Marine microfossils: Tiny archives of ocean changes through deep time.

Microorganisms have inhabited the oceans since the dawn of Earth. Some of them have organic walls and some produce mineral tests that are usually composed of carbonate minerals or silica. They can therefore be preserved with original parts during sedimentary deposition or fossilized through permineralization or carbonization processes. The most common marine fossil groups studied by micropaleontologists are cyanobacteria, coccolithophores, dinoflagellates, diatoms, silicoflagellates, radiolarians, foraminifers, red and green algae, ostracods, and pteropods. Dormant or reproductive cysts can also be used for determinations of the fossil microbiota. Microfossils can be studied in petrographic slides prepared from rocks or separated from loosely consolidated rocks by disaggregation or dissolution and wet sieving. Their presence is sometimes recognized by biomarkers. Transmitted light microscopy and reflected light stereomicroscopy are necessary for micropaleontological studies whereas scanning electronic microscopy (SEM) aids research on the tiniest fossils and reveals fine skeletal details. Microorganisms have influenced the oxygenation of water and the atmosphere, as well as Earth's carbon cycle and have contributed to the formation of sedimentary rocks. By studying microfossils, paleontologists depict the age of the rock and identify depositional environments. Such studies help us recognize periods of stress in Earth's history and understand their influence on living organisms. Biogenic rocks, made of microfossils, can be used as raw materials, such as fossil fuels, building stone, or additives for the food industry, agricultural, or cosmetic purposes.

A 4.3-million-year-old Australopithecus anamensis mandible from Ileret, East Turkana, Kenya, and its paleoenvironmental context.

A hominin mandible, KNM-ER 63000, and associated vertebrate remains were recovered in 2011 from Area 40 in East Turkana, Kenya. Tephrostratigraphic and magnetostratigraphic analyses indicate that these fossils date to ∼4.3 Ma. KNM-ER 63000 consists of articulating but worn and weathered mandibular corpora, with a broken right M2 crown and alveoli preserved at other tooth positions. Despite extensive damage, KNM-ER 63000 preserves diagnostic anatomy permitting attribution to Australopithecus anamensis. It can be distinguished from Australopithecus afarensis by its strongly inclined symphyseal axis with a basally convex, 'cut-away' external surface, a lateral corpus that sweeps inferomedially beneath the canine-premolar row, and alignment of the canine alveolus with the postcanine axis. KNM-ER 63000 is distinguished from Ardipithecus ramidus by its thick mandibular corpus and large M2 crown. The functional trait structure and enamel's stable carbon isotopic composition of the Area 40 large-mammal community suggests an environment comparable to Kanapoi and other ∼4.5-4 Ma eastern African sites that would have offered Au. anamensis access to both C3 and C4 food resources. With an age of ∼4.3 Ma, KNM-ER 63000 is the oldest known specimen of Au. anamensis, predating the Kanapoi and Asa Issie samples by at least ∼100 kyr. This specimen extends the known temporal range of Au. anamensis and places it in temporal overlap with fossils of Ar. ramidus from Gona, Ethiopia. The morphology of KNM-ER 63000 indicates that the reconfigured masticatory system differentiating basal hominins from the earliest australopiths existed in the narrow temporal window, if any, separating the two. The very close temporal juxtaposition of these significant morphological and adaptive differences implies that Ar. ramidus was a relative rather than a direct phyletic ancestor of earliest Australopithecus.

Aliphatic and polycyclic aromatic compounds in coal and coal-based solid wastes: Relationship with coal-forming paleoenvironment and implications for environmental pollution.

