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Here we present a new global compilation of modern pollen and spore data for use in testing and evaluating palaeoclimate reconstruction methods. The resulting dataset contains 21,503 pollen assemblages from all continents excluding Antarctica. All pollen assemblages have geographical coordinates listed, and the majority have an elevation measurement. Taxonomic nomenclature has been standardised. 

Hydrologic reconstructions from North America are largely unknown for the Middle Miocene. Examination of fungal palynomorph assemblages coupled with traditional plant-based palynology permits delineation of local, as opposed to regional, climate signals and provides a baseline for study of ancient fungas. Here, the Fungi in a Warmer World project presents paleoecology and paleoclimatology of 351 fungal morphotypes from 3 sites in the United States: the Clarkia Konservat-Lagerstätte site (Idaho), the Alum Bluff site (Florida), and the Bouie River site (Mississippi). Of these, 83 fungi are identified as extant taxa and 41 are newly reported from the Miocene. Combining new plant-based paleoclimatic reconstructions with funga-based paleoclimate reconstructions, we demonstrate cooling and hydrologic changes from the Miocene climate optimum to the Serravallian. In the southeastern United States, this is comparable to that reconstructed with pollen and paleobotany alone. In the northwestern United States, cooling is greater than indicated by other reconstructions and hydrology shifts seasonally, from no dry season to a dry summer season. Our results demonstrate the utility of fossil fungi as paleoecologic and paleoclimatic proxies and that warmer than modern geological time intervals do not match the “wet gets wetter, dry gets drier” paradigm. Instead, both plants and fungi show an invigorated hydrological cycle across mid-latitude North America. 

Summary MyCeno (Mycology of the Cenozoic) 1.0 contains 4,209 records of fossil fungi from the Cenozoic era (66 million years ago to present), from around the world. This dataset consists of records of palynomorphs (spores, and other microscopic fossils), as well as fungal macrofossils. Every record in the dataset comes with information about the fossil's location, estimated age range, and geology. This includes latitude and longitude coordinates, names or descriptions of the fungal fossil found, the technique used for dating the fossil, a grade given for the level of dating uncertainty, as well as full citations for the primary source and any supporting literature for every record. Additionally, 90% of records have a recorded sediment type, 72% have geological formation/member/bed names, and 83% have a DOI or hyperlink to the primary source. 86% of records have a current valid scientific name attributed to the fossil, with name authors and synonyms listed. For these records, the higher classification (i.e. the closest higher taxonomic classification that the identified fungus belongs to, from family-level upwards) is also recorded, as well as whether or not the genus is extant.  Nearest living relatives have been identified for 20% of records. Fossil ages in the dataset concentrate around the Miocene, but cover different epochs across the Cenozoic.   Usage & Applications This dataset was designed to be easy to use. Each variable has its own column, and the table is uploaded as a comma-separated values (CSV) file so that it can be opened using various programmes (flexible for different user preferences). For example, it can be opened in Microsoft Excel, or can be viewed and manipulated using code such as in RStudio. This dataset will prove valuable to people interested in studying ancient fungal diversity, understanding the evolution of fungi, or reconstructing palaeoecology, palaeoenvironments or palaeoclimates. 

Globally, the middle Cenozoic (Oligocene to early Miocene, ~33.9–15.97 Ma) was characterized by a warmer, wetter climate than present. Reconstructing the climate of this stratigraphic interval helps us to better understand the implications of present and future anthropogenically-driven climate change in an Earth system with an established Antarctic ice mass and comparable pCO2 levels (400–700 ppm). Relative to mainland Europe, little palaeoclimate work has been done on the British Isles for this time interval. Compiled middle Cenozoic palynology records from across the British Isles were used to quantitatively reconstruct palaeoclimate, which was then used to define Köppen-Geiger signatures for each palynomorph assemblage. These reconstructions were used to show the presence of a temperate, dry-winter and hot-summer (Cwa) Köppen-Geiger climate type before 31.8 Ma, which was possibly a short-lived event driven by precessional (~26 k.y.) forcing. We attribute reconstructions with dry-winter Köppen-Geiger classifications to combined eccentricity-obliquity-precession (~405 k.y.) forcing, after the Eocene-Oligocene Transition. Declines in Mean Annual Temperature, in Chattian sections, are associated with the Svalbardella-2 and 3 North Sea cooling events. The late Oligocene warming event is shown to have produced tropical rainforest (Af) Köppen-Geiger classification types in the British Isles. Following early Miocene glaciation, a temperate, no-dry-season, warm-summer (Cfb) signature was reconstructed. We suggest the present-day climate of the northwest margin of Europe is comparable to the early Miocene palaeoclimate. Under increased pCO2 concentrations, based on projected twenty-first century anthropogenic warming scenarios, there is potential for wetter summers becoming more prevalent within the next century. 

