Sr) of incrementally grown tissues have been used to study movement and migration of animals. Despite advances in characterizing ⁸⁷Sr/⁸⁶Sr turnover [1], the 2-D geometry of turnover in the tooth enamel is still poorly understood. The relocation of a zoo elephant (Loxodonta africana) named Misha provided an exception...

How animals respond to seasonal resource availability has profound implications for their dietary flexibility and realized ecological niches. We sought to understand seasonal dietary niche partitioning in extant African suids using intra-tooth stable isotope analysis of enamel. We collected enamel samples from canines of red river hogs/bushpigs (Po...

The geological record encodes the relationship between climate and atmospheric carbon dioxide (CO 2 ) over long and short timescales, as well as potential drivers of evolutionary transitions. However, reconstructing CO 2 beyond direct measurements requires the use of paleoproxies and herein lies the challenge, as proxies differ in their assumptions...

Strontium isotope ratios (87Sr/86Sr) of incrementally grown tissues have been widely used to study movement ecology and migration of both extant and extinct animals. However, the timescale of 87Sr/86Sr incorporation from the environment into tissue and how it may influence data interpretation are still poorly understood. Using the relocation of a z...

The eastern Mediterranean sapropels, paced by insolation, provide a unique archive of African monsoon strength over the Late Neogene. However, the longer-term climate of this region lacks characterization within the context of changes in ice volume, sea surface temperature gradients, and terrestrial ecosystems. Here, we examine C28n-alkanoic acid l...

Strontium isotope ratios ( ⁸⁷ Sr/ ⁸⁶ Sr) of incrementally grown tissues have been widely used to study movement ecology and migration of animals. However, the time scale of ⁸⁷ Sr/ ⁸⁶ Sr incorporation from the environment into tissue and how it may influence data interpretation are still poorly understood. Using the relocation of a zoo elephant ( Lo...

During the middle Pliocene (~3.8e3.2 Ma), both Australopithecus afarensis and Kenyanthropus platyops are known from the Turkana Basin, but between 3.60 and 3.44 Ma, most hominin fossils are found on the west side of Lake Turkana. Here, we describe a new hominin locality (ET03-166/168, Area 129) from the east side of the lake, in the Lokochot Member...

Living hominoids are distinguished by upright torsos and versatile locomotion. It is hypothesized that these features evolved for feeding on fruit from terminal branches in forests. To investigate the evolutionary context of hominoid adaptive origins, we analyzed multiple paleoenvironmental proxies in conjunction with hominoid fossils from the Moro...

The assembly of Africa's iconic C4 grassland ecosystems is central to evolutionary interpretations of many mammal lineages, including hominins. C4 grasses are thought to have become ecologically dominant in Africa only after 10 million years ago (Ma). However, paleobotanical records older than 10 Ma are sparse, limiting assessment of the timing and...

Fire is a key ecosystem process in tropical and subtropical savannas, with a varying role that depends on hydroclimate but also on feedbacks between fire and vegetation. In savannas, fire response to changes in rainfall depends on mean annual rainfall: in arid and semi-arid systems, burned area increases as rainfall increases fuel amount, whereas i...

On page 697, in Figure 6A, the Y axis corresponds to δ18O and not to δ13C. Figure 6 is reproduced here.

We describe otter remains (Lutrinae Bonaparte, 1838) from the Plio-Pleistocene of the Lower Omo Valley of southwestern Ethiopia. We report isolated lower and upper teeth of Torolutra sp. dated to c. 3.3 Ma, dental specimens and a femur of Enhydriodon Falconer, 1868, attributed to a new species, dated between c. 3.4 Ma and 2.5 Ma, as well as a humer...

Primate palaeontologist and passionate advocate for diversity in human origins research.

The Baynunah Formation contains the only known late Miocene terrestrial fossils from the Arabian Peninsula. Based on renewed field work since 2002, we present paleoenvironmental and dietary reconstructions from carbon isotope data from plant wax biomarkers and carbon and oxygen isotope data from fossil tooth enamel in combination with previously pu...