In this study, coal and coal-based solid wastes (coal gangue, fly ash, bottom ash, desulfurized gypsum and tar residue) were collected from major coal mines, power plants and coking plants in Lianghuai mining area (LH), China, and were analyzed for 76 polycyclic aromatic compounds (PACs), 27 n-alkanes and 2 isoprenoids (phytane and pristane). The total n-alkanes concentrations and ∑76 PACs in raw coals (640 ± 600 and 180 ± 87 µg/g) were higher than those in coal-based solid wastes (47 ± 40 and 24 ± 25 µg/g), but were lower than those in tar residue (3700 and 63,000 µg/g). It was discovered that the depositional paleoenvironment in LH was mostly a lacustrine and freshwater environment with oxidizing conditions and mixed organic matter input, but the Huainan coalfield had stronger oxidizing conditions and more input of terrestrial organic matter than that of the Huaibei coalfield. Alkylated PACs made up 56 ± 12 % of the ∑76PACs in raw coals, whereas solid wastes mainly consisted of 16 EPA PAHs (66 ± 16 %). Coal combustion and gangue weathering altered the structural properties of n-alkanes and PACs, resulting in a significant loss of n-alkanes and PACs, a higher proportion of parent PACs, and an increased abundance of short n-alkanes in the products (No apparent change of n-alkanes composition was observed through gangue weathering). The toxicity of PACs in raw coal and its solid wastes in LH from high to low was tar residue, raw coal, coal gangue, and coal-fired products. This investigation further confirmed that traditional diagnostic ratios may distort source information, and that they should not be used to assess PACs sources from raw coal particles or coal gangues, but rather to identify combustion sources near the point source. In addition, Retene/(Retene + Chrysene) < 0.03 may indicate direct contamination of raw coal particles.

Exploring Paleogene Tibet's warm temperate environments through target enrichment and phylogenetic niche modelling of Himalayan spiny frogs (Paini, Dicroglossidae).

The Cenozoic topographic development of the Himalaya-Tibet orogen (HTO) substantially affected the paleoenvironment and biodiversity patterns of High Asia. However, concepts on the evolution and paleoenvironmental history of the HTO differ massively in timing, elevational increase and sequence of surface uplift of the different elements of the orogen. Using target enrichment of a large set of transcriptome-derived markers, ancestral range estimation and paleoclimatic niche modelling, we assess a recently proposed concept of a warm temperate paleo-Tibet in Asian spiny frogs of the tribe Paini and reconstruct their historical biogeography. That concept was previously developed in invertebrates. Because of their early evolutionary origin, low dispersal capacity, high degree of local endemism, and strict dependence on temperature and humidity, the cladogenesis of spiny frogs may echo the evolution of the HTO paleoenvironment. We show that diversification of main lineages occurred during the early to Mid-Miocene, while the evolution of alpine taxa started during the late Miocene/early Pliocene. Our distribution and niche modelling results indicate range shifts and niche stability that may explain the modern disjunct distributions of spiny frogs. They probably maintained their (sub)tropical or (warm)temperate preferences and moved out of the ancestral paleo-Tibetan area into the Himalaya as the climate shifted, as opposed to adapting in situ. Based on ancestral range estimation, we assume the existence of low-elevation, climatically suitable corridors across paleo-Tibet during the Miocene along the Kunlun, Qiangtang and/or Gangdese Shan. Our results contribute to a deeper understanding of the mechanisms and processes of faunal evolution in the HTO.

Late Paleocene paleoclimate recorded in fluid inclusion of halite in Subei basin, East China.

Salt deposits are indicative of relatively extreme climate events. However, due to insufficient independent temperature proxies, paleotemperature records obtained from salt deposition are still lack. The Paleocene evaporite sequence deposited in the Hongze Depression of Subei Basin of eastern China provides an important terrestrial sediment record during this period. In this study we present total of 488 homogenization temperature (Th) data of halite fluid inclusions from drilling core with different stratigraphic depth after detailed petrological observation. The obtained Th ranged from 17.7 °C to 52.3 °C, with the mean Th value of 34.1 °C that in good agreement with the previous studies of climatic proxies. Our study shows that primary fluid inclusions of halite can serve as a robust tool to construct the ancient earth surface temperature.

Mid-Holocene marine faunas from the Bangkok Clay deposits in Nakhon Nayok, the Central Plain of Thailand.

