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Unlabelled: •, Premise of the Study: The early Cenozoic was a key period of evolutionary radiation in Fagaceae. The common notion is that species thriving in the modern summer-dry climate of California originated in climates with ample summer rain during the Paleogene.•, Methods: We investigated in situ and dispersed pollen of Fagaceae from the uppermost Eocene Florissant fossil beds, Colorado, United States, using a combined light and scanning electron microscopy approach.•, Key Results: Pollen types of Castaneoideae with affinities to modern Castanea, Lithocarpus, and Castanopsis were recognized. Pollen of the extinct genus Fagopsis represents a derived type of Castaneoideae pollen. Infrageneric groups of Quercus were well represented, including pollen of Group Protobalanus. The taxonomic diversity of Fagaceae and of the total plant assemblage indicates a mosaic of microclimates, that range from pronounced to weakly seasonal climates and depend on slope aspect and elevation. Continental climatic conditions may have triggered the evolution of sclerophyllous leaves and adaptive radiation in Quercus and other taxa thriving today under distinctly summer-dry and winter-dry climates.•, Conclusions: Vegetation types similar to modern vegetation belts of the Coastal Ranges (chaparral, nemoral conifer forest) were established in the Front Range in the late Eocene. Coeval plant assemblages from the Coastal Ranges of California indicate distinctly subtropical, moist climates. Hence, characteristic elements found today in the summer-dry and winter-dry climates of Pacific North America (Quercus Group Protobalanus, Notholithocarpus) may opportunistically have dispersed into their modern ranges later in the Cenozoic. This scenario is in contrast to the evolution and migration patterns of their western Eurasian Mediterranean counterparts (Quercus Group Ilex)., (© 2014 Botanical Society of America, Inc.)

Middle Eocene interbasaltic deposits of Hareø, West Greenland, have yielded a rich leaf and fruit record, which was described in the second half of the nineteenth century. In this study, we describe dispersed spores and pollen from the Aumarûtigssâ Member of the Hareøen Formation in order to obtain a more comprehensive picture of the late middle Eocene vegetation of West Greenland. The spore/pollen assemblage, derived from a resinite-rich coal bed, comprises 123 taxa, of which 14 belong to mosses, ferns and fern-allies, 14 to gymnosperms, and 95 to angiosperms. The most diverse groups of angiosperms are Fagales, comprising 27 taxa, and Rosales, represented by nine taxa. Along with conifers belonging to Pinaceae, these groups reflect the temperate character of the Hareø flora. In addition, a few 'exotic' elements include cycads probably belonging to an extinct temperate lineage that was widespread across the Northern Hemisphere during the Paleogene, palm trees, members of Mastixioideae and Santalaceae, both of which were characteristic elements of more southern warm temperate floras of Europe. A detailed comparison with macrofossil and spore/pollen assemblages of roughly coeval sites from Axel Heiberg Island (Canada), Spitsbergen (Arctic Ocean), and ODP site 151-913B in the Norwegian-Greenland Sea, show a highly consistent picture of the vegetation during this time. [ABSTRACT FROM AUTHOR]

The Late Oligocene to Early Miocene flora of the Ban Pa Kha Subbasin (Li Basin, northern Thailand) provides a record of montane dry tropical oak-pine forests. The rich ensemble of Fagaceae typical of these forests might have existed in the wider region of Southeast Asia since Eocene times and various fossil plant assemblages represented both lowland (Fagaceae, Dipterocarpaceae) and upland (Fagaceae, Pinaceae) tropical forests. These findings are in conflict with previous interpretations of vegetation development in northern Thailand, which stressed that stratigraphically older (possibly Late Oligocene) spore and pollen assemblages in northern Thailand were markedly different from the modern tropical flora and had a distinct northern temperate character. A major change in climate would have caused a dramatic shift to tropical conditions since the Mid-Miocene. Considering palaeobotanical data from adjacent regions in Southeast Asia, we suggest that differences in spore and pollen assemblages in intermontane basins in northern Thailand are more likely to represent different facies and lowland/upland settings. Assembly of these forest ecosystems, typically comprising Quercus sections Cyclobalanopsis , Ilex and Quercus , pollen of Castaneoideae with affinities to Castanopsis and Lithocarpus , and extinct fagaceous genera such as Eotrigonobalanus , most probably dates back to the Eocene. The absence of oaks of Quercus section Cerris in the spore and pollen assemblage of the Ban Pa Kha Subbasin, despite this group being part of the modern vegetation, might reflect the late arrival (secondary radiation) of this chiefly temperate group in tropical Southeast Asia. [ABSTRACT FROM AUTHOR]

