Hasil untuk "Paleontology"

Carla Arias, Benjamin Van Wyk de Vries, Rigoberto Aguilar et al.

Arequipa, often referred to as “White City, land of volcanoes,” is located in Southern Peru and is a designated UNESCO World Heritage Site. Its amazing landscape is framed by three imposing volcanoes: Chachani, Misti, and Pichu Pichu, reflecting a rich volcanic history evident in several geological sites both within and around the city. A total of 12 pilot geosites related to Chachani and Misti volcanoes, as well as Yura monogenetic field, have been inventoried and assessed. These encompass a range of volcanic deposits, structures, and scenic viewpoints, and have been classified based on their scientific, educational, and touristic value. The selection of these geosites was based on multiple criteria to ensure objectivity, prioritizing those that are the most representative, unique, in good conservation status, and of great scientific importance. Additionally, degradation risks have been evaluated to implement appropriate geoconservation measures and address potential threats according to their urgency. The assessment has followed a holistic methodology, inspired by successful models from previous studies, and recommendations have been made for developing an integrated management plan. The next step is to prepare the geosites for public use by developing geo-routes that highlight the volcanic geoheritage, while also integrating Arequipa's historical and cultural legacy. These geosites play a crucial role in geoeducation, raising awareness about volcanology and volcanic hazards. Moreover, the development of geotourism as a sustainable natural resource not only brings socioeconomic benefits to the local population but also fosters a deeper connection and identity with the territory. This enhanced sense of belonging strengthens community resilience to geological hazards, enabling better preparedness and adaptive strategies in the face of potential risks.

DENG Tao

Prof. Qiu Zhanxiang’s academic life presents a cross regional scientific research landscape: born in Qingdao City on the coast of the Yellow Sea, he devoted his life to exploring the mysteries of terrestrial mammalian evolution. In his early years, he received systematic training at the Geological Department of Moscow University and graduated in 1960, which laid a solid disciplinary foundation for him. After returning to China, he took root in the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, starting a scientific research journey that lasted for more than half a century. As a paleontologist, his career has distinct international characteristics: from 1982 to 1984, he was awarded the Humboldt Scholarship from the Federal Republic of Germany and completed his doctoral thesis at the Gutenberg University of Mainz, and from 1982 to 1999, he conducted a series of international cooperation projects. His academic leadership was particularly prominent in his career, as he led multiple strategic scientific research projects during his tenure at the institute from 1991 to 1995. His scientific research footprint spans from the Nei Mongol Gobi to the Tibetan Plateau, and from the Yushe Basin in Shanxi Province to the Linxia Basin in Gansu Province. The National Climbing Plan of “Research on the origin of early human beings and environmental background” presided over by him has created a new paradigm of interdisciplinary research. In terms of disciplinary achievements, Prof. Qiu has achieved three landmark accomplishments: deciphering the evolutionary code of the Paleocene red bed mammalian fauna of South China, clarifying the lineage of giant rhino fossils, and establishing a biochronological scale for the Neogene terrestrial strata in China and conducting in-depth research on the carnivore and perissodactyl fossils contained therein. These achievements have provided a key evidence chain for analyzing the evolutionary mechanism of mammals’ adaptation to environmental changes over 66 million years, which not only won him the title of CAS Academician in 2005, but also left China’s mark in the field of international Cenozoic paleontology and stratigraphy.

Tao Yang, Jia-Hao Cai, Yan-Zhi Dai et al.

Understanding the paleoenvironment and phytogeographical history of the Tibetan Plateau, China relies on discovering new plant fossils. The Qaidam Basin has long been regarded as an ideal ‘field laboratory’ to investigate the paleoclimate and paleobiological evolution of the northern Tibetan Plateau. However, fossil angiosperms from the Qaidam Basin are rare, and our knowledge of its paleovegetation is poor. Here, we report fossil leaves and fruits of Betulaceae found from the Oligocene Shangganchaigou Formation of northwestern Qaidam Basin (Huatugou area). Comparative morphological analysis led us to assign the fruits to the Betula subgenus Betula and the leaves to Carpinus grandis. These findings, together with other reported fossil plants from the same locality, reveal a close floristic linkage between the Qaidam Basin and Europe during the Oligocene. The northern pathway of this floristic exchange may have crossed through the Qaidam Basin during the late Paleogene. This floristic linkage may have been facilitated by the continuous narrowing of the Turgai Strait and stronger westerlies, which transported moisture and provided favorable climatic conditions. Indeed, fossil plants collected from the Qaidam Basin suggest that during the Oligocene this region had warm and humid deciduous broad-leaf forest, which differs from the region’s modern vegetation and indicates that the Qaidam Basin may have been a suitable region for these plants to flourish and spread during the Oligocene.

