In situ forest with lycopsid trees bearing lobed rhizomorphs from the Upper Devonian of Lincheng, China.

The earliest forests in the Devonian were reported from only four localities worldwide. The tree lycopsids, sometimes as the primary elements of Devonian forests, had evolved several types of rooting systems. In recent years, we found and excavated a Late Devonian (Famennian, 374-359 Ma) lycopsid forest from Zhejiang Province, China. The fossil forest occurs at seven locations of Lincheng Town of Changxing County and mainly consists of in situ small tree lycopsid (Heliodendron longshanense gen. et sp. nov.) stems usually connected to lobed cormose rhizomorphs. The four short lobes of each rhizomorph often branch once and bear roots arranged radially. Allometry is observed between the trunk diameter of Heliodendron and the length of its rhizomorphic lobes, indicating that the trunk develops later than the rhizomorph in tree lycopsid plants. The Devonian witnessed the transformation from clastic nonlycopsid dominated forests to Carboniferous swampy forests dominated by giant lycopsid trees. These trees form a multigenerational community, as shown by the in situ preserved stems at various levels within the same area due to frequent sedimentation events.

Unveiling Challenging Microbial Fossil Biosignatures from Rio Tinto with Micro-to-Nanoscale Chemical and Ultrastructural Imaging.

Understanding the nature and preservation of microbial traces in extreme environments is crucial for reconstructing Earth's early biosphere and for the search for life on other planets or moons. At Rio Tinto, southwestern Spain, ferric oxide and sulfate deposits similar to those discovered at Meridiani Planum, Mars, entomb a diversity of fossilized organisms, despite chemical conditions commonly thought to be challenging for life and fossil preservation. Investigating this unique fossil microbiota can elucidate ancient extremophile communities and the preservation of biosignatures in acidic environments on Earth and, potentially, Mars. In this study, we use an innovative multiscale approach that combines the state-of-the-art synchrotron X-ray nanoimaging methods of ptychographic X-ray computed laminography and nano-X-ray fluorescence to reveal Rio Tinto's microfossils at subcellular resolution. The unprecedented nanoscale views of several different specimens within their geological and geochemical contexts reveal novel intricacies of preserved microbial communities. Different morphotypes, ecological interactions, and possible taxonomic affinities were inferred based on qualitative and quantitative 3D ultrastructural information, whereas diagenetic processes and metabolic affinities were inferred from complementary chemical information. Our integrated nano-to-microscale analytical approach revealed previously invisible microbial and mineral interactions, which complemented and filled a gap of spatial resolution in conventional methods. Ultimately, this study contributes to the challenge of deciphering the faint chemical and morphological biosignatures that can indicate life's presence on the early Earth and on distant worlds.

Foveapeltis gen. nov., an unusual cleroid genus with large hypomeral cavities from mid-Cretaceous amber (Coleoptera: Cleroidea).

Beetles have a remote evolutionary history dating back to the Carboniferous, with Mesozoic fossils playing a pivotal role in elucidating the early evolution of extant families. Despite their exceptional preservation in amber, deciphering the systematic positions of Mesozoic trogossitid-like beetles remains challenging. Here, we describe and illustrate a new trogossitid-like lineage from mid-Cretaceous Kachin amber, Foveapeltis rutai Li, Kolibác, Liu & Cai, gen. et sp. nov. Foveapeltis stands out within the Cleroidea due to the presence of a significant large cavity on each hypomeron. While the exact phylogenetic placement of Foveapeltis remains uncertain, we offer a discussion on its potential affinity based on our constrained phylogenetic analyses.

A dwarf conifer tree from the Triassic of Antarctica: the first fossil evidence of suppressed growth in a favorable climate?

BACKGROUND AND AIMS: The complexity of fossil forest ecosystems is difficult to reconstruct due to the fragmentary nature of the fossil record. However, detailed morpho-anatomical studies of well-preserved individual fossils can provide key information on tree growth and ecology, including in biomes with no modern analog such as the lush forests that developed in the polar regions during past greenhouse climatic episodes. METHODS: We describe an unusual-looking stem from Middle Triassic (ca 240 Ma) deposits of Antarctica with over 100 very narrow growth-rings and conspicuous persistent vascular traces through the wood. Sections of the specimen were prepared using the cellulose acetate peel technique to determine its systematic affinities and analyse its growth. KEY RESULTS: The new fossil shows similarities with the form genus Woodworthia and with conifer stems from the Triassic of Antarctica, and is assigned to the conifers. Vascular traces are interpreted as those of small branches retained on the trunk. Growth-ring analyses reveal one of the slowest growth rates reported in the fossil record, with an average of 0.2 mm/season. While the tree was growing within the Triassic polar circle, sedimentological data and growth-ring information from other fossil trees, including from the same locality, support the presence of favorable conditions in the region. CONCLUSIONS: The specimen is interpreted as a dwarf conifer tree that grew under a generally favorable regional climate but whose growth was suppressed due to stressful local site conditions. This is the first time that a tree with suppressed growth is identified as such in the fossil record, providing new insights on the structure of polar forests under greenhouse climates and, more generally, on the complexity of tree communities in deep time.