Based on several field investigations, many molluscan shells and chondrichthyan teeth, together with other invertebrate and actinopterygian remains were found from the marine Bangkok Clay deposits in Ongkharak, Nakhon Nayok, at a depth of ~ 5-7 m below the topsoil surface. Animal macrofossils recovered from these Holocene marine deposits were identified and their chronological context was investigated in order to reconstruct the paleoenvironments of the area at that time. The majority of marine fossils recovered from the site consist of molluscs, with a total of 63 species identified. Other invertebrate species include a stony coral, a mud lobster, barnacles, and a sea urchin. The vertebrates are represented by fish remains, including carcharhinid shark teeth from at least nine species, stingray and trichiurid teeth, and one sciaenid otolith. The molluscan fauna indicates that the paleoenvironments of the area corresponded to intertidal to sublittoral zones, where some areas were mangrove forests and intertidal mudflats. The fish fauna is dominated by the river shark Glyphis, indicating freshwater influences and possibly occasional brackish conditions. The carbon-14 analysis of mollusc and charcoal remains shows that deposition of the marine sediment sequence began during the mid-Holocene, spanning approximately from 8,800 to 5,300 cal yr BP. This study provides in-depth insights into the diversity of fishes, marine molluscs, and other invertebrates from the Bangkok Clay deposits, supporting the existence of a marine transgression onto the Lower Central Plain of Thailand during the mid-Holocene.

The Sequential Direct and Indirect Effects of Mountain Uplift, Climatic Niche, and Floral Trait Evolution on Diversification Dynamics in an Andean Plant Clade.

Why and how organismal lineages radiate is commonly studied through either assessing abiotic factors (biogeography, geomorphological processes, and climate) or biotic factors (traits and interactions). Despite increasing awareness that both abiotic and biotic processes may have important joint effects on diversification dynamics, few attempts have been made to quantify the relative importance and timing of these factors, and their potentially interlinked direct and indirect effects, on lineage diversification. We here combine assessments of historical biogeography, geomorphology, climatic niche, vegetative, and floral trait evolution to test whether these factors jointly, or in isolation, explain diversification dynamics of a Neotropical plant clade (Merianieae, Melastomataceae). After estimating ancestral areas and the changes in niche and trait disparity over time, we employ Phylogenetic Path Analyses as a synthesis tool to test eleven hypotheses on the individual direct and indirect effects of these factors on diversification rates. We find strongest support for interlinked effects of colonization of the uplifting Andes during the mid-Miocene and rapid abiotic climatic niche evolution in explaining a burst in diversification rate in Merianieae. Within Andean habitats, later increases in floral disparity allowed for the exploitation of wider pollination niches (i.e., shifts from bee to vertebrate pollinators), but did not affect diversification rates. Our approach of including both vegetative and floral trait evolution, rare in assessments of plant diversification in general, highlights that the evolution of woody habit and larger flowers preceded the colonization of the Andes, but was likely critical in enabling the rapid radiation in montane environments. Overall, and in concert with the idea that ecological opportunity is a key element of evolutionary radiations, our results suggest that a combination of rapid niche evolution and trait shifts was critical for the exploitation of newly available niche space in the Andes in the mid-Miocene. Further, our results emphasize the importance of incorporating both abiotic and biotic factors into the same analytical framework if we aim to quantify the relative and interlinked effects of these processes on diversification.

Oxygen isotopes in orangutan teeth reveal recent and ancient climate variation.

Studies of climate variation commonly rely on chemical and isotopic changes recorded in sequentially produced growth layers, such as in corals, shells, and tree rings, as well as in accretionary deposits-ice and sediment cores, and speleothems. Oxygen isotopic compositions (δ18O) of tooth enamel are a direct method of reconstructing environmental variation experienced by an individual animal. Here, we utilize long-forming orangutan dentitions (Pongo spp.) to probe recent and ancient rainfall trends on a weekly basis over ~3-11 years per individual. We first demonstrate the lack of any consistent isotopic enrichment effect during exclusive nursing, supporting the use of primate first molar teeth as environmental proxies. Comparisons of δ18O values (n=2016) in twelve molars from six modern Bornean and Sumatran orangutans reveal a high degree of overlap, with more consistent annual and bimodal rainfall patterns in the Sumatran individuals. Comparisons with fossil orangutan δ18O values (n=955 measurements from six molars) reveal similarities between modern and late Pleistocene fossil Sumatran individuals, but differences between modern and late Pleistocene/early Holocene Bornean orangutans. These suggest drier and more open environments with reduced monsoon intensity during this earlier period in northern Borneo, consistent with other Niah Caves studies and long-term speleothem δ18O records in the broader region. This approach can be extended to test hypotheses about the paleoenvironments that early humans encountered in southeast Asia.

