Assessment of Phytogeographic Reference Regions for Cenozoic vegetation: a case study on the Miocene flora of Wiesa (Germany)
Abstract
During the Miocene Climatic Optimum, a global long-term warm interval, European mid-latitude regions experienced a subtropical palaeoclimate. In particular, areas in eastern Germany were part of a vegetational zone with evergreen broadleaved forests, characterized by subtropical taxa. Regional palaeofloristic concepts denominated this palaeovegetation Younger Mastixioideae Flora sensu Mai (1964). Type assemblage is the late Early Miocene flora of Wiesa. Here, we reevaluate its floristic composition with respect to nearest living relatives of fossil-taxa, and introduce the new approach Phytogeographic Reference Region Assessment (PRRA) to ascertain the area of most similar extant vegetation for the Wiesa assemblage. The southern belt of SE Asian subtropical evergreen broadleaved forest and its transition to tropical mountain evergreen broadleaved forest in SW China represent the most similar extant vegetation. The Wiesa assemblage is compared to two diverse plant macroassemblages from the late Oligocene and the Late Miocene, respectively, coming from the same region and palaeoenvironmental setting. It is demonstrated that diversity and abundances of subtropical taxa markedly increased towards the Early Miocene, and specific climate-sensitive taxa occurred. The regional palaeoclimate was subtropical-humid (Köppen-Trewartha type Cf), with a growing season eleven months long. The late Oligocene and Late Miocene climates were mainly distinct in nine-month growing season lengths and cooler winters (1–3 °C).
Key words
Phytogeographic Reference Region Assessment, Younger Mastixioideae Flora, Borna-Ost/Bockwitz, Wischgrund, Miocene Climatic OptimumThe type of Palmocarpon cretaceum Miq., 1853 described from the Cretaceous of the Sint-Pietersberg, The Netherlands, is an Eocene Nypa burtinii (Brongn.) Ettingsh., 1879, most likely from the Brussels area, Belgium
Abstract
The study of a few putative palm macrofossils from the type area of the Maastrichtian Stage appeared to have important implications for understanding the composition of the fossil flora of the area, as well as for the nomenclature of fossil palm fruits in general. The type specimen of the palm fruit Palmocarpon cretaceum Miq., 1853 described from the Cretaceous of the Maastrichtian type area belongs to Nypa burtinii (Brongn.) Ettingsh., 1879 from the Eocene, most probably from the Brussels area. The material mentioned by Ubaghs (1885a, b, 1887) as Palmocarpon cretaceum does not represent fossil palm fruits. Therefore, palm pollen is the only evidence for the presence of palms (Arecaceae, or Palmae, excl. Nypa) in the Cretaceous of the Maastrichtian type area. Palmocarpon Miq., 1853 is proposed here as a nomen rejiciendum, and the genus Palmocarpon Lesq., 1878 as a nomen conservandum.
Key words
palm fruit, Palmocarpon, Nypa, Cretaceous, Eocene, The Netherlands, Belgium, Maastrichtian type area, Brussels areaThe early middle Eocene Wagon Bed carpoflora of central Wyoming, U.S.A.
Abstract
The early middle Eocene Wagon Bed fruit and seed flora of central Wyoming encompasses nine morphotypes that are assignable to extant genera (Alangium, Aphanathe, Canarium, Carya, Celtis, Iodes, Mastixia, Nyssa, Pleiogynium), four that are assignable to extinct genera in extant families (Chandlera, Menispermaceae; Coryloides, Betulaceae; Pentoperculum, Anacardiaceae; Saxifragispermum, Salicaceae) and one morphotype potentially assignable to an extant family (Pandanaceae). At least 11 morphotypes remain unidentified due to incomplete characters, although some exhibit features suggestive, but not definitive, of extant families (e.g., Euphorbiaceae, Lauraceae, Nymphaeaceae, Rosaceae). Individual taxa exhibit paleobiogeographic links with the Eocene floras of the west coast of North America, as well as with those of the Eocene of Europe. Together with previously described pollen and woods, these fruits and seeds indicate a mixed evergreen and deciduous forest, existing under moist circumstances, possessing primary taxonomic affinities with extant paratropical taxa of the Old World.