Late Oligocene leaf assemblages from four sites in Southwestern Siberia (Kurgan, Tyumen, Omsk oblasts) are described. Twenty-three leaf taxa and 3 reproductive structures represent local vegetation of a lake (Salvinia, Typha, Phragmites, Nelumbo, Hemitrapa, Liquidambar, Pterocarya, Alnus, Populus, Salix, Nyssa). Additionally, 57 spore and pollen taxa were recorded from one site (Shish River). Gymnosperms dominate the assemblage with ~30% Pinaceae and ~25% taxodiaceous (papillate) Cupressaceae pollen. Ferns and peat mosses (Sphagnaceae) comprised ~6%. Angiosperms were dominated by Fagaceae, Betulaceae, Juglandaceae and Ulmus and comprised a few exotic elements (Liquidambar, Eucommia, Nyssa, Symplocos); scarce herbaceous plants reflect lakeshore vegetation. The flora of the Turgay type comprised old elements (Nelumbo protospeciosa, Liquidambar europaea, taxodiaceous/papillate Cupressaceae, Quercus sect. Protobalanus) and taxa present in Siberia/Kazakhstan during the Paleogene with later arrivals in Europe (Ulmus pyramidalis, Quercus pseudocastanea, Alnus julianiformis, Byttneriophyllum tiliifolium). A few taxa were endemic in the late Oligocene of western Siberia (Trapa praeconocarpa, Platycrater iljinskajae sp. nov.). Combined macrofossil and palynological evidence places the Shish River site flora into the late Oligocene Zhuravka (Turtas) Formation. Floras of similar composition from western Eurasia are commonly middle Miocene or younger in age highlighting the dynamic spatiotemporal evolution of temperate Eurasian floras during the Cenozoic. [ABSTRACT FROM AUTHOR]

Premise: The Fagaceae comprise around 1000 tree species in the Northern Hemisphere. Despite an extensive fossil pollen record, reconstructing biogeographic patterns is hampered because it is difficult to achieve good taxonomic resolution with light microscopy alone. We investigate dispersed pollen of Fagaceae from the Miocene Søby flora, Denmark. We explore the latitudinal gradient in Fagaceae distribution during the Miocene Climatic Optimum (MCO) in Europe and the Northern Hemisphere to compare it with the Eocene Warmhouse and the present. Methods: We investigated dispersed pollen using light and scanning electron microscopy. We assessed biogeographic patterns in Fagaceae during two warm periods in Earth history (MCO, Eocene) and the present. Results: Eight species of Fagaceae were recognized in the Søby flora. Of these, Fagus had a continuous Mediterranean to subarctic distribution during MCO; Quercus sect. Cerris and castaneoids had northern limits in Denmark, and evergreen Quercus sect. Ilex in Central Europe. In a northern hemispheric context, Fagus and sections of Quercus had more northerly distribution limits during Eocene and MCO with maximum northward extensions during Eocene (Fagus, castaneoids) or Oligo‐Miocene (Quercus sects. Cerris and Ilex). The known distribution of the extinct Tricolporopollenites theacoides during MCO included Central Europe and East China, while this taxon thrived in South China during Eocene. Conclusions: More northerly distributions during MCO and Eocene probably were determined by temperature. In contrast, fossil occurrences in areas that are arid or semi‐humid today were determined by maritime conditions in these areas (western North America, Central Asia) during the Cenozoic. [ABSTRACT FROM AUTHOR]

Diospyros is a large genus of woody flowering plants with a predominantly subtropical and tropical modern distribution. Fossils attributed to Diospyros are mainly leaf impressions from Cretaceous and Cenozoic strata across the Northern Hemisphere. However, it is difficult to assign such fossils to Diospyros because genus-diagnostic leaf characteristics remain to be identified. Unequivocal fossil records of Diospyros are few, including staminate flowers with in situ pollen from the late Eocene of South Australia and dispersed pollen from Cenozoic strata in the Northern Hemisphere. Here, we investigated dispersed pollen and calyx remains from Miocene deposits of Denmark using a combined scanning electron/light microscopy approach. Tricolporate, relatively large pollen with lalongate pori and long bow-shaped colpi and a distinctive micro/nanorugulate exine ornamentation together with persistent 4-lobed flower calyces allow unambiguous identification of the genus. Based on the large size of the calyx, we describe a new fossil-species of Diospyros. Further, a review of the fossil pollen record of Diospyros shows that, in addition to the Australian record, the genus was present in South China, western North America and Europe during the Eocene and in East and South Africa and Central Asia during the Oligo-Miocene. Although still scanty, the pollen record can contribute vital information for time-calibrated molecular phylogenies to resolve conflicting biogeographic inferences. A thorough description of the historical biogeography of Diospyros is still in its infancy. While we initiate such a study here, development of a comprehensive picture will require further studies of dispersed pollen grains with high taxonomic resolution. [ABSTRACT FROM AUTHOR]