When an animal drinks water, two naturally occurring variants of oxygen ­ known as oxygen-18 and oxygen-16 ­ are incorporated into its growing teeth. The ratio of these variants in water changes with temperature, rainfall and other environmental conditions and therefore can provide a record of the climate during an animal's life. Teeth tend to be well preserved as fossils, which makes it possible to gain insights into this climate record even millions of years after an animal's death. Orangutans are highly endangered great apes that today live in rainforests on the islands of Borneo and Sumatra. During a period of time known as the Pleistocene (around 2.6 million years to 12,000 years ago), these apes were more widely spread across Southeast Asia. Climate records from this area in the time before human-induced climate change are somewhat limited. Therefore, fossilized orangutan teeth offer a possible way to investigate past seasonal rainfall patterns and gain insight into the kind of environments early humans would have encountered. To address this question, Smith et al. measured oxygen-18 and oxygen-16 variants in thin slices of modern-day orangutan teeth using a specialized analytical system. This established that the teeth showed seasonal patterns consistent with recent rainfall trends, and that the ratio of these oxygen variants did not appear to be impacted by milk intake in young orangutans. These findings indicated that the oxygen variants could be a useful proxy for predicting prehistoric weather patterns from orangutan teeth. Further measurements of teeth from fossilized Sumatran orangutans showed broadly similar rainfall patterns to those of teeth from modern-day orangutans. On the other hand, fossilized teeth from Borneo suggested that the environment used to be drier, with less intense wet seasons. The approach developed by Smith et al. provides an opportunity for scientists to leverage new fossil discoveries as well as existing collections to investigate past environments. This could allow future research into how climate variation may have influenced the spread of early humans through the region, as well as the evolution of orangutans and other endangered animals.

Geochemical and mineralogical characteristics of shales from the early to middle Permian Dohol Formation in Peninsular Malaysia: Implications for organic matter enrichment, provenance, tectonic setting, palaeoweathering and paleoclimate.

The early to middle Permian Dohol Formation is characterized by a significant presence of shale deposits. While these shales exhibit a low potential to generate hydrocarbons, there is a need to ascertain the possible reasons for the low hydrocarbon generation potential. Also, there are several unidentified properties and attributes associated with these shales in terms of their inorganic geochemical characteristics and their mineralogy. This study is focused on using XRF, ICPMS, and SEM with EDX to determine the mineralogical and geochemical characteristics of these shales and use these data to discuss their provenance history and tectonic setting and interpret the paleoclimatic and paleoweathering conditions. The inorganic geochemical analysis shows that the shales from the Dohol Formation are from a felsic igneous source. The shales were also identified to be from a passive margin based on the bivariate plot of SiO2 vs log (K2O/Na2O) and several multidimensional diagram plots. The CIA and CIW data, as well as the A-CN-K plot, all point to a significant degree of chemical weathering, ranging from mild to intense. The Sr/Cu ratio and C-value, combined with various other geochemical proxies, indicate that the shales were formed in warm-humid climatic conditions. The SEM analysis shows that the samples are mainly composed of kaolinite and illite, and this result was supported by the EDX elemental composition. The high terrigenous influx of sediments, the oxic to sub-oxic conditions in which the sediments were deposited, and finally low marine productivity were found to be the reasons for the low TOC in the shales from the Dohol Formation.

The Angiosperm Terrestrial Revolution buffered ants against extinction.