Alvard Muradyan, Alla Hayrapetyan, Marieta Asatryan et al.

Crocus L. (Iridaceae) is systematically a very problematic genus due to the lack of clear distinctive features, wide range of habitats and the heterogeneity of morphological features. This genus is also highly heterogeneous from a karyological point of view. Apart from the most common spiraperturate pollen grains in Crocus, the authors frequently mentioned a number of other aperture types for individual species (subspecies, variations, etc.), i.e. polyrugoidate, nonaperturate (inaperturate), polyaperturate, with more or less extensive furrows, with short furrows, etc. The purpose of this work is to perform a palyno-morphological analysis of pollen aperture types noted in the genus Crocus. The reason for the study is a significant disagreement among researchers when describing the types of pollen apertures in the genus Crocus. An analysis of the literature, as well as the results of our previous studies, showed that the genus Crocus is characterized by inaperturate (nonaperturate), polyaperturoidate, spiraperturate and net-like pollen apertures. The similar net-like apertures were observed for some representatives of the subgenus Scorpiris Sach of the genus Iris L., in particular, in Iris atropatana Grossh. In our opinion, this aperture type can serve as a link between the genus Crocus and the subgenus Scorpiris of the genus Iris. We suggest, that the spiraperturate pollen type mentioned most often for the representatives of the genus Crocus can be considered the basic type within the genus. On the other hand, formless aperture-like areas are genetically unstable transitory variations, which occurred arbitrarily due to mutations. Finally, “polyrugoidate” (or with net-like apertures) pollen type noted in the literature for C. chrysanthus subsp. punctatus F.Candan et N.Özhatay may be considered to be more advanced in the genus Crocus

Elena A. Jagt-Yazykova, Martin Košťák, John W. M. Jagt

Abstract A newly collected specimen of the enigmatic coleoid genus Longibelus is recorded from lower Turonian strata along the River Shadrinka in Sakhalin (Russian Far East). To date, this is the first record of Late Cretaceous coleoid cephalopods from the island and, in fact, from the entire Pacific coast of the Russian Federation. Lithological characteristics, coupled with published geochemical analyses (δ13C and Corg content), suggest the habitat of this coleoid taxon to have been the middle to outer (i.e. distal) shelf. Its provenance from the stratigraphical level that is known as the Scaphites Event, characterised by a mass occurrence of Scaphites and Yesoites, may be indicative of occasional or marginal overlap in ranges, rather than life in similar habitats. On the basis of lithological features and in view of the extremely rare occurrence of Longibelus in rich ammonite assemblages with clear ecological/bathymetric preferences, the natural habitat of Longibelus may have comprised neritic to mesopelagic zones over distal shelves and slopes.