Key words
fossil fruit, fossil seed, Eocene, Wyoming, Cannabaceae, Carya, Juglandaceae, Mastixiaceae, Menispermaceae, ?Pandanaceae, Salicaceae, Spondioid AnacardiaceaeFlora, vegetation and climate assessment of the Early/Middle Miocene Parschlug flora indicates a distinctly seasonal climate
Abstract
The late Early/early Middle Miocene flora from Parschlug (Styria, Austria) is famous for its numerous specimens and high diversity. Some taxa previously described are revised here and 42 new angiosperm leaf morphotypes/taxa are described. The Climate Leaf Analysis Multivariate Program (CLAMP) is applied to assess the palaeoclimate. An update of the tool to assess the most suitable modern climate CLAMP calibration dataset is introduced. The Integrated Plant Record (IPR) vegetation analysis, assessing the most likely major vegetation type represented by a fossil flora, and similarity approaches Drudges 1 and 2, indicating the most similar modern vegetation proxies, had been previously applied to data from Parschlug. Both are again applied here on the enlarged floristic spectrum. The results indicate “sclerophyllous subhumid forest” as the most likely major zonal vegetation type for Parschlug and European vegetation, namely “Thermophilous mixed deciduous broadleaved forests”, distributed today in southern and southeastern Europe, as the most similar modern vegetation. The climate for Parschlug, inferred from CLAMP and the climate in the region of the modern vegetation proxies, indicates distinct seasonality in precipitation and temperature.
Key words
leaf flora, CLAMP, IPR vegetation analysis, Drudges, modern vegetation and palaeoclimate proxies, Neogene, AustriaA whole-plant specimen of the marine macroalga Pterigophycos from the Eocene of Bolca (Veneto, N-Italy)
Abstract
Uncalcified macroalgae are generally rare as fossils, and hence their past diversity and evolutionary history remain poorly resolved. The Bolca area in northern Italy has yielded abundant adpression fossils of Eocene macroalgae. However, the vast majority of specimens are detached blades and blade portions. Here, we present an almost complete thallus of the macroalga Pterigophycos from Bolca that consists of a squat holdfast from which leaf-like blades up to 30 cm long extend. Each blade has a midrib extending over its entire length. Proximally the lamina forms a narrow rim on each side of the midrib, but becomes wider and lobed in the lower mid-portion. In the upper three quarters of the blade the lamina consists of spathulate or wedge-shaped segments. Pterigophycos blades have certain features in common with the present-day Phycodrys rubens, Delesseria sanguinea (both Ceramiales, Rhodophyta), Undaria pinnatifida, and Egregia menziesii (both Laminariales, Phaeophyceae); however, the systematic affinity of the fossil remains unresolved. The fossil is suggestive of intraspecific variability in blade morphology, and thus contests the historic view that there are several different species of Pterigophycos in the Bolca flora.
Key words
holdfast, Rhodophyta, thallus, uncalcified macroalga, Lessini Mountains, YpresianRemains of a subtropical humid forest in a Messinian evaporite-bearing succession at Govone, northwestern Italy – Preliminary results
Abstract
The first results of a multidisciplinary study on the Messinian evaporitic interval of the Govone section (northwestern Italy), subdivided into several sedimentary cycles, are reported here. Primary sulphate evaporites and intercalated shaly deposits, which formed during the Messinian Salinity Crisis, contain well-preserved and taxonomically determinable terrestrial plant remains. Palynomorphs are present continuously all along the analysed succession and among them, pollen is especially abundant and diverse. Additionally, a few fragments of silicified wood (which are rare in the studied area) occurred in layers rich in phytodebris, but their analysis showed poor preservation of anatomy. Carpological remains are not abundant and are strongly altered by diagenesis. Compressed conifer shoots and angiosperm leaves are well-preserved in several layers, one of which yielded a particularly diverse assemblage. The various plant records have been integrated to obtain an initial general idea on the floristic composition of the assemblages and the palaeoenvironment. We hypothesize that a subtropical humid forest may have surrounded the basin, not only during the deposition of shale deposits, but also during the formation of gypsum, generally considered a product of arid climate. Despite the low-resolution sampling strategy for macrofossils, the identification of several relevant plant taxa (Engelhardia orsbergensis, Eurya stigmosa, Symplocos casparyi, Taiwania sp.), seems to indicate that the Govone section could provide an interesting glimpse into the composition of the palaeoflora of northern Italy during the deposition of the Messinian evaporites.
