Pliocene Lythrum (loosestrife, Lythraceae) pollen from Portugal and the Neogene establishment of European lineages

Funding Information: We thank Guido W. Grimm, Orleans, France for commenting an earlier version of this manuscript, and two anonymous reviewers for their suggestions to improve this manuscript. Publisher Copyright: © 2021 The AuthorsThe fossil record of Lythrum is scarce and every new find brings an extra piece of the puzzle to the obscure phytogeographic history of this genus. Lythrum pollen is unique and has the potential to be recognized in palynological assemblages. Therefore, the few pre-Holocene fossil records are all pollen described from North America, Russia, and Europe. The European records are both most numerous and geologically younger than those from other parts of the Northern Hemisphere. Earliest European Lythrum pollen records are of late Miocene age and parallel to starting crown group radiation in the Eurasian clade of Lythrum. European Miocene to Pliocene Lythrum pollen morphology is comparable to that of extant species. Interestingly, the late Miocene expansion of Lythrum into Europe coincides with the decline of Decodon, and Lythrum appears to replace Decodon in late Neogene fossil palynological assemblages.publishersversionpublishe

How to extract and analyze pollen from internal organs and exoskeletons of fossil insects

This protocol explains how to extract pollen from fossil insects with subsequent descriptions of pollen treatment. We also describe how to document morphological and ultrastructural features with light-microscopy and electron microscopy. It enables a taxonomic assignment of pollen that can be used to interpret flower-insect interactions, foraging and feeding behavior of insects, and the paleoenvironment. The protocol is limited by the state of the fossil, the presence/absence of pollen on fossil specimens, and the availability of extant pollen for comparison. For complete details on the use and execution of this protocol, please refer to Wappler et al. (2015), Ulrich and Grímsson (2020), and Wedmann et al. (2021)

Niche evolution versus niche conservatism and habitat loss determine persistence and extirpation in late Neogene European Fagaceae

Funding Information: We thank the two anonymous reviewers for helpful comments. TD acknowledges financial support from the Swedish Research Council (grants number 2015-03986 , 2021–05849 ). Publisher Copyright: © 2022 The AuthorsAn increasing body of palaeobotanical data demonstrates a series of Pliocene and Pleistocene extirpations and extinctions of plant lineages in western Eurasia, which are believed to have been determined by the climatic properties of their related East Asian and North American sister lineages. We investigated the diversity of a widespread northern hemispheric plant family, Fagaceae, during the Late Pliocene of Portugal. We found a high diversity of Fagaceae comprising extant and extinct lineages. Dispersed pollen of Castanopsis and Quercus sect. Cyclobalanopsis represent the youngest records of these Himalayan-Southeast Asian groups in western Eurasia. Likewise, fossil-species of Quercus sect. Lobatae and the North American clade of sect. Quercus are the youngest records of these modern New World groups in western Eurasia. For the extinct Trigonobalanopsis, the pollen record of Portugal is the youngest known of this genus. Climate data of modern representatives demonstrate that a deterministic model can explain only a part of the Pliocene and Pleistocene extirpations. Modern cold month mean temperatures of Castanopsis and Quercus sect. Cyclobalanopsis and their last occurrences in western Eurasia in the Pliocene fit with a deterministic model (niche conservatism). In contrast, survival or extirpation of groups with high cold tolerance appear to have been more complex. Here, niche evolution, abundance and diversity of a lineage during pre-Pleistocene times, and habitat availability/loss determined the fate of Fagaceae lineages in western Eurasia.publishersversionpublishe

Tiny pollen grains: first evidence of Saururaceae from the Late Cretaceous of western North America