With ~14,000 extant species, ants are ubiquitous and of tremendous ecological importance. They have undergone remarkable diversification throughout their evolutionary history. However, the drivers of their diversity dynamics are not well quantified or understood. Previous phylogenetic analyses have suggested patterns of diversity dynamics associated with the Angiosperm Terrestrial Revolution (ATR), but these studies have overlooked valuable information from the fossil record. To address this gap, we conducted a comprehensive analysis using a large dataset that includes both the ant fossil record (~24,000 individual occurrences) and neontological data (~14,000 occurrences), and tested four hypotheses proposed for ant diversification: co-diversification, competitive extinction, hyper-specialization, and buffered extinction. Taking into account biases in the fossil record, we found three distinct diversification periods (the latest Cretaceous, Eocene, and Oligo-Miocene) and one extinction period (Late Cretaceous). The competitive extinction hypothesis between stem and crown ants is not supported. Instead, we found support for the co-diversification, buffered extinction, and hyper-specialization hypotheses. The environmental changes of the ATR, mediated by the angiosperm radiation, likely played a critical role in buffering ants against extinction and favoring their diversification by providing new ecological niches, such as forest litter and arboreal nesting sites, and additional resources. We also hypothesize that the decline and extinction of stem ants during the Late Cretaceous was due to their hyper-specialized morphology, which limited their ability to expand their dietary niche in changing environments. This study highlights the importance of a holistic approach when studying the interplay between past environments and the evolutionary trajectories of organisms.

Microparticles from dental calculus disclose paleoenvironmental and palaeoecological records.

Plants have always represented a key element in landscape delineation. Indeed, plant diversity, whose distribution is influenced by geographic/climatic variability, has affected both environmental and human ecology. The present contribution represents a multi-proxy study focused on the detection of starch, pollen and non-pollen palynomorphs in ancient dental calculus collected from pre-historical individuals buried at La Sassa and Pila archaeological sites (Central Italy). The collected record suggested the potential use of plant taxa by the people living in Central Italy during the Copper-Middle Bronze Age and expanded the body of evidence reported by previous palynological and palaeoecological studies. The application of a microscopic approach provided information about domesticated crops and/or gathered wild plants and inferred considerations on ancient environments, water sources, and past health and diseases. Moreover, the research supplied data to define the natural resources (e.g., C4-plant intake) and the social use of the space during that period. Another important aspect was the finding of plant clues referable to woody habitats, characterised by broad-leaved deciduous taxa and generally indicative of a warm-temperate climate and grassy vegetation. Other unusual records (e.g., diatoms, brachysclereids) participated in defining the prehistoric ecological framework. Thus, this work provides an overview on the potential of the human dental calculus analysis to delineate some features of the ancient plant ecology and biodiversity.

Megafossils of Betulaceae from the Oligocene of Qaidam Basin and their paleoenvironmental and phytogeographic implications.

Understanding the paleoenvironment and phytogeographical history of the Tibetan Plateau, China relies on discovering new plant fossils. The Qaidam Basin has long been regarded as an ideal 'field laboratory' to investigate the paleoclimate and paleobiological evolution of the northern Tibetan Plateau. However, fossil angiosperms from the Qaidam Basin are rare, and our knowledge of its paleovegetation is poor. Here, we report fossil leaves and fruits of Betulaceae found from the Oligocene Shangganchaigou Formation of northwestern Qaidam Basin (Huatugou area). Comparative morphological analysis led us to assign the fruits to the Betula subgenus Betula and the leaves to Carpinus grandis. These findings, together with other reported fossil plants from the same locality, reveal a close floristic linkage between the Qaidam Basin and Europe during the Oligocene. The northern pathway of this floristic exchange may have crossed through the Qaidam Basin during the late Paleogene. This floristic linkage may have been facilitated by the continuous narrowing of the Turgai Strait and stronger westerlies, which transported moisture and provided favorable climatic conditions. Indeed, fossil plants collected from the Qaidam Basin suggest that during the Oligocene this region had warm and humid deciduous broad-leaf forest, which differs from the region's modern vegetation and indicates that the Qaidam Basin may have been a suitable region for these plants to flourish and spread during the Oligocene.

Lipid-based paleoecological and biogeochemical reconstruction of Store Saltsø, an extreme lacustrine system in SW Greenland.