Key words
palaeobotany, leaves, carpology, palynology, fossil wood, Messinian Salinity Crisis, MioceneLate Messinian flora from the post-evaporitic deposits of the Piedmont Basin (Northwest Italy)
Abstract
In the Piedmont Basin (PB), one of the northernmost Mediterranean basins recording the Messinian Salinity Crisis (MSC), pollen and plant macroremains (leaves, fruits and seeds) were studied in four sedimentary sections of the post-evaporitic interval (5.6–5.33 Ma). The joint palaeobotanical investigations of the two datasets allowed the reconstruction of a floristic assemblage which consists of 133 taxa (95 woody and 38 non-woody taxa). The lowland/coastal vegetation reconstructed by integrating macro- and microfossil data exhibits several analogies with existing “types/formations” of South-Southeast Asia, whereas taxa occurring solely in the pollen record suggest the existence of altitudinal forests with conifers and a few angiosperms. We suggest that the generalized type of lowland, zonal palaeovegetation in the post-evaporitic Messinian of the PB was of no-analog type, but most similar to either “mixed mesophytic forests” or “broad-leaved evergreen forests”, which indicates a Köppen-Trewartha subtropical palaeoclimate.
Key words
palaeobotany, carpology, palynology, whole-plant concept, Messinian Salinity Crisis, palaeoenvironmentThe late Early Pleistocene flora of Oriolo, Faenza (Italy): assembly of the modern forest biome
Abstract
The late Early Pleistocene was the last time of equable climate in northern Central Italy, reflected in its large mammal fauna and numerous palynological records. Reliably dated leaf fossils from this time are rare, but provide crucial information on local and regional vegetation, biogeographic relationships, and species turnover coinciding with the assembly of modern forest biomes. Here we investigated a rich assemblage of leaf and fruit impressions (63 fossil-taxa) from the Oriolo quarry, Faenza (Ravenna), dated to the latest Calabrian, preserved in transgressive coastal deposits. The fossil assemblage represents riparian vegetation and xeric alluvial habitats in the lowlands and forest vegetation above the alluvial plain. Forest-building trees were deciduous, but comprised several taxa characteristic of open scrubland or forest edges. The composition of the flora reflects a dynamic process of assembling modern forest biomes in western Eurasia. While most taxa correspond to modern submediterranean and temperate woody species, some others represent late occurrences of taxa today confined to refugia outside Italy (Parrotia, Gleditsia, Pterocarya), and a few are Miocene/Pliocene relics indicating final floristic links with East Asia (Japan) and/or North America (Tsuga cf. chiarugii, Carya cf. minor) and Pleistocene endemism in Italy (Berberis auriolensis, Acer aemilianum).