Headbutting through time: A review of this hypothesized behavior in "dome-headed" fossil taxa.

Headbutting is a combative behavior most popularly portrayed and exemplified in the extant bighorn sheep (Ovis canadensis). When behaviorally proposed in extinct taxa, these organisms are oft depicted Ovis-like as having used modified cranial structures to combatively slam into one another. The combative behavioral hypothesis of headbutting has a long and rich history in the vertebrate fossil literature (not just within Dinosauria), but the core of this behavioral hypothesis in fossil terrestrial vertebrates is associated with an enlarged osseous cranial dome-an osteological structure with essentially no current counterpart. One confounding issue found in the literature is that while the term "headbutting" sounds simplistic enough, little terminology has been used to describe this hypothesized behavior. And pertinent to this special issue, potential brain trauma and the merits of such proposed pugilism have been assessed largely from the potential deformation of the overlying osseous structure; despite the fact that extant taxa readily show that brain damage can and does occur without osteological compromise. Additionally, the extant taxa serving as the behavioral counterpart for comparison are critical, not only because of the combative behaviors and morphologies they display, but also the way they engage in such behavior. Sheep (Ovis), warthogs (Phacochoerus), and bison (Bison) all engage in various forms of "headbutting", but the cranial morphologies and the way each engages in combat is markedly different. To hypothesize that an extinct organism engaged in headbutting like an extant counterpart in theory implies specific striking:contacting surfaces, speed, velocity, and overall how that action was executed. This review examines the history and usage of the headbutting behavioral hypothesis in these dome-headed fossil taxa, their respective extant behavioral counterparts, and proposes a protocol for specific behavioral terms relating to headbutting to stem future confusion. We also discuss the disparate morphology of combative cranial structures in the fossil record, and the implications of headbutting-induced brain injury in extinct taxa. Finally, we conclude with some potential implications for artistic reconstructions of fossil taxa regarding this behavioral repertoire.

How can dry tropical forests respond to climate change? Predictions for key Non-Timber Forest Product species show different trends in India.

The present study provides an assessment of the distribution of key Non-Timber Forest Product species in India, namely Aegle marmelos (L.) Correa, Buchanania lanzan Spreng., Madhuca longifolia (J. Koenig ex L.) J. F. Macbr., Phyllanthus emblica L. and Terminalia bellirica (Gaertn.) Roxb. The suitable habitat was analyzed under current climate scenarios and subsequently, the future distribution (2050s and 2070s) was mapped under RCP 2.6 and 8.5 scenarios, along with the past distribution (mid-Holocene, ~ 6000 cal year BP) using the MaxEnt species distribution model. The distribution of all species is primarily driven by key bioclimatic factors, including annual precipitation (Bio_12), mean annual temperature (Bio_1), isothermality (Bio_3) and precipitation of the coldest quarter (Bio_19). The results indicate that the present distribution of these species is mainly centred in the Western Ghats regions, Central Highlands, North-eastern India and Siwalik hills. The current study suggests that under the future climate change, the suitable habitat for A. marmelos and T. bellirica is expected to increase while for B. lanzan, M. longifolia and P. emblica, it is projected to decline. A. marmelos and T. bellirica are anticipated to exhibit resilience to future climate changes and are expected to be minimally affected, while B. lanzan, M. longifolia and P. emblica are highly sensitive to high temperature and alteration in rainfall pattern expected under future climate changes. The projections of habitat suitability areas can be used as a valuable foundation for developing conservation and restoration strategies aimed at alleviating the climate change impacts on NTFP species.

Combined uranium-series and electron spin resonance dating from the Pliocene fossil sites of Aves and Milo's palaeocaves, Bolt's Farm, Cradle of Humankind, South Africa.