Polar lakes harbour a unique biogeochemistry that reflects the implications of climatic fluctuations against a susceptible yet extreme environment. In addition to polar, Store Saltsø (Kangerlussuaq, southwestern Greenland) is an endorheic lake with alkaline and oligotrophic waters that host a distinctive ecology adapted to live in such particular physico-chemical and environmental conditions. By exploring the sedimentary record of Store Saltsø at a molecular and compound-specific isotopic level, we were able to understand its ecology and biogeochemical evolution upon climate change. We employed lipid biomarkers to identify biological sources and metabolic traits in different environmental samples (shore terrace, sediment core, and white precipitates at the shore), and their succession over time to reconstruct the lake paleobiology. Different molecular ratios and geochemical proxies provided further insights toward the evolution of environmental conditions in the frame of the deglaciation history of Kangerlussuaq. The relative abundance of terrestrial (i.e., plant derived) biomarkers (odd long-chain n-alkanes, even long-chain n-alkanols, and phytosterols) in the upper half of the shore terrace versus the relatively more present aquatic biomarkers (botryococcenes and long-chain alkenones) in its lower half revealed higher lake water levels in the past. Moreover, the virtual absence of organics in the deepest section of the sediment core (32-29 cm depth) suggested that the lake did not yet exist at the northwestern shore of Store Saltsø ∼5100 years ago. According to the relative abundance of lipid biomarkers detected in the adjacent section above (29-25 cm depth), we hypothesize that the northwestern shore of Store Saltsø formed ∼4900 years ago. By combining the molecular and compound-specific isotopic analysis of lipids in a ∼360 cm sedimentary sequence, we recreated the paleobiology and evolution of an extreme lacustrine environment suitable for the study of the limits of life and the effects of climate warming.

Aridity, availability of drinking water and freshwater foods, and hominin and archeological sites during the Late Pliocene-Early Pleistocene in the western region of the Turkana Basin (Kenya): A review.

Although the Turkana Basin is one of the driest regions of the East African Rift, its Plio-Pleistocene sediments are rich in freshwater vertebrates and invertebrates, providing evidence that freshwater resources were available to hominins in this region during the Plio-Pleistocene (4.2-0.7 Ma). Here we provide an overview of the hydroconnectivity of the Turkana Basin. We then review the period during which freshwater river and lake systems expanded into the western region of the Turkana Basin, where hominin and archeological sites have been discovered in sediments dating back to the Late Pliocene-Pleistocene. Freshwater conditions are reconstructed from river and lake sediments and the flora and micro- and macofauna they contain. Data synthesis suggests that drinking water and freshwater foods prevailed in the western region of the Turkana Basin at 4.20-3.98 Ma, 3.70-3.10 Ma, 2.53-2.22 Ma, then between 2.10 and 1.30 Ma and intermittently from 1.27 to 0.75 Ma. Milestones in hominin evolution occurred in this context, such as the first occurrence of Australopithecus anamensis (4.20-4.10 Ma) and Kenyanthropus platyops (3.50 Ma and 3.30-3.20 Ma), the presence of Paranthropus aethiopicus (2.53-2.45 Ma), early Homo (2.33 Ma), Paranthropus boisei (2.25 Ma and 1.77-1.72 Ma) and Homo ergaster/Homo erectus (1.75 Ma, 1.47-1.42 Ma and 1.10-0.90 Ma). Developments in hominin behavior also occurred during this timeframe, including the first known stone tools (3.30 Ma), the oldest Oldowan sites (2.34 Ma and 2.25 Ma) in the Turkana Basin, the earliest known evidence for the emergence of bifacial shaping in eastern Africa (1.80 Ma), and the first known Acheulean site (1.76 Ma). Our synthesis suggests that, diachronic variation in hydroconnectivity played a role on the amount of drinking water and freshwater foods available in the western region of the Turkana Basin, despite regional aridity.

Stratigraphic, sedimentological, geochemical, mineralogical and geochronological data characterizing the Upper Miocene sequence of the Turiec Basin, Western Carpathians (Central Europe).