The piggyback basin of Bezhan, southeastern Albania, was formed during the late Neogene and contains Pliocene/Pleistocene deposits. These continental deposits consist of marls, siltstones and clays separated by a thin series of lignite-seams alternating with clays (Bezhan formation). We investigated leaf fossils and dispersed pollen from marls of the upper portion of this formation. Fifty-two plant taxa comprising algae, gymnosperms, and angiosperms were recovered. Of these, at least 19% belong to extant species and less than 16% belong to taxa today extinct in western Eurasia. Tsuga is represented by three pollen taxa with affinities to modern Chinese, Japanese, and North American species. Herbaceous taxa indicative of steppe (Artemisia, Amaranthaceae) occur in low quantities (≤1%) suggesting an interglacial setting. Four vegetation units are recognised: Wet riparian and aquatic vegetation, mesic oak forest, dry sub-Mediterranean woodland, and montane conifer forest. A comparison of the Bezhan flora with well-dated Pliocene and Pleistocene floras of Italy suggests a Calabrian (late early Pleistocene) age for the upper unit. This estimate is based on the abundance of extant taxa, the absence of subtropical taxa, and threshold values of particular taxa (Tsuga, Carya). The findings are in agreement with age estimates for extant tree species from molecular studies. [ABSTRACT FROM AUTHOR]

Eocene Baltic amber forms the largest amber deposit worldwide; however, its source vegetation and climate are much debated. Representatives of the oak family (Fagaceae) were abundant in the Baltic amber source area based on numerous inclusions of staminate inflorescences or individual florets, previously assigned to Castanea and Quercus. However, the actual generic and infrageneric diversity of Fagaceae from Baltic amber remained unknown. Using flower characteristics and section-diagnostic in situ pollen of staminate inflorescences and detached floret inclusions, we describe 18 fossil-species of Fagaceae making this family by far the most diverse plant family preserved in Baltic amber. We substantiate the occurrence of the Castaneoideae, Quercoideae (Quercus sect. Cyclobalanopsis/Lobatae; Q. sect. Lobatae; Q. sect. Protobalanus), Trigonobalanoideae and the extinct genus Eotrigonobalanus. Among the 18 fossil-species, six are described as new: Q. aimeeana, Q. casparyi, Q. multipilosa, E. campanulata, E. conwentzii, E. longianthera; and one new combination is published: Q. brachyandra (≡ Castanea brachyandra). In addition, a lectotype is designated for the name Quercites meyerianus and neotypes are designated for the names Castanea inclusa and Quercus longistaminea (≡ C. longistaminea). Members of the Fagaceae probably inhabited azonal and zonal vegetation types of the amber source area, including bottomland flood-plains and stream banks (Q. sect. Lobatae), dry habitats (Q. sect. Lobatae, Q. sect. Protobalanus), peaty soils, riparian and swamp forests (Castanopsis, Eotrigonobalanus), as well as mixed mesophytic forests (castaneoids, Quercoideae, trigonobalanoids). Affinities to extant North American and E to SE Asian floras support the recent notion that late Eocene Baltic amber (38–34 Ma) was formed in a warm-temperate climate. Citation: Sadowski E.-M., Schmidt A. R. & Denk T. 2020: Staminate inflorescences with in situ pollen from Eocene Baltic amber reveal high diversity in Fagaceae (oak family). – Willdenowia 50: 405–517. doi: https://doi.org/10.3372/wi.50.50303 Version of record first published online on 1 December 2020 ahead of inclusion in December 2020 issue. [ABSTRACT FROM AUTHOR]

The former family Taxodiaceae is currently treated as nine genera in five subfamilies of the family Cupressaceae. Pollen of the 'taxodiaceous' Cupressaceae typically has a papilla in the leptoma area and is common in Cenozoic strata because some of its genera were key elements in lignite forming swamp forests. Dispersed fossil pollen of this group are often assigned to particular genera and, based on the modern ecologies of these taxa, to particular palaeoenvironments. In this study, we investigated pollen of all nine genera of the former Taxodiaceae using light and scanning electron microscopy to evaluate whether pollen morphology can be used to discriminate modern genera of this paraphyletic group. We found few genus- or subfamily-diagnostic characters among members of taxodiaceous Cupressaceae. Features such as orbiculae and pollen and leptoma size cannot be used to discriminate subfamilies. However, three basal subfamilies share short papillae, whereas in two more derived clades (Sequoioideae and Taxodioideae) papillae are markedly longer. In the generally non-papillate core Cupressaceae, the leptoma (aperture) area may or may not possess a distinct circular thinning as also found in the basal grade of taxodiaceous Cupressaceae. Our results show that it is difficult if not impossible to distinguish genera of the ecologically distinct Taxodioideae and Sequoioideae based on pollen morphology. In view of a much wider ecological amplitude of many taxodiaceous Cupressaceae during large parts of the Cenozoic, we conclude that it is not recommendable to infer particular palaeoenvironments on the basis of dispersed taxodiaceous pollen grains alone. [ABSTRACT FROM AUTHOR]