Key words
Angiosperms, leaves, fruits, Early to Middle Pleistocene, Italy, Integrated Plant Record (IPR) vegetation analysis, statistical tool Drudge 1, Pleistocene relict taxaA new Early Miocene (Ottnangian) flora of the “Rzehakia Beds” from Brno-Líšeň
Abstract
The fossil flora from brackish late Burdigalian (Ottnangian) sediments in Brno-Líšeň (the Czech Republic) contributes to our knowledge of floristic evolution and palaeoclimatic changes in the Western Carpathians. The fossil material investigated for this study comprises fragmentary leaf imprints, few fruits/seeds, and dispersed pollen from a single palynomorph-rich sample. Macro remains include 3 ferns (Osmunda parschlugiana, Salvinia reussii, ?Polypodiaceae gen. et sp. indet.) and 17 angiosperms (e.g., Daphnogene polymorpha, “Parrotia” pristina, Leguminophyllum spp., Podocarpium podocarpum, cf. Engelhardia orsbergensis, Ulmus sp., Schoenoplectiella cf. ragozinii). The palynospectrum comprises 106 taxa, including abundant palaeotropical elements of zonal evergreen forest, i.e., Sapotaceae, Palmae, Engelhardia, Platycarya, Fagaceae, Araliaceae and Cornus-Mastixia, accompanied by arctotertiary elements of deciduous zonal forest (Quercus, Carpinus, Fagus, Carya, Juglans, Tilia, Betula, Parrotia) and deciduous azonal (riparian) forest (e.g., Alnus, Salix, Ulmus). Aquatic plants, algae (Prasinophyceae, Botryococcus) and marine dinoflagellates indicate a marine environment with freshwater impact. Plant taxa possibly representing open areas such as Olea, Celtis, Buxus, Ephedra, Rosaceae and Poaceae are sporadic, as well as conifers of extrazonal forest such as Cedrus, Tsuga, Picea. The studied palynospectrum contains abundant thermophilic elements and does not point to a cooling event, as reported by previous authors from the Polish part of the Carpathian Foredeep.
Key words
fossil flora, leaves, fruits, pollen, palaeoenvironment, Early Miocene, Carpathian Foredeep, ParatethysFirst water lily, a leaf of Nymphaea sp., from the Miocene Clarkia flora, northern Idaho, USA: Occurrence, taphonomic observations, floristic implications
Abstract
Although the Miocene Clarkia locality in Idaho, USA, is a well-known fossil lagerstätte, this 16-million-year-old flora is especially renowned for its abundant leaves with excellent preservation. The exquisite condition of its dicot leaves has resulted in detailed research on systematics, morphology, venation, epidermal structure, cell ultrastructure, biochemistry, and even molecular biology. However, new discoveries continue to emerge, even after five decades of research. Here we describe the first water lily leaf from the Clarkia flora as Nymphaea sp. based on its form, petiole attachment, and venation. The eccentric peltate leaf is ovate with a cordate base, a deep basal sinus, entire margins, and actinodromous primary venation. Its small, unblemished condition and leathery texture suggests that it is a young floating leaf. While rare in the Clarkia Lake deposits, the occurrence of a single water lily leaf among tens of thousands of dicot and conifer leaves follows the taphonomic pattern of nearby Middle Miocene floras, two of which have yielded Nymphaea pollen. The recognition of Nymphaea at Clarkia supplements the taxonomic composition of the flora, confirms the presence of water lilies in region during the Middle Miocene, and completes our understanding of plant life in the Pacific Northwest 16 million years ago.