Bolt's Farm is the name given to a series of non-hominin bearing fossil sites that have often been suggested to be some of the oldest Pliocene sites in the Cradle of Humankind, South Africa. This article reports the results of the first combined Uranium-Series and Electron Spin Resonance (US-ESR) dating of bovid teeth at Milo's Cave and Aves Cave at Bolt's Farm. Both tooth enamel fragments and tooth enamel powder ages were presented for comparison. US-ESR, EU and LU models are calculated. Overall, the powder ages are consistent with previous uranium-lead and palaeomagnetic age estimates for the Aves Cave deposit, which suggest an age between ~3.15 and 2.61 Ma and provide the first ages for Milo's Cave dates to between ~3.1 and 2.7 Ma. The final ages were not overly dependent on the models used (US-ESR, LU or EU), which all overlap within error. These ages are all consistent with the biochronological age estimate (<3.4->2.6 Ma) based on the occurrence of Stage I Metridiochoerus andrewsi. Preliminary palaeomagnetic analysis from Milo's Cave indicates a reversal takes place at the site with predominantly intermediate directions, suggesting the deposit may date to the period between ~3.03 and 3.11 Ma within error of the ESR ages. This further suggests that there are no definitive examples of palaeocave deposits at Bolt's Farm older than 3.2 Ma. This research indicates that US-ESR dating has the potential to date fossil sites in the Cradle of Humankind to over 3 Ma. However, bulk sample analysis for US-ESR dating is recommended for sites over 3 Ma.

Can we see differences between the 14C activities of urban (Zagreb) and rural (Cvetkovic) sites (central Croatia)?

Radiocarbon (Δ14C) was measured for four years (2019-2022) in Zagreb (Croatia) and in Cvetkovic village near Jastrebarsko (Zagreb County, Croatia) to see whether there are differences between the city site and the rural one because of the fossil fuel combustion. The δ13CCO2 was measured as grab samples once in a month in period December 2020-November 2022. The bomb-produced 14C has been globally distributed across the planet, but the combustion of fossil fuels that do not contain 14C causes a local effect of lowering Δ14C. Zagreb is considered to be a location with heavy fossil fuel combustion as compared to the Cvetkovic (rural site). Monthly 14C activity at Zagreb is constantly below the 14C activity at Cvetkovic. Mean 14C activity at Zagreb (Δ14CZagreb = -18.4 ± 2.6 ‰) is lower than that in Cvetkovic (Δ14CCve = -2.9 ± 2.1 ‰) due to fossil fuel combustion in the city of Zagreb. This is especially pronounced during winter when the mean value in Zagreb is Δ14CZagreb = -26.0 ± 4.3 ‰ and in Cvetkovic Δ14CCve = -5.9 ± 3.4 ‰. Natural gas consumption was used as the proxy for fossil fuel combustion, and it shows better correlation with Δ14C in Zagreb than in Cvetkovic. The Δ14C difference, Δ14CCve ‒ Δ14CZagreb, becomes statistically negligible when natural gas consumption is small. No difference is observed on δ13CCO2; in Zagreb mean δ13CCO2 is -11.0 ± 1.3 ‰, and in Cvetkovic -11.4 ± 1.4 ‰. Lower δ13CCO2 values are observed in winter (Zagreb -11.9 ± 1.1 ‰, -12.2 ± 1.5 ‰ Cvetkovic) than in summer (-10.1 ± 0.8 ‰ vs. -10.4 ± 1.0 ‰) at both locations. Together with higher Δ14C in Cvetkovic, it indicates that at the area of Cvetkovic biogenic samples of modern origin (biomass, wood) as energy source for heating is more pronounced.

A geometric morphometric protocol to correct postmortem body arching in fossil fishes.

Postmortem body curvature introduces error in fish morphometric data. Compared to living fish, the causes of such body curvature in fossils may be due to additive taphonomic processes that have been widely studied. However, a protocol that helps to correct its effect upon morphometric data remains unexplored. Here, we test two different mathematical approaches (multivariate regression and the so-called 'unbending functions') available to tackle fish geometric morphometric data in two exceptionally preserved gonorynchiformes fossil fishes, Rubiesichthys gregalis and Gordichthys conquensis, from the Las Hoyas deposits (Early Cretaceous, Spain). Although both methods successfully correct body curvature (i.e., removing misleading geometric variation), our results show that traditional approaches applied in living fishes might not be appropriate to fossil ones, because of the additional anatomical alterations. Namely, the best result for 2D fossil fishes is achieved by correcting the arching of the specimens (mathematically "unbending" them). Ultimately, the effect of body curvature on morphometric data is largely taxon independent and morphological diversity mitigates its effect, but size is an important factor to take into account (because larger individuals tend to be less curved).

