Knowing the past temperature of the Earth is crucial for understanding the mechanisms driving climate change and biosphere evolution, but there is significant debate about the range of past temperature variation. Previous interpretations, largely based on oxygen isotope records, suggest that global temperature has generally declined over the past 539 million years, but substantial uncertainties persist. In this study, we introduce an independent estimate for long-term Phanerozoic temperature trends based on a large database of chemical weathering indices from siliciclastic sedimentary rocks, globally upscaled using a state-of-the-art general circulation paleoclimate model. Our results imply that Phanerozoic global temperatures remained within 10-30 °C, and that Paleozoic oceans had comparable temperatures to Mesozoic and Cenozoic oceans, in contrast to previous work suggesting that they were anomalously hot. This finding supports the idea that negative feedback processes, such as silicate weathering, have maintained long-term global average temperatures within a relatively tight range, contributing to the continued long-term evolution of the biosphere.

Reconstructing the evolution of global climate zones since the Mesozoic is essential for understanding long-term climate change. Here, we apply a paleo-Ko & uml;ppen classification to a selected HadCM3 paleoclimate simulation series to produce global climate-zone maps from 252 Ma to the present at five-million-year intervals. These reconstructions capture spatiotemporal variations in the areal, latitudinal distribution, and elevational extent of climate zones through time. Using standardized climate-zone spatial metrics, we perform cluster analysis and identify three climate states: icehouse, wet greenhouse, and dry greenhouse. Compared with frameworks based solely on global mean surface temperature, this climate-zone-based classification captures additional hydro-climatic variability and provides a complementary perspective on global climate states. Correlation analyses furthur suggest that total radiative forcing is primarily associated with variations in meridional temperature gradients, whereas cryospheric and topographic effects are more closely linked to the extent of cold climates at high latitudes and/or high elevations. In contrast, paleogeographic configuration and solar forcing are more strongly associated with the distribution of arid and humid climate belts. Atmospheric CO2 shows associations with both temperature-and aridity-related indicators. Finally, within this climate-zone framework, the climatic significance of different sedimentary types is quantitatively and quantitatively reinterpreted, providing additional support for their use as paleoclimate indicators.

Literary world-building allows authors to experiment with their creation, changing features of imaginary worlds to contrast with the real world. In this sense, fictional world-building is a literary analogue to scientific models – simplified representations of the world. Merging the disparate disciplines of literary world-building and climate modelling, we present case studies of participatory culture, simulating the imaginary worlds of J.R.R. Tolkien, George R. R. Martin, and Robert Jordan, comparing our simulations to the original authors’ depictions. We also show how a climate model of an in-development fantasy world can guide world-building of new imaginary worlds, facilitating narrative immersion. Combining fantasy world-building and climate modeling offers the opportunity to fill gaps in imaginary worlds and draw pedagogical attention to the science of climate models, particularly in a classroom setting.

Warm, high-CO2 climates of Earth's past provide an opportunity to evaluate climate models under extreme forcing, and to explore mechanisms that lead to such warmth. One such time period is the early Eocene (similar to 56-41 million years ago), when global mean surface temperatures were similar to 15 degrees C higher than preindustrial, and CO2 concentrations were similar to 1500 ppmv. In this paper we present the experimental design for Phase 2 of the Eocene component of the Deep-time Model Intercomparison project (DeepMIP-Eocene-p2). The aim is to provide a framework for modelling groups to carry out a common set of simulations, thereby facilitating exploration of inter-model dependencies. The focus is on the early Eocene Climatic Optimum (EECO, similar to 53.3-49.1 million years ago). Relative to Phase 1 of DeepMIP-Eocene, we provide a new paleogeography (topography, bathymetry) derived from several recent independent reconstructions that focused on different regions, a new vegetation distribution derived by merging paleobotanical data with vegetation model simulations, and a new CO2 specification derived from recent re-evaluations of proxy data. The core set of simulations consists of a preindustrial control, an abrupt increase to 4 & times; preindustrial CO2 concentration from this preindustrial control, a standard control EECO simulation at 5 & times; preindustrial CO2 concentration, and an EECO simulation with preindustrial CO2 concentration. In addition to these core simulations, we suggest a suite of optional sensitivity studies, which allow the impact of various factors to be explored, such as topography/bathymetry, greenhouse gases, land-surface parameters, astronomical and solar forcings, and internal model parameters. The updated boundary conditions and guidance on initialisation and spinup in Phase 2 will allow more robust model-data comparisons, more accurate insights into mechanisms influencing early Eocene climate, and increased relevance for informing future climate change projections.