Background The Saururaceae, a very small family of Piperales comprising only six species in four genera, have a relatively scanty fossil record outside of Europe. The phylogenetic relationships of the four genera to each other are resolved, with the type genus Saururus occurring in both eastern North America and East Asia. No extant species occurs in western Eurasia. The most exceptional find so far has been an inflorescence with in-situ pollen, Saururus tuckerae S.Y.Sm. & Stockey from Eocene of North America with strong affinities to extant species of Saururus. Recent dated trees suggest, however, an Eocene or younger crown age for the family. Methods Dispersed fossil pollen grains from the Campanian (82–81 Ma) of North America are compared to dispersed pollen grains from the Eocene strata containing S. tuckerae, the Miocene of Europe, and extant members of the family using combined LM and SEM imaging. Results The unambiguous fossil record of the Saururaceae is pushed back into the Campanian (82–81 Ma). Comparison with re-investigated pollen from the Eocene of North America, the Miocene of Europe, and modern species of the family shows that pollen morphology in Saururaceae is highly conservative, and remained largely unchanged for the last 80 million years. Discussion Campanian pollen of Saururaceae precludes young (Eocene or younger) estimates for the Saururaceae root and crown age, but is in-line with maximum age scenarios. Saururus-type pollen appear to represent the primitive pollen morphology of the family. Often overlooked because of its small size, dispersed Saururaceae pollen may provide a unique opportunity to map the geographic history of a small but old group of Piperales, and should be searched for in Paleogene and Cretaceous sediment samples

Specialized and Generalized Pollen-Collection Strategies in an Ancient Bee Lineage

This work is licensed under a Creative Commons Attribution Non-Commercial-No Derivatives 4.0 International License.Iconic examples of insect pollination have emphasized narrowly specialized pollinator mutualisms such as figs and fig wasps [1] and yuccas and yucca moths [2]. However, recent attention by pollination ecologists has focused on the broad spectra of pollinated plants by generalist pollinators such as bees. Bees have great impact for formulating hypotheses regarding specialization versus generalization in pollination mutualisms [3, 4]. We report the pollination biology of six northern European species of an extinct tribe of pollen-basket-bearing apine bees, Electrapini, of early–middle Eocene age, examined from two deposits of 48 and 44 million years in age [5]. These bees exhibit a pattern of generalized, incidental pollen occurring randomly on their heads, thoraces, and abdomens, obtained from diverse, nectar-bearing plants. By contrast, a more restricted suite of pollen was acquired for metatibial pollen baskets (corbiculae) of the same bee taxa from a taxonomically much narrower suite of arborescent, evergreen hosts with uniform flower structure. The stereotyped plant sources of the specialist strategy of pollen collection consisted of pentamerous, radially symmetrical flowers with a conspicuous gynoecium surrounded by prominent nectar reward, organized in structurally similar compound inflorescences. Pollen specialization in bees occurs not for efficient pollination but rather in the corbiculate Electrapini as food for bee larvae (brood) and involves packing corbiculae with moistened pollen that rapidly loses viability with age. This specialist strategy was a well-developed preference by the early Eocene, providing a geochronologic midpoint assessment of bee pollen-collection strategies

Hagenia from the early Miocene of Ethiopia: evidence for possible niche evolution?

Fossil pollen believed to be related to extant Hagenia abyssinica were discovered in the early Miocene (21.73 Ma) Mush Valley paleoflora, Ethiopia, Africa. Both the fossil and extant pollen grains of H. abyssinica were examined with combined light microscopy, scanning electron microscopy, and transmission electron microscopy to compare the pollen and establish their relationships. Based on this, the fossil pollen grains were attributed to Hagenia. The presence of Hagenia in the fossil assemblage raises the questions if its habitat has changed over time, and if the plants are/were wind pollinated. To shed light on these questions, the morphology of extant anthers was also studied, revealing specialized hairs inside the anthers, believed to aid in insect pollination. Pollen and anther morphology are discussed in relation to the age and origin of the genus within a molecular dated phylogenetic framework, the establishment of complex topography in East Africa, other evidence regarding pollination modes, and the palynological record. The evidence presented herein, and compiled from the literature, suggests that Hagenia was an insect‐pollinated lowland rainforest element during the early Miocene of the Mush Valley. The current Afromontane habitat and ambophilous (insect and wind) pollination must have evolved in post‐mid‐Miocene times