Fereshteh M. Haskouei, Habib Alimohammadian, Jafar Sabouri

Las técnicas de magnetismo ambiental nos permiten reconstruir las condiciones del paleoclima para obtener resultados como las pérdidas. Las propiedades magnéticas de los minerales se utilizan como sustitutos de los cambios ambientales. En este estudio se investigó la secuencia magnética de loess-paleosol de la sección de Kolet en Neka, al noreste de Irán. Fueron aplicados métodos de magnetismo ambiental para reconstruir los cambios del paleoclima. Se investigó la relación entre los cambios del paleoclima y los proxies del magnetismo ambiental como la variación de la susceptibilidad magnética (χ). Las técnicas de laboratorio indicaron la presencia del factor principal de propiedad magnética en la secuencia de loess-paleosol, como magnetita, maghemita, etc. También, se estimó magnéticamente parámetros (como SIRM, HIRM, etc.) para confirmar concentraciones de partículas tanto eólicas como pedogénicas frente a variaciones de la mejora de la susceptibilidad magnética. Los valores de χ muestran picos prominentes para los tres horizontes de suelos y paleosuelos bien desarrollados, Suelo reciente (S0 por sus siglas en inglés), Paleosol superior (S1, por sus siglas en inglés) y Paleosol inferior (S2, por sus siglas en inglés); que se refieren a condiciones más cálidas y húmedas. Como resultado se obtuvo que el aumento/disminución de la susceptibilidad magnética coincide con la secuencia paleosol-loess, y probablemente con condiciones húmedas/áridas. Además, las variaciones de la susceptibilidad magnética versus la columna litológica de la sección de Kolet permitieron reconocer períodos paleoclimáticos conocidos como ciclos interglaciares/glaciales. Se trazó la variación de la susceptibilidad magnética (MS, por sus siglás en inglés), la magnetización del remanente natural (NRM, por sus siglás en inglés), la susceptibilidad dependiente de la frecuencia (χfd) y de χfd% versus la gráfica litológica del perfil de loess para confirmar que los depósitos de loess/paleosol de la sección de Kolet tienen partículas magnéticas. Luego, aplicamos los datos magnéticos obtenidos como variación de susceptibilidad magnética (MS, por sus siglás en inglés) para indicar que ha habido períodos glaciales/interglaciares durante los últimos 50 ka. Por lo tanto, durante este período de tiempo, hay tres ocurrencias glaciares importantes en el área de estudio. Además, concluimos que no hubo ocurrencia de glaciaciones principales desde los últimos 20.5 ka. doi: https://doi.org/10.22201/igeof.00167169p.2021.60.4.1949

Ya Li, Yi-Ming Cui, Carole T. Gee et al.

Abstract Background Although Trapa is a well-defined genus of distinctive freshwater plants with accumulations of extensive morphological and embryological autapomorphies, its phylogenetic relationships have long been unclear. Formerly placed in the monotypic family Trapaceae, Trapa is now recognized as sister to Sonneratia within Lythraceae s.l., although both genera lack morphological synapomorphies. Thus, a split between the two taxa must have occurred in deep evolutionary time, which raises the possibility of finding transitional forms in the fossil record. Results Here we describe a new genus and species, Primotrapa weichangensis Y. Li et C.-S. Li (Lythraceae s.l.: Trapoideae), based on three-dimensionally preserved floral cups, fruits, and seeds from the early Miocene of Weichang County, Hebei Province, China. Primotrapa is characterized by a shallow, saucer-shaped floral cup, four distally barbellate sepals, four intersepal appendages alternating with the sepals at the rim of cup, a superior to basally inferior ovary, a fusiform or ovoid, one-seeded fruit with a ribbed surface, and a long persistent peduncle. Two fossil species of Hemitrapa are proposed as new combinations of Primotrapa, namely P. alpina (T. Su et Z.-K. Zhou) Y. Li et C.-S. Li comb. nov. and P. pomelii (Boulay) Y. Li et C.-S. Li comb. nov. Our phylogenetic analysis based on fifteen flower and fruit characters supports the placement of Primotrapa, Hemitrapa and Trapa in a monophyletic clade, which comprise subfamily Trapoideae. The phylogenetic analysis places Primotrapa at the base of Trapoideae. Conclusions In view of its superior ovary, which is a plesiomorphic character of Lythraceae s.l., the newly recognized genus Primotrapa and its three species likely represent transitional forms that bridge the evolutionary gap between the basal taxa of Lythraceae s.l., i.e. Lythrum, and the highly derived taxon Trapa.

Zi-Kun Jiang, Yong-Dong Wang, Ning Tian et al.