Abstract The red seaweed genus Ahnfeltia is an ancient lineage that has persisted for over 500 million years with remarkably limited diversification despite a global distribution in cold-temperate intertidal habitats. Compared to the highly diverse sister lineage, Rhodymeniophycidae, Ahnfeltia provides a unique system for investigating long-term evolutionary persistence in marine macroalgae. Here, we generated chromosome-scale genomes from five populations across three species and combined population genomics with paleogeographic niche modelling. Our results reveal remarkable genomic conservation, strong geographic isolation with limited gene flow, high homozygosity, and evidence of purifying selection. Niche projections indicate long-term stability and spatial connectivity of suitable cold-temperate habitats. These findings suggest that Ahnfeltia ’s persistence and limited diversification are linked to genomic constraints and stable ecological niches over geological timescales. This study provides new insights into the genomic basis of evolutionary stasis in ancient marine lineages and highlights potential vulnerability to ongoing climate change affecting cold-water coastal ecosystems.

Earth’s climate shows a remarkable variability on geological timescales, ranging from widespread glaciation to ice-free greenhouse conditions over the course of the Phanerozoic, i.e. the last 540 million years. Earth system modelling allows us to better understand and constrain the drivers of these changes and provides valuable reference data for other paleoclimate disciplines (e.g., chemistry, geology, hydrology). However, the sheer volume and complexity of these datasets often prevents direct access and use by non-modellers, limiting their benefits for large parts of our community.We present the online platform “climatearchive.org” to break down these barriers and provide intuitive access to paleoclimate data for everyone. More than 100 global coupled climate model simulations covering the entire Phanerozoic at the stage level build the backbone of the web application. Key climate variables (e.g. temperature, precipitation, vegetation and circulation) are displayed on a virtual globe in an intuitive three-dimensional environment and on a continuous time axis throughout the Phanerozoic. The software runs in any web browser — including smartphones — and promotes visual data exploration, streamlines model-data comparisons, and supports public outreach efforts. We discuss the current proof of concept and outline the future integration of new sources of model and geochemical proxy data to streamline and advance interdisciplinary paleoclimate research.We also present ongoing efforts for an integrated model-data synthesis to quantify changes in meridional and zonal temperature gradients throughout the Phanerozoic and to address the relative roles of individual forcings (greenhouse gases, solar, geography). While substantial effort has been made to quantify the evolution of global mean temperatures over the last 540 million years, changes in the large-scale temperature gradients and their causes are comparably less constrained. As a fundamental property of the climate system, changes in the spatial patterns of surface temperature play a critical role in controlling large-scale atmospheric and ocean circulation and influence hydrological, ecological, and land surface processes. The resulting best estimate product of meridional and zonal temperature gradients over the last 540 million years will represent a step change in our understanding of the drivers and consequences of past temperature gradient changes and will provide the community with a valuable resource for future climatological, geological, and ecological research.

The Tibetan and Iranian plateaus are the two most prominent orogenic plateaus on the present Earth built by continental collision. However, the timings of initial collision and suturing in the Himalaya and Zagros remain debated. In this Review, we summarize the timings, similarities and differences between the India–Eurasia collision and the Arabia–Eurasia collision, by comparing their sedimentary, magmatic, metamorphic, structural and palaeomagnetic records. The India–Eurasia collision is tightly constrained to have initiated in the central Himalaya at 65–59 Ma, possibly progressing towards the western and eastern Himalayas by 55–50 Ma. By contrast, the initial collision in the Zagros is loosely constrained to ~34 Ma, with a possibility of diachronous collision, younging to the southeast. Similarities between the two collisions include pre-collisional accretionary tectonism and magmatism, syn-collisional deformation and sedimentation, and crustal thickening. Apparent differences in lithospheric dynamics, deformation styles and metamorphism are attributed to variations in convergence rates, durations and magnitudes. Future research should focus on data-driven modelling and geophysical imaging beneath the Tibetan and Iranian plateaus to further quantify the geodynamic processes and driving forces contributing to continuous plate convergence, plateau formation and their surface impacts. The collision of the Indian, Arabian and Eurasian plates formed the Tibetan and Iranian plateaus, but its timing and processes remain debated. This Review explores the evidence behind initial collision estimates and discusses the tectonic and geodynamic implications.

