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Two new isoetalean (Lycopsida) megaspore species representing the earliest occurrence of Henrisporites from upper Permian strata of Southwest China
No full textTwo distinctive lycopsid megaspore species, Henrisporites yunnanensis Sui, McLoughlin et Feng sp. nov. and H. qujingensis Sui, McLoughlin et Feng sp. nov., are described from the Lopingian Xuanwei Formation of Yunnan Province, Southwest China, using scanning and transmission electron microscopy. Henrisporites yunnanensis is characterized by prominent membranous triradiate labra with ragged margins, a broad irregularly serrated membranous zona with radiating spiny extensions, and ramified or unbranched spines on the spore surface, those on the distal surface especially having capillate termini. Punctatisporites-type microspores occur adhering to the megaspore surface. The megaspore wall incorporates four layers, viz., from inside to outside: (1) a thin and dense foot layer especially thickened at the laesurae lips; (2) a moderately-thick layer with small circular and loosely distributed sporopollenin grains with parallel arrangement; (3) a thick spongy layer consisting ofelongate, curved and interconnected sporopollenin units perpendicular to the inner layers; and (4) an electron-dense outermost layer forming the ornamentation. Henrisporites qujingensis has lower membranous labra, a generally continuous membranous zona with radiate spiny margins but, in some cases, dissected into single fimbria, and bearing sparsely distributed and locally forked stubby spines over the spore surface. Henrisporites qujingensis also has a four-layered wall. The innermost thin foot layer is covered by a loose layer of tiny parallel sporopollenin grains. A thick spongy layer is developed exterior to the second layer and comprises elongate, curved, and intersecting sporopollenin units forming a porous zone. The outermost layer consists of varied sculptural processes with contrasting densities between the proximal and distal surfaces. The morphological and ultrastructural characteristics suggest that these new megaspores belong to Isoetales. Our discovery represents the earliest global occurrence of Henrisporites, which has been documented exclusively from the Mesozoic in previous studies.This study was jointly supportedby the Strategic Priority Research Program of Chinese Academy of Sciences (XDB26000000), the Second Tibetan Plateau Scientific Expedition and Research (2019QZKK0706), the Key Research Programof the Institute of Geology and Geophysics, Chinese Academy of Sciences (IGGCAS-201905), the China Scholarship Council (grant number 202207030014), and the Graduate Research Innovation Project of Yunnan University. S.M. is funded by grants from the Swedish Research Council (VR grantnumbers 2018-04527 and 2022-03920).</p
Specialized herbivory in fossil leaves reveals convergent origins of nyctinasty
No full textPlants can move in various complex ways in response to external stimuli. These mechanisms include responses to environmental triggers, such as tropic responses to light or gravity and nastic responses to humidity or contact. Nyctinasty, the movements involving circadian rhythmic folding at night and opening at daytime of plant leaves or leaflets, has attracted the attention of scientists and the public for centuries. In his canonical work entitled The Power of Movement in Plants, Charles Darwin carried out pioneering observations to document the diverse range of movements in plants. His systematic examination of plants showing ‘‘sleep [folding] movements of leaves’’ led him to conclude that the legume family (Fabaceae) includes many more nyctinastic species than all other families combined. Darwin also found that a specialized motor organ, the pulvinus, is responsible for most sleep movements of plant leaves, although differential cell division and the hydrolysis of glycosides and phyllanthurinolactone also facilitate nyctinasty in someplants. However, the origin, evolutionary history, and functional benefits of foliar sleep movements remain ambiguous owing to the lack of fossil evidence for this process. Here, we document the first fossil evidence offoliar nyctinasty based on a symmetrical style of insect feeding damage (Folifenestra symmetrica isp. nov.) in gigantopterid seed-plant leaves from the upper Permian (c. 259–252 Ma) of China. The pattern of insect damage indicates that the host leaves were attacked when mature but folded. Our finding reveals that foliar nyctinasty extends back to the late Paleozoic and evolved independently among various plant lineages.This study was supported jointly by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB26000000), the Second Tibetan Plateau Scientific Expedition and Research (2019QZKK0706), and the Key Research Program of the Institute of Geology and Geophysics, Chinese Academy of Sciences (IGGCAS-201905). S.M. was funded by grants from the Swedish Research Council (VR grant numbers 2018-04527 and 2022-03920).</p