Abstract Western Liaoning is a unique region in China that bears diverse types of Jurassic plants, including leaves, fern rhizomes, and wood, providing significant proxy for vegetation and palaeoenvironment reconstruction of the well-known Yanliao Flora in East Asia. In particular, the silicified wood is very abundant in the fossil Lagerstätte of the Jurassic Tiaojishan Formation in Beipiao, western Liaoning. Previous and recent systematic investigations documented a high diversity of the Jurassic wood assemblages. These assemblages are dominated by conifers, followed by cycads and ginkgoaleans. In total, about 30 species belonging to 21 genera of fossil wood have been recorded so far, which are represented by Cycadopsida, Ginkgopsida, Coniferopsida, and Gymnospermae incertae sedis. The evolutionary implications of several distinctive fossil wood taxa as well as palaeoclimate implications are summarized based on their anatomical structures and growth ring patterns. This work approaches the vegetation development and evolutionary significances of the wood taxa and their relatives, and provides clues for the further understanding of the diversity of the Jurassic Yanliao Flora in East Asia.

Yu. O. Semenov

The history of the discovery, studying and disappearance of Grebeniki, a locality of bone remains of late Miocene vertebrates is presented. This paleontological object had been developing for more than 60 years and it is one of the most known and richest in Europe by the number of fossil records and their well-preserved state, and the taxonomic diversity of extinct fauna. Grebeniki is the type locality of the Grebeniki Paleofaunal Subassemblage. Due to its value, it was included into the Nature Reserve Fund of Ukraine as a Geological Nature Monument of the same name in the Odesa region. The disappearance of this locality in the late 1970s was not because of human activity, but the influence of natural factors. Quite possibly, it has not disappeared forever and might be revealed again through the same erosion processes that buried it.

Martin Košt'ák, Andrej Ruman, Ján Schlögl et al.

Two sepiid genera, Notosepia Chapman, 1915, andSepia Linnaeus, 1758, are described from the Neogene deposits ofAustralia. A new and unique record of the middle Miocene Sepia sp.is reported from southern Australia. Based on similarities to contemporaneoussepiids, the new sepiid cuttlebonedescribed herein belongs to the genus Sepia. Notosepiacliftonensis is suggested herein to be a descendant of the archaeosepiidstem lineage. Microstructures (lamella-fibrillar nacre is the nacre Type II ofsepta and pillar prismatic layers) of the excellently preserved cuttlebone ofSepia sp. display a modern character of the phragmocone, fullycomparable to the recent taxa. The stratigraphically well-calibrated (basedon foraminifera) cuttlebone represents the first unambiguous fossil record ofthe genus Sepia from the Southern Hemisphere. It significantlyextends the biogeographical distribution of modern sepiids in the Miocene andsuggests the existence of a sepiid eastward migratory route. Moreover, thepresence of both conservative- and modern-type cuttlebones suggests a dualcolonisation of Australian waters: the first (archaeosepiid) during the lateEocene–late Oligocene and the second (sepiid) during the early Miocene.

John H. Acorn, Elizabeth Martin-Silverstone, James R.N. Glasier et al.

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Stiliani Fragouli, Αggeliki Rokka, Apostolia Galani

In this study we introduce teaching proposals to “inject” ammonite fossils, in the Geography syllabus, as evidence of Greek paleoenvironment, which at the moment is the only existing geoscience subject of Greek primary curriculum. Paleontology and mainly fossils attract more and more elementary students and teachers. Unfortunately, in Greece, this trend solely concerns about dinosaurs, despite the fact that the most common Greek fossils are not dinosaurs, but ammonites. Ammonites can be found in large population and diversity inside Greek rocks, as these rocks were part of Tethys΄ seafloor at their geological time. Apart from the informal sources of education, these geoscience/physical geography topics are excluded from elementary national curriculum, thus leaving out the regional paleogeography and geological history practically “unknown” to students and future citizens of our region. Data collected through a pre-test study among the 5 th and 6th grade students confirmed the above belief. A post-test at the original sample, using an open ended questionnaire and students’ drawings, evaluated positively the teaching proposals designed.

N. A. Haag, M. Henriques

Eugenio Sanz, Antonio Arcos, Carlos Pascual et al.