The Miocene (∼23–5 Ma) experienced substantial paleogeographic changes, including the shoaling of the Panama Seaway and closure of the Tethys Seaway, which altered exchange pathways between the Pacific and Atlantic Oceans. Changes in continental configuration and topography likely also influenced global wind patterns. Here, we investigate how these changes affected surface wind‐driven gyre circulation and interbasin volume transport using 14 fully coupled climate model simulations of the early and middle Miocene. The North and South Atlantic gyres, along with the South Pacific gyre, are weaker in the Miocene simulations compared to pre‐industrial (PI), while the North Pacific gyres are stronger. These changes largely follow the wind stress curl and basin width changes. Westward flow through the Panama Seaway occurs only in early Miocene simulations when the Tethys Seaway is open and transports are strongly westward. As the Tethys transport declines, flow across the Panama Seaway gradually reverses from westward (into the Pacific) to eastward (into the Atlantic). In simulations with a closed Tethys Seaway, the Panama transport is consistently eastward. The Southern Hemisphere westerlies are weaker than PI in all simulations, contributing to a reduced Antarctic Circumpolar Current (ACC) in 11 of the 14 cases. In the remaining three, a stronger ACC is simulated, likely due to a combination of enhanced meridional density gradients and model‐dependent sensitivities. These findings highlight how changes in Miocene seaways and wind patterns reshaped ocean circulation, influencing interbasin exchange, thermohaline properties, and global climate.

Desert dust is a vital component of the Earth's climate system. The climate system regulates dust emission processes, such as sediment availability and wind entrainment, in various ways. Dust modulates the Earth's radiation balance, and wind-carried dust deposition provides essential nutrient iron to land and marine ecosystems. While dust science is well-developed for the modern and the Quaternary (the last 2.6 Ma), little investigation has been done for the Earth's deep time.Here, we present for the first time a continuous reconstruction of dust emissions throughout the Phanerozoic era (since 540 Ma ago), simulated by a newly developed dust emission model DUSTY, which is forced by the paleoclimate fields from the General Circulation Model HadCM3L. Our results show how dust emissions fluctuated over time with a stage-level resolution (approximately 5 Ma). We then diagnosed the controls of these fluctuations, highlighting that the non-vegetated area is the main contributor, which is controlled through precipitation levels. The ultimate dominating forcing is the paleogeography changes, whereas CO2 plays a marginal role. We compare our results with sediment evidence and find good agreement. Finally, we present ongoing work investigating further how dust deposition might have impacted ocean production and biogeochemistry through deep-geologic time.

The Asian summer monsoon (ASM) is a seasonal response of the coupled land-ocean-atmospheric system, which influences more than 60% of the world’s population. Although progress has been made in understanding the ASM variability and its prediction, the timing and governing factors for the ASM initiation are still debatable as recent proxy evidence and modeling studies suggested the initiation of a wet-dry monsoonal climate from the Cretaceous period (145 million years ago, Ma) to the early Miocene or late Oligocene epoch, ∼25-22 Ma. Capitalizing on an ensemble of paleoclimate simulations for the early Eocene (56-48 Ma), we show that the Asian wet season was considerably weaker and shorter than present in the absence of an elevated heat source like the Tibetan Plateau in the early Eocene. The deficient upper tropospheric meridional temperature gradient couldn’t drive the seasonal northward migration of the precipitation band over South Asia. Additionally, the weaker cross-equatorial moisture flow was mechanically blocked by the Gangdese mountain along the southern edge of Asia, leading to significantly dry conditions in South Asia. The enhanced atmospheric greenhouse gases were inadequate to strengthen the seasonal circulation and precipitation variability to the present level. We argue that an altered wet and dry seasonality over South Asia was not necessarily qualified as the Eocene ‘monsoon’.