The early Miocene was a period of major palaeogeographic reorganization in the eastern Mediterranean region, during which time the Anatolian Plateau became subaerial and several intracontinental basins intermittently became connected to the Paratethys and Mediterranean seas. In this paper, we analyse early Miocene vegetation and climate using leaf records, palynological assemblages, and fossil wood at 36 localities from western and central Turkey, most of which have precise age control based on radiometric dating and mammal faunal ages. Using the leaf flora of Güvem (Beş Konak, Keseköy), Climate Leaf-Analysis Multivariate Program (CLAMP) analyses and Köppen signatures were employed to infer a palaeoclimate typical of modern laurel forest regions. Based on the palynological records, abundance of various pollen-taxa was used as a measure of openness of vegetation and regional presence of major tree taxa. Most pollen floras are dominated by tree pollen (ranging from 85 to 98%) and indicated widespread afforestation. In the pollen diagrams, shifts in dominance from swamp forest elements (Taxodioideae) to well-drained forests (Pinaceae) indicate changes in lake levels or phases of basin development. Such shifts may have been associated with the development of more xeric forest vegetation. Wood anatomical features such as false tree rings further may indicate seasonal climate. Pollen diagrams and macrofossils reflect zonal and azonal broadleaf and needleleaf forest and extrazonal open vegetation. The latter occurred in areas with shallow soils on volcanic rocks or limestone (e.g. cycads, Dracaena), or coastal areas (herb dominance). Taxonomic composition and biogeographic affinities suggest laurel forest as a major forest biome on well-drained soils and ecotones between laurel forest and broadleaf deciduous forest biomes. A comparison with younger floras shows that these are neither more diverse nor more warmth-loving despite an increase in global temperature (Mid-Miocene Climatic Optimum) suggesting bottlenecks during previous (Oligocene) cooler times for warmth-loving taxa. • 36 floras are used to infer biomes and climate during the early Miocene of Turkey. • Dominating plant groups belong to evergreen Fagales and Coniferales. • Herbs are rare except for in coastal areas and extrazonal areas. • Laurel Forest Biome is a major forest biome in the early Miocene of Turkey. • Arboreal Pollen/Non-Arboreal Pollen ratios range between 98% and 85%. [ABSTRACT FROM AUTHOR]

Modern lineages of the beech family, Fagaceae, one of the most important north-temperate families of woody flowering plants, have been traced back to the early Eocene. In contrast, molecular differentiation patterns indicate that the Fagus lineage, Fagoideae, with a single modern genus, evolved much earlier than the remaining lineages within Fagaceae (Trigonobalanoideae, Castaneoideae, Quercoideae). The minimum age for this primary split in the Fagaceae has been estimated as 80 ± 20 Ma (i.e. Late Cretaceous) in recently published, time-calibrated phylogenetic trees including all Fagales. Here, we report fagaceous fossils from the Campanian of Wyoming (82-81 Ma; Eagle Formation [Fm]), the Danian of western Greenland (64-62 Ma; Agatdal Fm), and the middle Eocene of British Columbia (ca 48 Ma; Princeton Chert), and compare them to the Fagaceae diversity of the recently studied middle Eocene Hareøen Fm of western Greenland (42-40 Ma). The studied assemblages confirm that the Fagus lineage (= Fagoideae) and the remainder of modern Fagaceae were diverged by the middle Late Cretaceous, together with the extinct Fagaceae lineage(s) of Eotrigonobalanus and the newly recognised genus Paraquercus, a unique pollen morph with similarities to both Eotrigonobalanus and Quercus. The new records push back the origin of (modern) Fagus by 10 Ma and that of the earliest Fagoideae by 30 Ma. The earliest Fagoideae pollen from the Campanian of North America differs from its single modern genus Fagus by its markedly thicker pollen wall, a feature also seen in fossil and extant Castaneoideae. This suggests that a thick type 1 foot layer is also the plesiomorphic feature in Fagoideae although not seen in any of its living representatives. The Danian Fagus pollen of Greenland differs in size from those of modern species but is highly similar to that of the western North American early Eocene F. langevinii, the oldest known beech so far. Together with the Quercus pollen record, absent in the Campanian and Danian formations but represented by several types by the middle Eocene, this confirms recent dating estimates focussing on the genera Fagus and Quercus, while rejecting estimates from all-Fagales-dated trees as too young. The basic Castaneoideae pollen type, still found in species of all five extant genera of this putatively paraphyletic subfamily, represents the ancestral pollen type of most (modern) Fagaceae (Trigonobalanoideae, Castaneoideae, Quercoideae). [ABSTRACT FROM AUTHOR]