Miocene localities in the Turkana Basin are known for contributions to the primate fossil record, and for preservation of the ecosystems that directly preceded the rise of modern African megafauna. While terrestrial climate records from the Plio-Pleistocene in East Africa are well resolved, data from the Miocene are comparatively sparse. The early...

The article presents evidence about the Middle Palaeolithic and Middle to Upper Palaeolithic transition interval in the karst area of the Danube Gorges in the Lower Danube Basin. We review the extant data and present new evidence from two recently investigated sites found on the Serbian side of the Danube River – Tabula Traiana and Dubočka-Kozja ca...

Characterizing eastern African environmental variability on orbital timescales is crucial to evaluating the hominin evolutionary response to past climate changes. However, there is a dearth of high-resolution, well-dated records of ecosystem dynamics from eastern Africa that cover long time intervals. In the last 1 Myr, there were significant anato...

Fire dynamics potentially account for the asynchronous timing of the expansion of C4 grasslands throughout the Mio‐Pliocene world. Yet how fire, climate, and ecosystems interacted in different settings remain poorly constrained because it is difficult to quantify fires and fuel source over these timescales. Here, we apply molecular proxies for fire...

Modern tropical and subtropical C4 grasslands and savannas were established during the late‐Miocene and Pliocene, over 20 Myr after evolutionary originations of the C4 photosynthetic pathway. This lag suggests environmental factors first limited and then favored C4 plants. Here, we examine the timing and drivers for the establishment of C4 grasslan...

The KNM-ER 2598 occipital is among the oldest fossils attributed to Homo erectus but questions have been raised about whether it may derive from a younger horizon. Here we report on efforts to relocate the KNM-ER 2598 locality and investigate its paleontological and geological context. Although located in a different East Turkana collection area (A...

The Baynunah Formation contains the only known late Miocene terrestrial fossils from the Arabian Peninsula. Based on renewed field work since 2002, we present paleoenvironmental and dietary reconstructions from carbon isotope data from plant wax biomarkers and carbon and oxygen isotope data from fossil tooth enamel in combination with previously pu...

The assembly of Africa’s iconic C4 grassland and savanna ecosystems is central to evolutionary interpretations of many mammals, including hominins. Based largely on pollen, biomarkers, and isotopic data, C4 grasses are thought to have become ecologically dominant in Africa only after 10 Ma. However, paleobotanical records older than 10 Ma are spars...

Our understanding of the emergence and dispersal of the earliest tool-making hominins has been revolutionised in the last decade, with sites in eastern Africa and China pushing records of both events several hundred thousand years earlier than previously thought. In recent years, climate and environmental factors have been considered by many as pri...

Although climate change is considered to have been a large-scale driver of African human evolution, landscape scale shifts in ecological resources that may have shaped novel hominin adaptations are rarely investigated. We use well-dated, high-resolution, drill-core datasets to understand ecological dynamics associated with a major adaptive transiti...

Intra-tooth stable isotope variations have been used to interpret seasonality and aridity in paleoenvironmental reconstructions of paleontological and archeological sites. However, most intra-tooth datasets only permit qualitative interpretations of seasonality, because the measured signal is attenuated due to the duration of enamel mineralization...

Stable isotope ratios in tissues of large mammalian herbivores record diet and climate information integrated over large spatial areas and can be used to study modern and fossil ecosystems. Sound interpretation of data requires that tissue growth rates be determined accurately and that ecological and behavioral variables that influence stable isoto...

Intratooth stable isotope profiles in enamel provide time series of dietary and environmental information that if correctly interpreted, serve as archives of seasonal variability in past environments. A major challenge in interpreting these profiles arises from time averaging imparted by enamel mineralization and developmental geometry, whereby the...

Grasslands expanded globally during the late Cenozoic and the development of these ecosystems shaped the evolution of many faunal groups, including our hominin ancestors. The emergence of these ecosystems has been dated in many regions, but the origins of the iconic African C4 savannah grasslands remain poorly known, as do the causal factors that l...