In many regions considered for deep geological repositories (DGR) for nuclear waste, repeated glaciations could occur within the time frame relevant to their longterm post-closure safety (up to 1 million years; Myr). Ice sheets can affect the long-term safety of a DGR by elevating the hydrostatic pressure at DGR depth, altering groundwater flow and chemistry, influencing the frequency and severity of earthquakes, and causing surface bedrock erosion. Therefore, DGR safety assessments must account for uncertainties in future ice-sheet variability, including the timing, frequency and duration of ice sheets at the DGR site. Using coupled ice sheet-climate models to constrain uncertainties in icesheet variability over the next 1 Myr is not feasible due to the long timescales involved and substantial computational requirements. Instead, we propose a simplified methodology to assess future ice-sheet variability at potential DGR sites using reconstructions of past ice sheets and global simulations of future climate change. The simulations are conducted using a conceptual climate model driven by changes in insolation and atmospheric CO2 concentrations resulting from anthropogenic emissions. The model is calibrated with 500 000 years (500 kyr) of climate proxy data inferred from deep-ocean sediments. Applying this methodology to the planned Swedish DGR site intended for disposal of spent nuclear fuel in Forsmark suggests that the onset of the next glaciation at the site will not occur until 100 kyr after present, even in the absence of anthropogenic CO2 emissions. However, anthropogenic emissions have the potential to delay the next glaciation in Forsmark by several hundred thousand additional years. Following the initial glaciation, our results suggest that the frequency and duration of subsequent glaciations in Forsmark resemble those observed over the last 800 kyr. Considering uncertainties in anthropogenic emissions and future climate evolution, a wide range of possible future glacial developments is identified. At the extremes of this uncertainty range - developments with a low likelihood of occurrence but relevant for evaluating the robustness of the DGR - we find that Forsmark could experience ice-sheet coverage for nearly half of the next 1 Myr or remain almost entirely ice-free throughout this period. The proposed methodology is easy to implement and applicable to any potential DGR site with a recorded history of glaciations.

Understanding the potential drivers of spatial-temporal patterns in biodiversity has been a central tenet in biogeography and palaeontology for decades. More than 30 hypotheses have been proposed, including null models and theories based on environmental controls, energy, area, speciation/extinction dynamics, time, habitat features, ecological niches and biotic interactions. Yet, no consensus has been reached, and question remains whether a primary cause explains temporal trends and spatial patterns in biodiversity such as the latitudinal biodiversity gradient. Here we combine a macroecological model with global climate simulations to show that the niche-environment interaction may explain changes in global marine biodiversity and associated large-scale spatial patterns during the Phanerozoic (last 541 million years). We show that the niche-environment interaction imposed both a species carrying capacity and spatial constraints on marine biodiversity that defined the latitudinal biodiversity gradient. Although our model suggests that climate modulated the niche-environment interaction, hence spatial biodiversity patterns, it also demonstrates that palaeogeographical evolution imposed changes in shallow-water area, continental fragmentation and the location of landmasses relative to climatic belts and may have constituted the fundamental driver of changes in global marine biodiversity at the geological time scale. Therefore, several mechanisms interacted to balance the niche-environment interaction and drove the trajectory of marine biodiversity during the Phanerozoic.

The feedback between atmospheric CO2 concentrations and silicate weathering is one of the key controls on the long-term climate of the Earth. The potential silicate weathering flux (as a function of conditions such as temperature, runoff, and lithology), or “weatherability”, is strongly affected by continental configuration; thus the position of continental landmasses can have substantial impacts on CO2 drawdown rates. Here, we investigate the potential impact of palaeogeographical changes on steady-state CO2 concentrations during the Cretaceous–Eocene period (145–34 Ma) using a coupled global climate and biogeochemical model, GEOCLIM, with higher-resolution climate inputs from the HadCM3L general circulation model (GCM). We find that palaeogeographical changes strongly impact CO2 concentrations by determining the area of landmasses in humid zones and affecting the transport of moisture, that runoff is a strong control on weatherability, and that changes in weatherability could explain long-term trends in CO2 concentrations. As Pangaea broke up, evaporation from the ocean increased and improved moisture transport to the continental interiors, increasing runoff rates and weathering fluxes, resulting in lower steady-state CO2 concentrations. Into the Cenozoic, however, global weatherability appears to switch regimes. In the Cenozoic, weatherability appears to be determined by increases in tropical land area, allowing greater weathering in the tropics. Our modelled CO2 concentrations show some strong similarities with estimates derived from proxy sources. Crucially, we find that even relatively localised changes in weatherability can have global impacts, highlighting the importance of so-called weathering “hotspots” for global climate. Our work also highlights the importance of a relatively high-resolution and complexity-forcing GCM in order to capture these hotspots.