The data included in this article specify the characteristics of the Upper Miocene fill of the Turiec Basin and served for reconstruction of temporal evolution of depositional systems in this intermontane basin located within the Western Carpathians (Central Europe). The borehole lithological log data were used to describe the stratigraphy of the Turiec Basin in geological sections and were gained in the Geofond archive of the State Geological Institute of Dionýz Stúr. The sedimentological data were acquired by field research applying facies analysis to nine outcrop sites. The outcrops served for grain size analyzes performed by sieving and laser diffraction, for geochemical analyzes using ICP-ES, ICP-MS and XRF, and for mineralogical analyzes of whole rock and clay fraction by XRD. Moreover, the muddy layers on outcrops served for collection of 31 samples for the authigenic 10Be/9Be dating. The geochronological data are presented by using five different initial ratios for calculation, determined within the Turiec Basin at the Late Pleistocene alluvial fan and river terrace sites as well as at two Holocene muddy floodplain sites. Another initial ratio data are gained from an Upper Miocene lacustrine succession dated independently by magnetostratigraphy in previous research. Finally, a summary of previously published strontium isotope data from the Turiec Basin is included. The interpretations of the data are provided in Sujan et al., (2023) Palaeogeography, Palaeoclimatology, Palaeoecology 628, 111746.

The firing temperatures of burnt clay from the Chinese neolithic cultural relics and its paleoenvironmental imprints.

The impact of human-induced fires on the surrounding environment has been particularly significant during the Anthropocene epoch. Neolithic burnt clay, which is widely distributed in the archaeological relics of ancient civilizations across the Eurasian continent, provides pivotal information about the ancient firing stories. However, understanding of the paleoenvironmental imprints of fire in burnt clay has been largely limited by the lack of sufficient analytical data on comprehensive knowledge of ancient firing conditions. In this study, a detailed magnetic analysis was conducted on burnt clay materials from a Neolithic site in Fujian, southeastern China, which presented a burnt clay-based record of the Neolithic firing temperature in relation to paleoenvironmental conditions. Based on magnetic analysis, the ancient firing temperature was determined to be approximately 620 °C, which is comparable with other records from Eurasian Neolithic sites. Frequency-dependent magnetic susceptibility provides alternative indicative information for ancient firing conditions in addition to conventional magnetic susceptibility. Furthermore, magnetic properties of burnt clay may decode the in-situ source characteristics with respect to geological background. In addition, a potential link between temporal variations in ancient firing temperatures in burnt clay and surrounding paleoenvironmental changes is tentatively interpreted by local environmental feedback of temperature-moisture conditions and anthropogenic activity. This study further confirms the archaeological potential of thermomagnetic properties as useful indicators in paleoenvironmental studies. More work combining paleoenvironmental and archaeological archives is critically essential to understand ancient firing history in the context of environmental conditions.

Elevational Goldilocks zone underlies the exceptional diversity of a large lizard radiation (Liolaemus; Liolaemidae).

Mountains are among the most biodiverse regions on the planet, and how these landforms shape diversification through the interaction of biological traits and geo-climatic dynamics is integral to understanding global biodiversity. In this study, we investigate the dual roles of climate change and mountain uplift on the evolution of a hyper-diverse radiation, Liolaemus lizards, with a spatially explicit model of diversification using a reconstruction of uplift and paleotemperature in central and southern South America. The diversification model captures a hotspot for Liolaemus around 40°S in lineages with low-dispersal ability and narrow niche breadths. Under the model, speciation rates are highest in low latitudes (<35°S) and mid elevations (~1,000 m), while extinction rates are highest at higher latitudes (>35°S) and higher elevations (>2,000 m). Temperature change through the Cenozoic explained variation in speciation and extinction rates through time and across different elevational bands. Our results point to the conditions of mid elevations being optimal for diversification (i.e., Goldilocks Zone), driven by the combination of (1) a complex topography that facilitates speciation during periods of climatic change, and (2) a relatively moderate climate that enables the persistence of ectothermic lineages and buffers species from extinction.

New paleopathological findings from the Quaternary of the Brazilian Intertropical Region expand the distribution of joint diseases for the South American megafauna.