Key words
Clarkia local flora, Columbia River Basalt Group, fossil aquatic macroflora, fossil aquatic macrophyte, leaf fossil, Miocene Climatic Optimum, Nymphaeaceae, Nymphaeales, plant taphonomy, Wanapum FormationThe late Oligocene macroflora of Zsámbék, central Hungary
Abstract
Fossil plants were discovered by geologists in the dolomite quarry on Strázsa Hill, west of Zsámbék, central Hungary, during December, 2020. The analysis of the plant remains and subsequent field studies suggest that the fossil plants are preserved in sediments of the Mány Member of the Törökbálint Formation and the sandy-clayey layers overlying Mesozoic dolomites were formed during the Oligocene. The fossil plant assemblage includes a small number of taxa with a relatively high frequency of gymnosperms. Among the gymnosperms taxodiaceous twigs, assigned to ?Taxodium, are dominant. Angiosperms are represented by the family Lauraceae (Daphnogene and Laurophyllum), Betulaceae (cf. Alnus), Ulmaceae (cf. Ulmaceae gen. et sp.), and “Rhamnus” warthae, a taxon with unknown systematic relations and a putative endemic element of the Intra-Carpathian area of the Central Paratethyan region. The flora is dominated by gymnosperms and “Rhamnus” warthae, other taxa are present but at lower frequency. Although the plant fossils of Zsámbék represent wetland vegetation types, less suitable for climate reconstruction, the relatively high ratio of lauraceous elements suggests a frostfree, warm climate. The floristic composition of the Zsámbék flora is clearly comparable to other late Oligocene floras of Hungary, therefore earlier climate estimates based on other similar-aged floras may also be considered for Zsámbék.
Key words
Chattian, Egerian, Kiscellian, taxodiaceous gymnosperms, Lauraceae, Daphnogene, “Rhamnus” warthae, wetland, Transdanubian Range, Törökbálint FormationMastixioid fruits (Cornales) from the early Eocene London Clay Flora: morphology, anatomy and nomenclatural revision
Abstract
Following on the seminal works of Reid and Chandler in 1933 and Chandler in 1961, morphology and anatomy of fossil mastixioid fruits from the early Eocene London Clay of southern England were reanalyzed with the benefit of new methods in comparison with extant genera of Mastixiaceae and with other fossil representatives from Europe and North America. The species named Mastixia cantiensis E.Reid et M.Chandler was based on a heterogeneous assemblage of specimens, all representing Mastixiaceae, some of which truly represent Mastixia whilst others correspond to Diplopanax and Mastixiopsis The holotype of M. cantiensis E.Reid et M.Chandler corresponds to extant Diplopanax rather than Mastixia. Therefore, this species is moved out of Mastixia and is treated as Diplopanax cacaoides (Zenker) comb. nov. Nine species of mastixioid fruits are currently recognized in the London Clay flora: Mastixia parva E.Reid et M.Chandler, M. cf. oregonensis (R.A.Scott) Tiffney et Haggard, Diplopanax cacaoides, Tectocarya grandis (E.Reid et M.Chandler) comb. nov., Mastixiopsis nyssoides Kirchh., Exbeckettia mastixioides (E.Reid et M.Chandler) gen. et comb. nov., Lanfrancia subglobosa E.Reid et M.Chandler, Portnallia bognorensis M.Chandler, and Langtonia bisulcata E.Reid et M.Chandler. These include the oldest known representatives of the genera Diplopanax, Tectocarya and Mastixiopsis and contribute to our understanding of the former morphological diversity and palaeobiogeography of the Mastixiaceae.
Key words
Beckettia, biogeography, Diplopanax, Exbeckettia, Lanfrancia, Langtonia, Mastixia cantiensis, Mastixiaceae, Mastixiopsis, Portnallia, taxonomy, Tectocarya grandisEvidence for wildfires during deposition of the late Miocene diatomites of the Konservat- Lagerstätte Lake Saint-Bauzile (Ardèche, France) – preliminary results
Abstract
The freshwater diatomite deposits from Saint-Bauzile in the Ardèche (France) represent a first-class Fossil-Lagerstätte of late Miocene, i.e., Tortonian age. A large variety of different animals (i.e., insects, fishes, and mammals) and macro-plants as well as palynomorphs and lacustrine diatoms are known from this locality, in generally excellent preservation. This contribution presents preliminary results on charred plant remains, i.e., charred fern and grass remains, as well as partly charred wood of taxodioid cupressacean affinity, as evidence for the occurrence of wildfire(s) during deposition of the lower part of the diatomite sequence. Previously published volcanological and sedimentological evidence for the interpretation of Lake Saint-Bauzile as a maar is reviewed, re-interpreted, and discussed in combination with new observations.