This paper reports the use of FEA (Finite Element Analysis) to model dinosaur tracks. Satisfactory reproductions of sauropod ichnites were simulated using 3D numerical models of the elasto-plastic behaviour of soils. Though the modelling was done of ichnites in situ at the Miraflores I tracksite (Soria, Spain), the methodology could be applied to other tracksites to improve their ichnological interpretation and better understand how the type and state of the trodden sediment at the moment the track is created is a fundamental determinant of the morphology of the ichnite. The results obtained explain why the initial and commonly adopted hypothesis—that soft sediments become progressively more rigid and resistant at depth—is not appropriate at this tracksite. We explain why it is essential to consider a more rigid superficial layer (caused by desiccation) overlying a softer layer that is extruded to form a displacement rim. Adult sauropods left trackways behind them. These tracks could be filled up with water due to phreatic level was close to the ground surface. The simulation provides us with a means to explain the differences between similar tracks (of different depths; with or without displacement rims) in the various stratigraphic layers of the tracksite and to explain why temporary and variable conditions of humidity lead to these differences in the tracks. The simulations also demonstrate that track depth alone is insufficient to differentiate true tracks from undertracks and that other discrimination criteria need to be taken into account. The scarcity of baby sauropod tracks is explained because they are shallow and easily eroded.

J. Botelho, L. Ossa-Fuentes, S. Soto-Acuña et al.

A new study that integrates developmental and paleontological data reveals previously unsuspected evolutionary transformations during the emergence of the bird wrist, consistent with its derivation from non-avian dinosaurs.

Soichiro Kawabe, Seiji Matsuda, Naoki Tsunekawa et al.

[This corrects the article DOI: 10.1371/journal.pone.0129939.].

Ana M. Parras, Silvio Casadío, Mónica Pires

The sequence stratigraphic analysis of the Malargüe Group in the south of Mendoza Province, allows the recognition of five depositional sequences. The first sequence is attributed to a river-dominated delta and lake setting and the second to a river-dominated delta transitional to a tide-dominated delta (continental to marginal marine facies); both are assigned to the Loncoche Formation. The third sequence was deposited in a subtidal to intertidal environment; it contains Maastrichtian fossils and is referred to the Roca Formation. The fourth sequence is attributed to lacustrine and fluvial environments, and the fifth is indicative of fluvial conditions; both are assigned to the Pircala Formation. The paleontological evidence and two 40K-40Ar radiometric ages indicate that, in this area of the basin, the Cretaceous-Paleogene boundary lies in the continental deposits of Pircala Formation (depositional sequence IV). From this, we conclude that at the beginning of the Danian, the northern boundary of the "Rocanense Sea" lie south of 36° S. KEY WORDS. Sequence stratigraphy. Cretaceous-Paleogene boundary. Malargüe Group. Mendoza Province. Argentina.

A. Altenbach, J. Bernhard, J. Seckbach

Wu Genyao

The important event in Jurassic tectonics in Mongolia was the subduction and closure of the Mongolia-Okhotsk ocean; correspondingly, basin evolution can be divided into two main stages, related to the orogeny and collapse of the orogenic belt, respectively. The developing of Early–Middle Jurassic basins to the north of the ocean resulted from back-arc extension. The fossil sutures, from the China–SE Asia sub-continent to the south of the ocean, were rejuvenated by subduction-related orogeny; in addition, the Yanshanian intra-continental movement occurred. Three Early–Middle Jurassic molasse basins were developed by movement in Inner Mongolia, all of which stretched westwards (or northwards) into Mongolia; therefore, the molasse basins in eastern and southern Mongolia had the same geometric and kinematic features as the basins in the Inner Mongolia. Owing to the collapse of the Mongolia-Okhotsk orogenic belt, a group of rift basins developed during the Late Jurassic. In eastern Mongolia, the NE orientated extensional basins were controlled by the neogenic NE-structure. The contemporary basins in southern Mongolia and the neighboring areas in China were constrained by remobilization (inherited activation) of the latitudinal or ENE-directional basement structures. Three stages can be recognized in the evolution of the Early–Middle Jurassic basins after reversal; the basins also experienced four episodes of reformation.

Paula Bona

Los Alligatoridae del Mioceno Tardío de Argentina: el registro más austral de cocodrilos neógenos en América del Sur