Flower Buds Confirmed in the Early Cretaceous of China.

The Yixian Formation (Lower Cretaceous) in China is famous worldwide for its fossils of early angiosperms, but there has been only one record of flower buds (Archaebuda lingyuanensis) hitherto, in which only the surface of the flower bud was documented while no internal details were known. Such a partial knowledge of flower buds hinders our understanding of the evolution of flowers, and this knowledge lacuna needs to be filled. Our new specimen was collected from an outcrop of the Yixian Formation (Barremian-Aptian, Lower Cretaceous) near Dawangzhangzi, Lingyuan, Liaoning, China. Our observations reveal a new fossil flower bud, Archaebuda cretaceae sp. nov., from the Lower Cretaceous of China. This new record of Archaebuda in the Yixian Formation not only confirms the truthful existence of the expected gynoecium (plus possible androecium) in a flower bud but also underscores the occurrence of typical flowers in the Early Cretaceous. This new information adds first-hand data to flower sexuality, pollination, and evolution.

Dynamic nexus among fossil fuels utilization, economic growth, and urbanization: a tri-regional selected countries analysis.

There are worldwide growing concerns about environmental issues such as global warming and climate change. Moreover, it is expected that there will be regional differences in environmental issues. Therefore, this study focuses on a tri-regional comparison: America, Europe, and Asia-Pacific. Previous literature has paid less attention to exploring regional comparisons while considering regional heterogeneity. Against this backdrop, this study delves into the dynamic relationship between fossil fuel utilization, economic growth, globalization, urbanization, and CO2 emissions to understand the environmental implications of these interconnected factors. The study period spans from 1990 to 2021. Additionally, it employed rigorous tests to confirm cross-sectional dependence and data heterogeneity, following methodologies proposed by Pesaran (2004, 2015) and Pesaran (2007), utilizing the CS-ARDL panel cointegration methodology by Chudik and Pesaran (2015). The results confirm long-term significant relationships among OC, NGC, FDI, and UR variables in both combined panels, with and without regional dummies. However, GDP and COC become insignificant in the long run in the dummy variables regression. Furthermore, the regional dummies were found to be negative but remain insignificant, possibly due to heterogeneous effects or unobserved factors influencing each region independently. Analysis by region reveals predominant coal consumption in Asia, higher oil consumption in America, and greater gas consumption in Europe. Economic growth and CO2 emissions are positive in Asia and America but negative in Europe, aligning with theories prioritizing growth over environmental concerns in Asia and America, and advocating for renewable energy adoption in Europe. Urbanization increases energy demand and emissions, supporting the environmental revolution theory, while FDI holds the potential to reduce CO2 emissions, as per the endogenous growth theory.

Armoured Lepidopteran Caterpillars Preserved in Non-Fossil Resins and What They Tell Us about the Fossil Preservation of Caterpillars.

Resin is a plastic-like product of trees. Older occurrences of such resin are referred to as amber and are considered fossil resin. Younger resins are termed copals. Even younger ones have been dubbed defaunation resins. Non-fossil resins remain in a terminological limbo, often referred to as "sub-fossils". We report two lepidopteran caterpillars preserved in non-fossil resin: one from Madagascar, one from Brazil. Prominent hairs (=setae) and spines (=spine-like setae) of the specimens make it likely that they represent larvae of Erebidae (e.g., tussock moths and others). So far, most known caterpillars preserved in resins are either "naked" or bear protective cases; only few are armoured with spines or hairs. In particular, long-haired caterpillars such as the ones reported here are so far almost absent. Only one specimen with comparable setae has been reported from 15-million-year-old Dominican amber, but no significant details of this specimen are accessible. We briefly also review the record of caterpillars known from the Holocene, recognising that it is very sparse. The new specimens demonstrate that very hairy caterpillars can readily be preserved in resins in fine detail. Furthermore, the specimens increase the known size range of caterpillars preserved in resins, with one measuring more than 12 mm.

Systematics Review and Phylogeny of Cyrtophyllitinae Zeuner, 1935 sensu Gorochov, Jarzembowski & Coram, 2006 (Ensifera, Haglidae), with Description of Two New Species.