Terrestrial paleoenvironmental reconstructions from the Pliocene Epoch (5.3–2.6 Ma) of the Neogene Period are rare from the North American continental interior, but are important because they provide insight into the evolutionary context of modern landscapes and ecological systems. Pliocene marine records indicate that global climate was warmer and...

The Plio-Pleistocene transition marks the final collapse of Cenozoic warm intervals and a shift to extensive northern hemisphere glaciation. Records from the North American continental interior across this transition, however, are nearly absent. The Meade Basin, southwest Kansas, not only preserves deposits that span this interval but also contains...

The Oldowan site HWK EE (Olduvai Gorge, Tanzania) has yielded a large fossil and stone tool assemblage at the transition from Lower to Middle Bed II, ∼1.7 Ma. Integrated tooth wear and stable isotope analyses were performed on the three most abundant ungulate taxa from HWK EE, namely Alcelaphini, cf. Antidorcas recki (Antilopini) and Equus oldowaye...

The well-dated Pleistocene sediments at Olduvai Gorge have yielded a rich record of hominin fossils, stone tools, and vertebrate faunal remains that, taken together, provide insight to hominin behavior and paleoecology. Since 2008, the Olduvai Geochronology and Archaeology Project (OGAP) has undertaken extensive excavations in Bed II that have yiel...

Supplementary Data Tables for Uno et al, 2018, Large mammal diets and paleoecology across the Oldowan-Acheulean transition at Olduvai Gorge, Tanzania from stable isotope and tooth wear analyses

Significance C-14 dating methods can be used to determine the time of death of wildlife products. We evaluate poaching patterns of elephants in Africa by using ¹⁴ C to determine lag time between elephant death and recovery of ivory by law enforcement officials. Most ivory in recent seizures has lag times of less than 3 y. Lag times for ivory origin...

Reconstructing vegetation at hominin fossil sites provides us critical information about hominin palaeoenvironments and the potential role of climate in their evolution. Here we reconstruct vegetation from carbon isotopes of plant wax biomarkers in sediments of the Nachukui Formation in the Turkana Basin. Plant wax biomarkers were extracted from sa...

The evolution of C4 grassland ecosystems in eastern Africa has been intensely studied because of the potential influence of vegetation on mammalian evolution, including that of our own lineage, hominins. Although a handful of sparse vegetation records exists from middle and early Miocene terrestrial fossil sites, there is no comprehensive record of...

Understanding the origin of modern communities is a fundamental goal of ecology, but reconstructing communities with durations of 103–106 years requires data from the fossil record. Early Pliocene to latest Pleistocene faunas and sediments in the Meade Basin and modern soils and rodents from the same area are used to examine the role of environment...

Objective: Archaeological remains strongly suggest that the Holocene Japanese hunter-gatherers, the Jomon people, utilized terrestrial plants as their primary food source. However, carbon and nitrogen isotope analysis of bone collagen indicates that they primarily exploited marine resources. We hypothesize that this inconsistency stems from the ro...

Significance Stable carbon isotopes give diet information for both modern and fossil mammals and can be used to classify diets as C 4 grazers, C 3 –C 4 mixed, or C 3 browsers. We show that diets of some major African herbivore lineages have significantly changed over the past 4 million years by comparing fossils from the Turkana Basin in Kenya with...

Dietary analyses of herbivorous mammals are important for paleoecological reconstruction. Several methods applicable to fossil teeth have been developed lately. The mesowear method based on wear-induced occlusal shape and relief of ungulate molars has proven to be a robust method for dietary analysis. In its original form it can only be used for se...

We present dental enamel stable carbon and oxygen isotope data, histological analyses of daily cross striations and perikymata, and microwear data of Late Miocene primates Indopithecus and Sivaladapis nagrii and an early Pleistocene primate Theropithecus delsoni, known from the Indian Siwaliks. The results indicate that the Late Miocene giant ape I...