In this paper we document Fagaceae pollen from the Eocene of western Greenland. The pollen record suggests a remarkable diversity of the family in the early Cenozoic of Greenland. Extinct Fagaceae pollen types include Eotrigonobalanus, which extends at least back to the Paleocene, and two ancestral pollen types with affinities to the Eurasian Quercus Group Ilex and the western North American Quercus Group Protobalanus. In addition, modern lineages of Fagaceae are unambiguously represented by pollen of Fagus, Quercus Group Lobatae/Quercus, and three Castaneoideae pollen types. These findings corroborate earlier findings from Axel Heiberg Island that Fagaceae were a dominant element at high latitudes during the early Cenozoic. Comparison with coeval or older mid-latitude records of modern lineages of Fagaceae shows that modern lineages found in western Greenland and Axel Heiberg likely originated at lower latitudes. Further examples comprise (possibly) Acer, Aesculus, Alnus, Ulmus, and others. Thus, before fossils belonging to modern northern temperate lineages will have been recovered from older (early Eocene, Paleocene) strata from high latitudes, Engler's hypothesis of an Arctic origin of the modern temperate woody flora of Eurasia, termed 'Arcto-Tertiary Element', and later modification by R. W. Chaney and H. D. Mai ('Arcto-Tertiary Geoflora') needs to be modified. [ABSTRACT FROM AUTHOR]

Abstract: Foliage and reproductive structures of Platanaceae from the Upper Cretaceous (Santonian) of Quedlinburg, Central Germany, were comparatively studied and their systematic affinities established. One type of foliage preserved in sandstone and rarely in clayish siltstone belongs to the extinct genus Credneria. The leaves are typically obovate with a pinnate-actinodromous venation and distinct suprabasal veins. In addition, a substantial number of leaves preserved in siltstone and rarely in sandstone are identical to modern Platanus based on leaf architecture and epidermal features. As in modern Platanus leaf margin and size were found to be of no systematic significance in both fossil leaf types. Further, staminate flower heads preserved as cleavage compressions in siltstone were found in association with Platanus leaves; they contain pollen that is identical to modern Platanus in size and type of tectum. In addition, a few three-dimensionally preserved staminate flower heads with ca. 50 flowers on a receptaculum are described. Each flower appears to have a two-whorled perianth and six or seven stamens. The organs of the outer perianth whorl show a distinct epidermal cell pattern different from the inner ones. All perianth organs have the same length as the stamens. Stamens are bithecate and contain pollen identical to that found in compression fossils. Pistillate heads preserved in siltstone consist of numerous achenes with persistent styles, which show close similarity to modern Platanus. It remains unclear, whether additional inflorescence heads of uncertain sex found in sandstone that are slightly larger than those preserved in siltstone belong to the leaves of Credneria. Association evidence links vegetative and reproductive structures preserved in siltstone and indicates the presence of the modern genus Platanus in the Santonian. [Copyright &y& Elsevier]

Dispersed pollen, fruits, and leaves of Tetracentron (Trochodendraceae) are described from the Miocene of Iceland and assigned to a new species, Tetracentron atlanticum. The Icelandic fossils represent the first unambiguous record of Tetracentron for the Cainozoic of Europe. Well-preserved dispersed grains of Tetracentron are also identified from the Eocene and Miocene of western North America and compared to the Icelandic fossils. In general, Tetracentron pollen is rather uniform through the Eocene to Recent, only displaying minor variation in ornamentation. Leaves are diagnostic at the species level. The findings add substantial new information to the generally poor fossil record of Tetracentron and indicate a more circumpolar distribution of the genus than previously assumed. The north-eastern Asian - western North American Cainozoic distribution for plant taxa presently confined to East Asia is relatively common. In contrast, the extension to Iceland is remarkable, particularly in view of the absence of the genus in the fossil record from eastern North America, Greenland, and Central Asia and mainland Europe. [ABSTRACT FROM AUTHOR]