A phylogeny of Cyrtophyllitinae Zeuner, 1935 sensu Gorochov, Jarzembowski & Coram, 2006, based on wing morphology, is presented including all genera. Cyrtophillitinae is found to be paraphyletic. Except for Cyrtophyllites rogeri Oppenheim, 1888, all other species were moved from the subfamily Cyrtophyllitinae (Hagloidea, Haglidae). Consequently, a new subfamily Archaboilinae subfam. nov. was erected and accommodates most of the previous cyrtophillitine taxa, except Cyrtophyllites rogeri. The type genus Archaboilus Martynov, 1937 of the new subfamily was designated; a new genus, Pararchaboilus gen. nov., was erected with the designation of type species Pararchaboilus cretaceus comb. nov. From the Middle Jurassic deposits of China, two new species, Archaboilus ornatus sp. nov. and Vitimoilus gigantus sp. nov., are described.

We can use our superpower to help end fossil fuel pollution and rise to the challenge of climate change.

In this commentary, we argue that health professionals can play a pivotal role in accelerating the adoption of public policies that will help communities, nations, and the world end fossil fuel pollution and rise to the challenges of climate change. We briefly describe our previously published research showing that communicating about fossil fuel pollution and the health relevance of climate change has many benefits in building public support for climate action. Most importantly, we make the case that because health professionals, especially medical doctors and other clinicians, are highly trusted, we collectively have a unique opportunity to bring people together across the political continuum to have constructive dialogues about the intertwined problems of fossil fuel pollution and climate change and what to do about them - even in the current hyper-partisan environment.

Atmospheric black carbon observations and its valley-mountain dynamics: Eastern cordillera of the central Andes of Peru.

Glacial bodies in the Peruvian Andes Mountains store and supply freshwater to hundreds of thousands of people in central Peru. Atmospheric black carbon (BC) is known to accelerate melting of snow and ice, in addition to contributing to air pollution and the health of people. Currently there is limited understanding on the sources and temporal variability of BC in valley and mountain environments in Peru. To address this problem, this study combined surface observations of BC collected during 2022-2023 with WRF model simulations and HYSPLIT trajectories to analyze the dispersion and sources of BC in valley and high elevation environments and the associated local atmospheric circulations. Results show high BC concentrations are associated with the valley-mountain wind system that occurs on both sides of the Huaytapallana mountain range. A pronounced circulation occurs on the western slopes of Huaytapallana when concentrations of BC increase during daylight hours, which transports atmospheric pollutants from cities in the Mantaro River Valley to the Huaytapallana mountain range. Low concentrations of BC are associated with circulations from the east that are channeled by the pronounced ravines of the Andes-Amazon transition. On average, during the season of highest BC concentrations (July-November), the relative contributions of fossil fuels are dominant to biomass burning at the valley observatory and are slightly lower at the Huaytapallana observatory. These results demonstrate the need to promote mitigation actions to reduce emissions of BC and air pollution associated with forest fires and local anthropogenic activity.

Edge chipping patterns in posterior teeth of hominins and apes.

Chip scars in fossil teeth are a lasting evidence that bears on human evolution. Chip dimensions in posterior teeth of hominins, apes and white-lipped peccary (Tayassu pecari) are measured from published occlusal images. The results are plotted as D/Dm vs. h/Dm, where h, D and Dm denote indent distance, chip width and mean tooth crown diameter. The hominin species follow a similar pattern where D/Dm monotonically increases up to h/Dm ≈ 0.3. The behavior for the apes is characterized by two phases. In the first, h/Dm monotonically increases up to h/Dm ≈ 0.26 while in the second (h/Dm ≈ 0.26 to 0.42), D/Dm experiences a drastic change in behavior. The interpretation of chip morphology is assisted by results from controlled spherical indentation tests on extracted human molars. This study shows that in addition to the commonly recognized chipping due to cusp loading, a chip may also initiate from the inner wall of the tooth's central fossa. Accordingly, it is suggested that the chipping in hominins generally initiates from a (worn) cusp while that in apes involves cusp loading up to h/Dm ≈ 0.26 and fossa loading thereafter. The behavior for T. pecari is much similar to that of the apes. The fossa chipping is facilitated by a consumption of hard, large-size diet (e.g., plants, roots, barks and nuts) and presence of broad central fossa, conditions that are met in apes. Finally, a simple expression for the critical chipping force Pch due to fossa loading is developed.