Abstract. Deep-time palynological studies are necessary to evaluate plant and fungal distribution under warmer-than-present scenarios such as those of the Middle Miocene. Previous palynological studies from southern McMurdo Sound, Antarctica (SMS), have provided unique documentation for Neogene environments in the Ross Sea region during a time of pronounced global warming. The present study builds on these studies and provides a new climate reconstruction using the previously published SMS pollen and plant spore data. Additionally, 44 SMS samples were reanalyzed with a focus on the fungal fraction of the section to evaluate the fungal distribution under warmer than present conditions. The probability-based climate reconstruction technique (CREST) was applied to provide a new plant-based representation of regional paleoclimate for this Miocene Climatic Optimum (MCO) locality. CREST reconstructs a paleoclimate that is warmer and significantly wetter than present in SMS during the MCO, with mean annual precipitation reconstructed at 1147 mm yr−1 (95 % confidence range: 238–2611 mm yr−1) and a maximum mean annual temperature of 10.3 ∘C (95 % confidence range: 2.0–20.2 ∘C) for the warmest intervals of the MCO. The CREST reconstruction fits within the Cfb Köppen–Geiger climate class during the MCO of SMS. This new reconstruction agrees with previous reconstructions using various geochemical proxies. The fungal palynological analyses yielded surprising results, with only a single morphotype recovered, in low abundance, with concentrations ranging up to 199 fungi per gram of dried sediment. The taxa present belongs to the Apiosporaceae family and are known to be adapted to a wide range of climate and environmental conditions. As fungi are depauperate members of the SMS MCO palynofloras and because the one morphotype recovered is cosmopolitan, using the fungi record to confirm a narrow Köppen–Geiger climate class is impossible. Overall, the study demonstrates refinement of plant-based paleoclimatic reconstructions and sheds light on the limited presence of fungi during the MCO in Antarctica. 

Fossil fungi from periods warmer than modern climates provide unique insights into the future impacts of anthropogenic climate change. Here we report the fossil fungal assemblage from the late Middle Miocene Kenslow Member of central England, associated with climatic conditions warmer than the present-day. The identification of 110 morphotypes, which primarily relate to moist environments and the presence of wood, have been used to develop a new nearest living relative palaeoclimate reconstruction. The fungal assemblage indicates a Köppen–Geiger climate class, represented by temperate conditions, no dry season, and warm summers. This new fungal-based palaeoclimate reconstruction technique holds exciting potential to explore critically important but poorly understood palaeoenvironments, and the resulting qualitative inferences align well with previously published palaeobotanical quantitative estimates of palaeoclimate. These findings show that diverse fungal assemblages can successfully be used to reconstruct past climates for the first time. 

The middle Miocene Climate Optimum (MMCO) was the warmest interval of the last 23 million years and is one of the best analogs for proposed future climate change scenarios. Fungi play a key role in the terrestrial carbon cycle as dominant decomposers of plant debris, and through their interactions with plants and other organisms as symbionts, parasites, and endobionts. Thus, their study in the fossil record, especially during the MMCO, is essential to better understand biodiversity changes and terrestrial carbon cycle dynamics in past analogous environments, as well as to model future ecological and climatic scenarios. The fossil record also offers a unique long-term, large-scale dataset to evaluate fungal assemblage dynamics across long temporal and spatial scales, providing a better understanding of how ecological factors influenced assemblage development through time. In this study, we assessed the fungal diversity and community composition recorded in two geological sections from the middle Miocene from the coal mines of Thailand and Slovakia. We used presence-absence data to quantify the fungal diversity of each locality. Spores and other fungal remains were identified to modern taxa whenever possible; laboratory codes and fossil names were used when this correlation was not possible. This study represents the first of its kind for Thailand, and it expands existing work from Slovakia. Our results indicate a total of 281 morphotaxa. This work will allow us to use modern ecological data to make inferences about ecosystem characteristics and community dynamics for the studied regions. It opens new horizons for the study of past fungal diversity based on modern fungal ecological analyses. It also sheds light on how global variations in fungal species richness and community composition were affected by different climatic conditions and under rapid increases of temperature in the past to make inferences for the near climatic future.