OBJECTIVE: To evaluate pathological changes in fossils from the Brazilian Intertropical Region (BIR), expanding the records of previously reported diseases for representatives of the Quaternary South American megafauna, including taxa not studied in previous works. MATERIALS AND METHODS: We carried out a thorough macroscopic analysis of fifteen unpublished specimens belonging to representatives of the Quaternary megafauna of BIR to identify evidence of pathological alterations. RESULTS: Alterations included: osteophytes in Toxodontidae, Megatheridae and E. laurillardi; rough subchondral bone, bone overgrowth and bone erosion in E. laurillardi; slit-shaped subchondral depressions in Equidae and E. laurillardi; and a triangular-shaped porous lesion in Mylodontidae. CONCLUSIONS: The alterations found allowed the recognition of the first cases of osteoarthritis for Toxodontidae and articular depressions for Equidae, and new cases of both diseases in Eremotherium laurillardi; a new case of osteochondritis dissecans for Mylodontidae; potential new cases of calcium pyrophosphate deposition and spondyloarthropathy for E. laurillardi SIGNIFICANCE: Our results provide additional evidence that calcium pyrophosphate deposition disease was widely spread among species of the South American megafauna and suggest that osteochondritis dissecans may have been relatively common among ground sloths. LIMITATIONS: The identification of calcium pyrophosphate deposition and spondyloarthropathy in E. laurillardi are quite tentative because the evidence found is ambiguous and the number of examined specimens is limited.

Microvertebrate faunal assemblages of the Favel Formation (late Cenomanian-middle Turonian) of Manitoba, Canada.

Microvertebrate assemblages of the Upper Cretaceous (late Cenomanian to mid-Turonian) Favel Formation of Manitoba are formally described for the first time. New vertebrate occurrences from the Favel Formation include the actinopterygians Caturidae indet., cf. Albulidae incertae sedis, Micropycnodon kansasensis, Pachyrhizodus minimus, Protosphyraena sp., Thryptodus loomisi, chondrichthyans Ischyrhiza cf. mira, I. texana, Ptychodus marginalis, P. occidentalis, and P. rhombodus, the avian cf. Ichthyornis sp., the reptile Testudines indet., and an unknown taxon referred to as Vertebrate A. Changes in faunal occurrences throughout the formation suggest an offshore open marine environment for the lower and middle horizons and nearshore marine for the upper horizon, represent ing mid- and late stages of the Greenhorn third-order marine cycle. This newly described diversity increases biogeographic affinities of the late Cenomanian to mid-Turonian vertebrate assemblages of Manitoba with central WIS localities in South Dakota and Kansas, providing additional support for a central vertebrate biogeographic subprovince during late Cenomanian to early Turonian times, as well as WIS localities further south in Texas decreasing the gradient of the north-south or central-south community boundary during early and mid-Turonian times.

Preliminary description of a late Middle Pleistocene mammalian fauna prior to the extinction of Gigantopithecus blacki from the Yixiantian Cave, Guangxi ZAR, South China.

In recent years, nearly 20 cave sites with rich assemblages of mammalian fossils have been found and excavated in the Chongzuo area, Guangxi Zhuang Autonomous Region, China. Their ages are distributed throughout the entire Pleistocene Epoch. These discoveries have greatly facilitated our understanding of the evolution of the Stegodon-Ailuropoda fauna and the environmental context of human evolution in southern China. Here, we present a preliminary report on a diverse late Middle Pleistocene mammalian fauna from the Yixiantian Cave in southern China, which is a typical representative of the Stegodon-Ailuropoda fauna (sensu lato). The fossil mammals are represented by isolated dental remains only. In 2010 and 2011, two seasons of systematic excavations at the Yixiantian Cave yielded a total of 4,958 identifiable mammalian teeth. They were identified as belonging to 37 species and 6 orders of mammals. In addition, the tooth type of all the teeth representing each species was also determined where possible. A single fragmentary molar was identified as belonging to Gigantopithecus blacki, indicating that its population had declined sharply at this time and was on the brink of extinction. Description of the Yixiantian fauna will not only help better characterize the composition of the Stegodon-Ailuropoda fauna during the late Middle Pleistocene, but also clarify our understanding of the paleoenvironmental context at a time just prior to the extinction of G. blacki.