An extinct north American porcupine with a South American tail.

New World porcupines (Erethizontinae) originated in South America and dispersed into North America as part of the Great American Biotic Interchange (GABI) 3-4 million years ago.1 Extant prehensile-tailed porcupines (Coendou) today live in tropical forests of Central and South America.2,3 In contrast, North American porcupines (Erethizon dorsatum) are thought to be ecologically adapted to higher-latitude temperate forests, with a larger body, shorter tail, and diet that includes bark.4,5,6,7 Limited fossils8,9,10,11,12,13 have hindered our understanding of the timing of this ecological differentiation relative to intercontinental dispersal during the GABI and expansion into temperate habitats.14,15,16,17,18 Here, we describe functionally important features of the skeleton of the extinct Erethizon poyeri, the oldest nearly complete porcupine skeleton documented from North America, found in the early Pleistocene of Florida. It differs from extant E. dorsatum in having a long, prehensile tail, grasping foot, and lacking dental specializations for bark gnawing, similar to tropical Coendou. Results from phylogenetic analysis suggest that the more arboreal characteristics found in E. poyeri are ancestral for erethizontines. Only after it expanded into temperate, Nearctic habitats did Erethizon acquire the characteristic features that it is known for today. When combined with molecular estimates of divergence times, results suggest that Erethizon was ecologically similar to a larger species of Coendou when it crossed the Isthmus of Panama by the early Pleistocene. It is likely that the range of this more tropically adapted form was limited to a continuous forested biome that extended from South America through the Gulf Coast.

Morphological Characterization of Fossil Vitis L. Seeds from the Gelasian of Italy by Seed Image Analysis.

The discovery of well-preserved fossil Vitis L. seeds from the Gelasian stage in Italy has provided a unique opportunity to investigate the systematics of fossilized Vitis species. Through seed image analyses and elliptical Fourier transforms of fossil Vitis seeds from the sites Buronzo-Gifflenga and Castelletto Cervo II, we pointed out a strong relationship to the group of extant Eurasian Vitis species. However, classification analyses highlighted challenges in accurately assigning the fossil grape seeds to specific modern species. Morphological comparisons with modern Vitis species revealed striking similarities between the fossil seeds and V. vinifera subsp. sylvestris, as well as several other wild species from Asia. This close morphological resemblance suggests the existence of a population of V. vinifera sensu lato in Northen Italy during the Gelasian. These findings contributed to our understanding of the evolution and the complex interplay between ancient and modern Vitis species.

Ancient Diseases in Vertebrates: Tumours through the Ages.

Paleo-oncology studies neoplastic diseases in fossilised animals, including human remains. Recent advancements have enabled more accurate diagnoses of ancient pathologies despite the inherent challenges in identifying tumours in fossils-such as the rarity of well-preserved specimens, the predominance of bone remains, and the difficulty in distinguishing neoplastic from non-neoplastic lesions. This study compiles reports of tumours in fossilised animals, highlighting that neoplasms are present in a wide range of vertebrates and drawing comparisons to modern instances of similar diseases. The findings underscore the multifactorial aetiology of tumours, which involves genetic, environmental, and lifestyle factors, and suggest that tumours have been around for at least 350 million years.

China's Fossil Fuel CO2 Emissions Estimated Using Surface Observations of Coemitted NO2.

Accurate estimates of fossil fuel CO2 (FFCO2) emissions are of great importance for climate prediction and mitigation regulations but remain a significant challenge for accounting methods relying on economic statistics and emission factors. In this study, we employed a regional data assimilation framework to assimilate in situ NO2 observations, allowing us to combine observation-constrained NOx emissions coemitted with FFCO2 and grid-specific CO2-to-NOx emission ratios to infer the daily FFCO2 emissions over China. The estimated national total for 2016 was 11.4 PgCO2·yr-1, with an uncertainty (1σ) of 1.5 PgCO2·yr-1 that accounted for errors associated with atmospheric transport, inversion framework parameters, and CO2-to-NOx emission ratios. Our findings indicated that widely used "bottom-up" emission inventories generally ignore numerous activity level statistics of FFCO2 related to energy industries and power plants in western China, whereas the inventories are significantly overestimated in developed regions and key urban areas owing to exaggerated emission factors and inexact spatial disaggregation. The optimized FFCO2 estimate exhibited more distinct seasonality with a significant increase in emissions in winter. These findings advance our understanding of the spatiotemporal regime of FFCO2 emissions in China.