New biogeochemical proxies in seep bivalves
No full textReduced compounds dissolved in seeping fluids, such as methane and hydrogen sulfide, are the main energy sources in submarine cold seep systems, where they nourish the unique chemosynthesis-based ecosystems. Chemosymbiotic bivalves are the dominant macrofauna in many of these ecosystems and have been extensively studied due to their large biomass (hundreds of individuals per square meter), their symbiotic relationships with chemotrophic bacteria (methanotrophic bivalves: methane-oxidizing bacteria; thiotrophic bivalves: sulfur-oxidizing bacteria), and because they are unique archives of biogeochemical processes. In this chapter, we briefly introduce the advancements in seep bivalve research worldwide and then summarize the trophic modes and geographic distribution of seep bivalves in the South China Sea. Thereafter, the biogeochemical processes, such as the enzymatic strategy and energy transfer of seep bivalves, are generalized by integrating the trace elements and stable isotope data of the soft tissues and their corresponding calcareous shells of seep bivalves. Overall, we highlight the past contributions and current knowledge in this field and outline opportunities and future directions to expand this area of research.Funding was provided by the National Natural Science Foundation of China (Grant: 42106059), Shanghai Sailing Program (Grant: 21YF1416800) and Chenguang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission (Grant: 22CGA58).</p
Cenozoic migration of a desert plant lineage across the North Atlantic
No full textPrevious paleobotanical work concluded that Paleogene elements of the sclerophyllous subhumid vegetation of western Eurasia and western North America were endemic to these disjunct regions, suggesting that the southern areas of the Holarctic flora were isolated at that time. Consequently, molecular studies invoked either parallel adaptation to dry climates from related ancestors, or long-distance dispersal in explaining disjunctions between the two regions, dismissing the contemporaneous migration of dry-adapted lineages via land bridges as unlikely. We report Vauquelinia (Rosaceae), currently endemic to western North America, in Cenozoic strata of western Eurasia. Revision of North American fossils previously assigned to Vauquelinia confirmed a single fossil-species of Vauquelinia and one of its close relative Kageneckia. We established taxonomic relationships of fossil-taxa using diagnostic character combinations shared with modern species and constructed a time-calibrated phylogeny. The fossil record suggests that Vauquelinia, currently endemic to arid and subdesert environments, originated under seasonally arid climates in the Eocene of western North America and subsequently crossed the Paleogene North Atlantic land bridge (NALB) to Europe. This pattern is replicated by other sclerophyllous, dry-adapted and warmth-loving plants, suggesting that several of these taxa potentially crossed the North Atlantic via the NALB during Eocene times
On the types of Bolboceratidae (Coleoptera: Scarabaeoidea) in the Swedish Museum of Natural History in Stockholm
No full textThe investigation of the Bolboceratidae collection of the Stockholm Museum of Natural History (NHRS) yielded 12 type specimens of eight Afrotropical and one Australian species. The majority of these types belongs to species described by Carl Henrik Boheman (1796–1868) based on specimens collected by Johan August Wahlberg (1810–1856) in southern Africa. In two of these species, we found ambiguity among potential syntypes. Therefore, based on comparison with original descriptions, we designate lectotypes for Bolboceras caffrum Boheman, 1857 and Bolboceras exasperans Péringuey, 1908, both of which are today classified in the genus Bolbocaffer Vulcano, Martínez & Pereira, 1969. Finally, we establish Bolboceras matabele Péringuey, 1908 (syn. nov.) as a junior subjective synonym of B. exasperans, we confirm a few synonymies that were historically established without study of type specimens, and we resurrect Bolboceras dorsuale Boheman, 1857 from previous synonymy under B. maculicolle Boheman, 1857 (Mimobolbus dorsualis (Boheman, 1857) n. comb. and stat. rev.).