The Miocene (∼23–5 Ma) is a past warm epoch when global surface temperatures varied between ∼5 and 8°C warmer than today, and CO 2 concentration was ∼400–800 ppm. The narrowing/closing of the tropical ocean gateways and widening of high‐latitude gateways throughout the Miocene is likely responsible for the evolution of the ocean's overturning circulation to its modern structure, though the mechanisms remain unclear. Here, we investigate early and middle Miocene ocean circulation in an opportunistic climate model intercomparison (MioMIP1), using 14 simulations with different paleogeography, CO 2 , and vegetation. The strength of the Southern Ocean‐driven Meridional Overturning Circulation (SOMOC) bottom cell is similar in the Miocene and Pre‐Industrial (PI) but dominates the Miocene global MOC due to weaker Northern Hemisphere overturning. The Miocene Atlantic MOC (AMOC) is weaker than PI in all the simulations (by 2–21 Sv), possibly due to its connection with an Arctic that is considerably fresher than today. Deep overturning in the North Pacific (PMOC) is present in three simulations (∼5–10 Sv), of which two have a weaker AMOC, and one has a stronger AMOC (compared to its PMOC). Surface freshwater fluxes control northern overturning such that the basin with the least freshwater gain has stronger overturning. While the orography, which impacts runoff direction (Pacific vs. Atlantic), has an inconsistent impact on northern overturning across simulations, overall, features associated with the early Miocene—such as a lower Tibetan Plateau, the Rocky Mountains, and a deeper Panama Seaway—seem to favor PMOC over AMOC.

A tuned version of HadCM3 (HadCM3t) is used to simulate the climate of the mid‐Pliocene warm period (mPWP) and is compared with the original untuned version of HadCM3 (HadCM3u). After the tuning, HadCM3t performs as well as HadCM3u in simulating the preindustrial climate, but aligns better with the reconstructed mPWP sea surface temperature anomalies, primarily due to a better representation of high latitude warming. Regarding the mPWP climate anomaly relative to the preindustrial, compared to HadCM3u, HadCM3t produces stronger mid‐to‐high latitude warming with polar warming 2.2 times the global mean, which is higher than the 2.0 of HadCM3u. The warming of the mPWP is primarily explained by an increase in emissivity and surface albedo. The warming of the polar regions induced by emissivity and surface albedo from HadCM3t is higher by 0.6C and 0.7C respectively, than that from HadCM3u, leading to warmer mPWP high latitudes. The increase in shortwave radiation over the Polar Regions is driven mainly by changes in surface albedo, which lead to a temperature rise of +0.7C, and by changes in cloud cover, which contribute an additional +0.1C to the temperature increase. Here, the increased cloud‐induced shortwave radiation change is due to decreased cloud fraction and decreased cloud scattering effect; the increased surface albedo‐induced radiative effects result from the increased ice loss due to warm high latitudes. This tuning allows models like HadCM3 to better align with proxy data, offering a more reliable baseline for projecting future scenarios under similar conditions.

Cambrian palynomorphs include conventional acritarchs (organic-walled microfossils of unknown affinity, often interpretable as phytoplankton cysts) but also spine-shaped forms sometimes interpreted as animal body parts. Here, we examine new specimens of the problematic spine-shaped palynomorph Corollasphaeridium Martin and reassess its taxonomic composition and biological affinities. The type species C. wilcoxianum, known previously from Cambrian-Ordovician boundary intervals in western Canada and north China, is reported here from the Nolichucky Shale Formation of the USA and the Deadwood Formation of Canada and the USA, extending its biostratigraphical range back to the lower upper Cambrian (Furongian) or middle Cambrian (Miaolingian). The new specimens of C. wilcoxianum exhibit the diagnostic form of a trumpet-shaped conical body with 5-12 apical spines, a flaring and infolded aperture rim, and an ornamentation of branched ridges. In contrast, specimens from the lower Cambrian (Series 2, Stage 4) Forteau Formation of Canada are assigned to C. lissum sp. nov. In common with lower Cambrian species from Australia and Siberia, C. lissum lacks the ridged ornamentation of the type species, but shares a distinctive infolded aperture rim and is intermediate in shape, supporting the reunification of all species under Corollasphaeridium. The morphology and size distribution of Corollasphaeridium are difficult to reconcile with a phytoplanktic cyst or animal identity and instead support comparisons with the protective cases of protists such as amoebozoan tests and tintinnid ciliate loricae. Therefore, we interpret Corollasphaeridium as a loricate protist, albeit without clear synapomorphies with any extant group. The palaeoenvironmental and palaeogeographical distribution of Corollasphaeridium suggests localisation in near-shore habitats, possibly limited to warm-water environments (palaeo-tropics to subtropics). Our results further emphasise the hidden high-level taxonomic diversity among 'acritarchs'.