Illustrated Pollen Terminology

This open access book offers a fully illustrated compendium of glossary terms and basic principles in the field of palynology, making it an indispensable tool for all palynologists. It is a revised and extended edition of “Pollen Terminology. An illustrated handbook,” published in 2009. This second edition, titled “Illustrated Pollen Terminology” shares additional insights into new and stunning aspects of palynology. In this context, the general chapters have been critically revised, expanded and restructured. The chapter “Misinterpretations in Palynology” has been extended with new research data and additional ambiguous terms, e.g., polyads vs. massulae; the chapter “Methods in Palynology” has been extensively enhanced with illustrated protocols showing the majority of the methods and techniques used when studying recent and fossil pollen with LM, SEM and TEM. Moreover, additional information about the description and publication of pollen data is provided in the chapter “How to Describe and Illustrate Pollen Grains.” Various other parts of the general chapters have now been updated and/or extended with more comprehensive textual passages and new illustrations. The chapter “Illustrated Pollen Terms” now features new and more appropriate examples of each term, including additional LM micrographs. Where necessary, the entries for selected pollen terms have been refined by rewording or adding definitions, illustrations, and new micrographs. Lastly, new terms are included, such as “suprasculpture” and the prefix “nano-“ for ornamentation features. The chapter “Illustrated Pollen Terms” is the main part of this book and comprises more than 300 widely used terms illustrated with over 1,000 high-quality images. It provides a detailed survey of the manifold ornamentation and structures of pollen, and offers essential insights into their stunning beauty

Paleovegetation and paleoclimate inferences of the early late Sarmatian palynoflora from the Gleisdorf Fm. at Gratkorn, Styria, Austria

The Gleisdorf Formation (Fm.) deposits in the clay pit at Gratkorn, Styria, Austria, are dated to 12.2–12 Ma,and are of late Middle Miocene age (late Serravallian or Sarmatian). To reconstruct the paleovegetation and estimate the paleoclimate at this important vertebrate site, the palynoflora close to the boundary between the vertebrate-bearing layers of the Gratkorn Fm. and the overlying limnic clay deposits of the Gleisdorf Fm. was investigated. Using the single-grain method, 140 palynomorphs were identified. The palynoflora suggests that the paleovegetation was characterised by well-drained lowland and upland forests, riparian forest, and swamp forests. Depending on the dominating tree species, lowland and upland forests might have had closed or more open canopies. Open habitats included wet meadows and shrublands. In addition, conifers were present in theswampy lowlands and the forested uplands. The most prominent paleoclimatic signatures of the palynoflora indicate a fully humid warm temperate climate, with hot to warm summers and cool winters (Cfa-, Cfb-climate), and a seasonal climate with cool and drier winters and hot to warm and wetter summers (Cwa-, Cwb-climate). Our results align with existing studies bordering the Styrian Basin and support the presence of subtropical to warm-temperate vegetation around Gratkorn during the Sarmatian

The first Loranthaceae fossils from Africa

<p>An ongoing re-investigation of the early Miocene Saldanha Bay (South Africa) palynoflora, using combined light and scanning electron microscopy (single grain method), is revealing several pollen types new to the African fossil record. One of the elements identified is Loranthaceae pollen. These grains represent the first and only fossil record of Loranthaceae in Africa. The fossil pollen grains resemble those produced by the core Lorantheae and are comparable to recent Asian as well as some African taxa/lineages. Molecular and fossil signals indicate that Loranthaceae dispersed into Africa via Asia sometime during the Eocene. The present host range of African Loranthaceae and the composition of the palynoflora suggest that the fossil had a range of potential host taxa to parasitise during the early Miocene in the Saldanha Bay region.</p