H2 - ENVIRONMENTAL AND ENERGY CHALLENGESOF THE XXI CENTURY. GLOBAL PROJECTSWAYS OF IMPLEMENTATION
No full textThe research studied the pressing problem of the fuel and energy strategy of the XXI century. For the first time, there was shown the diversity of the authors' approach to theoretical and applied problems of hydrogen energy. General issues of fundamental and applied aspects of hydrogen origin were covered. The study provides the results of scientific developments on hydrogen mapping performed within the framework of scientific and practical exploratory and geo-ecological research on more than 200 hydrocarbon objects both on land (including mining fields) and in marine water areas. Prognostic and search system criteria were substantiated, with hydrogen being used for the first time as a component of the complex of methodical solutions in the search practice. The research showed the importance of solving the problem of geo-ecological processes and accidents in mine workings and wells, connected to numerous disasters. According to numerous studies of mine massives, a set of preventive measures and criteria that prevent explosive processes was provided. The presence of a unique complex of natural components of hydrogen technology, solar and wind energy resources and fresh waters of the Danube lakes and the Danube was stated. The study emphasises the decisive role of Ukraine in the competition for primacy in scientific developments. For the first time in world practice, the implementation of global projects for the extraction and production of green and white hydrogen was substantiated. The technology was tested on numerous hydrocarbon deposits, water resources and mine workings and therefore has all the prospects for the effective application in the search and extraction of hydrogen. This monograph can be useful and informative for specialists in the fields of oil and gas geology, general and regional geology, hydrology, environmental protection, as well as for the students and postgraduate students of fuel and energy, oil and gas geological and hydrological areas, as well as for domestic and foreign investors.
Niche evolution versus niche conservatism and habitat loss determine persistence and extirpation in late Neogene European Fagaceae
No full textAn increasing body of palaeobotanical data demonstrates a series of Pliocene and Pleistocene extirpationsand extinctions of plant lineages in western Eurasia, which are believed to have been determinedby the climatic properties of their related East Asian and North American sister lineages.We investigatedthe diversity of a widespread northern hemispheric plant family, Fagaceae, during the Late Pliocene ofPortugal. We found a high diversity of Fagaceae comprising extant and extinct lineages. Dispersed pollenof 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 theNorth American clade of sect. Quercus are the youngest records of these modern New World groups inwestern Eurasia. For the extinct Trigonobalanopsis, the pollen record of Portugal is the youngest known ofthis genus. Climate data of modern representatives demonstrate that a deterministic model can explainonly a part of the Pliocene and Pleistocene extirpations. Modern cold month mean temperatures ofCastanopsis and Quercus sect. Cyclobalanopsis and their last occurrences in western Eurasia in the Pliocenefit with a deterministic model (niche conservatism). In contrast, survival or extirpation of groupswith high cold tolerance appear to have been more complex. Here, niche evolution, abundance anddiversity of a lineage during pre-Pleistocene times, and habitat availability/loss determined the fate ofFagaceae lineages in western Eurasia
Integrative taxonomy reveals unrecognised species diversity in African Corypha larks (Aves: Alaudidae)
No full textIntegrative taxonomy reveals unrecognised species diversity in African Corypha larks (Aves: Alaudidae)
No full textThe species complex comprising the rufous-naped lark Corypha africana, Sharpe’s lark Corypha sharpii, the red-winged lark Corypha hypermetra, the Somali long-billed lark Corypha somalica and Ash’s lark Corypha ashi encompasses 31 recognised taxa across sub-Saharan Africa, many of which are extremely poorly known and some not observed for decades. Only 17 taxa have been studied molecularly and none comprehensively for morphology, vocalisations or other behaviours. Here, we undertake comprehensive integrative taxonomic analyses based on plumage and morphometrics (for 97% of the taxa), mitochondrial and nuclear loci (77%), ≤ 1.3 million genome-wide single nucleotide polymorphisms (68%), song (many described for the first time; 52%) and additional behavioural data (45%). All polytypic species as presently circumscribed are paraphyletic, with eight primary clades separated by ≤ 6.3–6.8 Myr, broadly supported by plumage, morphometrics, song and other behaviours. The most recent divergences concern sympatric taxon pairs usually treated as separate species, whereas the divergence of all clades including C. africana subspecies is as old as sister species pairs in other lark genera. We propose the recognition of nine instead of five species, while C. ashi is synonymised with C. somalica rochei as C. s. ashi. The geographical distributions are incompletely known, and although the nine species are generally para-/allopatric, some might be sympatric