Spatial incompleteness in the fossil record severely diminishes the observed ecological and geographic ranges of clades. The biological processes shaping species distributions and richness through time, however, also operate across geographic space and so clade biogeographic histories can indicate where their lineages must have successfully dispersed through these sampling gaps. Consequently, these histories are powerful, yet untapped tools for quantifying their unobserved ecographic diversity. Here, we couple phylogeographic modelling with a landscape connectivity approach to reconstruct the origins and dispersal of Permian-Triassic archosauromorph reptiles. We recover substantial ecographic diversity from the gaps in their fossil record, illuminating the cryptic first 20 million years of their evolutionary history, a peak in climatic disparity in the earliest Triassic period, and dispersals through the Pangaean tropical dead zone which contradict its perception as a hard barrier to vertebrate movement. This remarkable tolerance of climatic adversity was probably integral to their later evolutionary success.

Planamandibulus nevadensis n. gen n. sp. is a newly discovered exceptionally preserved Laurentian phosphatocopid crustacean described from the upper Windfall Formation (Furongian, Stage 10) in Nevada. Planamandibulus nevadensis has closest affinity with the Baltic and Avalonian taxon Cyclotron. Its occurrence in sedimentary facies associated with dysoxia on the Laurentian paleocontinent fills in a gap in the global distribution of phosphatocopid crustaceans, facilitating a paleoenvironmental synthesis of this Cambrian group. We assess 75 taxa from nine paleocontinental areas spanning Cambrian stages 3 to 10 (similar to 521-486.9 Ma). Comparison of these data with paleoclimate model simulations suggests that phosphatocopid distribution is explained partly by biogeography and ocean temperature patterns. Dabashanella species (e.g., D. hemicyclica Huo et al., 1983) are found across the low paleolatitude (<35 degrees) paleocontinents of East Gondwanan (Australia), South China, and the central Asian terranes, spanning marine shelf carbonates to deeper marine black shale lithofacies, but are absent from mid- and high-paleolatitude sites, suggesting a warmer water preference. A similar warm-water preference is inferred for endemic taxa (e.g., Ulopsis, Parashergoldopsis) of East Gondwana, and perhaps for the newly described Laurentian Planamandibulus. By contrast, the mid- to high-paleolatitude paleocontinents Baltica and Avalonia are characterized by Veldotron, Cyclotron, Bidimorpha, Waldoria, Vestrogothia, Falites, and Trapezilites species, which occur in deep-shelf, cooler-water settings, typically below storm wave base. Hesslandona species sensu lato occur in mid-depth (likely above storm-wave base) warm tropical marine waters but are more typically found in deeper shelf and cooler waters in mid to high paleolatitudes. Phosphatocopids are also associated with sedimentary deposits characteristic of low environmental oxygen concentrations; this is emphasized by a peak in occurrences in the Guzhangian (Miaolingian) and Paibian (Furongian) stages, around the interval of the Steptoean Positive Carbon Isotope Excursion (SPICE) and its associated expansion of anoxic water masses onto shallow marine shelves. Our data compilation and data-model comparison support the environmental preference of phosphatocopids for low-oxygen, but not anoxic, water masses, and the new occurrence of Planamandibulus is consistent with this pattern.

The origin of pterosaurs, the first vertebrates to achieve powered flight, is poorly understood, owing to the temporal and morphological gaps that separate them from their closest non-flying relatives, the lagerpetids. Although both groups coexisted during the Late Triassic, their limited sympatry is currently unexplained, indicating that ecological partitioning, potentially linked to palaeoclimate, influenced their early evolution. Here we analysed pterosauromorph (pterosaur + lagerpetid) palaeobiogeography using phylogeny-based probabilistic methods and integrating fossil occurrences with palaeoclimate data. Our results reveal distinct climatic preferences and dispersal histories: lagerpetids tolerated a broader range of conditions, including arid belts, enabling a widespread distribution from the Middle to early Late Triassic. Conversely, pterosaurs preferred wetter environments, resulting in a patchier geographical distribution that expanded only as humidity increased in the Late Triassic, probably following the Carnian Pluvial Event. This major environmental disturbance, potentially driven by changes in CO2-related thermal constraints and/or palaeogeography, appears to have had a key role in shaping early pterosauromorph evolution by promoting spatial segregation and distinct climatic niche occupation.