Luis Sebastián Agüero, Daniela Elizabeth Olivera, Marcelo Adrián Martínez
et al.
This contribution integrates palynofacies, organic geochemical and sedimentological analyses to characterize the depositional environment and the kerogen properties related to the hydrocarbon source potential of the Vaca Muerta Formation at the Mallín Quemado Norte (MQN) and Puerta Curaco (PC), Neuquén Basin, Argentina. Thirty-five outcrop samples were analyzed for palynofacies and total organic carbon (TOC). At MQN, five palynofacies types and sedimentological evidence suggest deposition mainly in an outer shelf marine environment with a variable continental input. At PC, three palynofacies types and sedimentological observations point to accumulation mainly in an outer ramp marine environment with minimal to moderate terrigenous input. Depositional processes involve an interplay of suspension settling from the water column (marine snow) and buoyant plumes, followed by reworking of the seafloor by bottom currents and sediment gravity flows. Under identical hydrodynamic flow conditions, equidimensional phytoclasts respond better to transport sorting than blade-shaped. The first documentation of high-relief organic spheres (HROS) in this unit points to redox oscillation between sulfidic and ferruginous anoxic microenvironments during early diagenesis. Low HROS percentages and crypto-bioturbated strata suggest that bottom waters were not strictly anoxic. Organic carbon preservation may be partly related to the role of extracellular polymeric substances as an organic matter encapsulator. The kerogen aligns with type III-IV, and TOC values are mainly high (MQN: up to 4.69%; PC: 4.9–10.4%). Although an over-mature state cannot be entirely ruled out (highly dark palynological matter), the poor preservation of the kerogen suggests a negligible hydrocarbon potential.
ALFIO MOSCARELLA, MARCO ROMANO, LORENZO CONSORTI
et al.
During the sampling of a stratigraphic section along the shore of the Fiastra Lake (Carg Project - Sheet 313 “Camerino” of the Geological Map of Italy at 1:50 000 scale), a small rock boulder with partially exposed bony material was discovered at the base of a small cliff at the northern termination of the Sibillini Mts. In this area, the classical facies of Umbria-Marche stratigraphic succession are well exposed. The Oligocene-Miocene portion of the succession is represented by the ~200 m-thick Scaglia Cinerea Formation, passing upwards to the ~100 m-thick Bisciaro Formation. The microfossil assemblage has allowed the specimen to be constrained to the lower Burdigalian. The skeletal remains were examined using a CT-SCAN, a non-invasive method that has proven to be highly performing. The analysis revealed some articulated vertebrae, deformed by lithostatic compaction, which are attributed to a shark of the Order Lamniformes. Subsequently, the vertebrae were digitally isolated, extracted from the surrounding matrix, and rendered into three-dimensional prints. Through digital retro-deformation, the body length of the lamniform shark was estimated to be approximately 4 metres. Further considerations on the vertebrae allowed us to infer that the studied shark had similarities to either Isurus oxyrinchus Rafinesque, 1810 or Carcharodon carcharias Linnaeus, 1758. The development of a dead-fall microbial community likely facilitated the preservation of the vertebrae. The studied specimen represents the first occurrence of a lamniform shark in the Lower Miocene of the Umbria-Marche Domain and represents one of the very rare recorded occurrences of lamniforms from the Lower Miocene of Italy.
A magnetostratigraphic study on four sections near Pinjor showed that the Tatrot stage falls in the Gauss magnetic epoch and the Pinjor corresponds to most of the Matuyama epoch. A significant faunal change, already observed by other authors in Pakistan, marks the Tatrot-Pinjor boundary and approximately coincides with the Gauss-Matuyama transition. Sedimentation becomes entirely conglomeratic in a positive episode tentatively interpreted as Jaramillo. The time interval represented by this event witnessed a deep climatic change in Europa and an extensive faunal turnover in all Eurasia, and seems also to correspond to the onset of a strong tectonic activity in the Himalayan belt.
Além das pesquisas e aulas que ministrava em anatomia comparada, fisiologia, história natural e paleontologia, Thomas Henry Huxley (1825-1895) dedicou muito do seu tempo a dar palestras públicas. Estas, foram publicadas posteriormente como ensaios, contribuindo assim, para a difusão de suas ideias. Este artigo consiste em uma tradução de um desses ensaios “The rise and progress of paleontology” (O surgimento e a ascensão da paleontologia), em seu livro Collected essays: Science and the Hebrew em 1894. Neste trabalho Huxley apresentou à sua audiência um breve resumo sobre como a paleontologia surgiu, suas escolas, suas perspectivas e como a paleontologia se encaixava no contexto científico geral de sua época. Ele utilizou uma linguagem compreensível e convincente. Esperamos que este trabalho possa contribuir para o conhecimento das ideias paleontológicas de Huxley.
Biology (General), Epistemology. Theory of knowledge
We collected contemporary foraminiferal training sets from two salt marshes to enable more precise and accurate proxy historical sea-level reconstructions from southeastern Australia. Combined with an existing training set from Tasmania, this new regional set consists of 112 samples and 16 species of foraminifera, of which 13 are agglutinated. Cluster analyses group the regional training set into a high–elevation cluster, dominated by 'Trochamminita salsa', a mid–elevation cluster, dominated by 'Entzia macrescens' and 'Trochammina inflata', and a mid–low elevation cluster dominated by Miliammina fusca and tidal-flat species. We develop transfer functions using local and regional training sets and assess their performance. Our resulting site-specific and chosen regional models are capable of predicting sea level with decimetre-scale precision (95% confidence intervals of 0.12–0.22 m). These results are comparable to other examples from around the world. When developing regional training sets, we advocate that the similarity in the environmental settings (particularly salinity) should be assessed as an alternative way of grouping sites, rather than simply using spatial proximity. We compare our findings with global results and conclude that salt marshes along microtidal coasts yield models with the lowest vertical uncertainties. Studies with the lowest uncertainties are located in the western Pacific and the western Atlantic, whereas those from the eastern Atlantic generally have larger tidal ranges and carry larger vertical uncertainties. Our models expand the existing region available for sea-level reconstruction and can be used to generate new late Holocene sea-level reconstructions across southeastern Australia.
Andrea Baucon, Carlos Neto de Carvalho, Antonino Briguglio
et al.
Ichnofossils, the fossilized products of life-substrate interactions, are among the most abundant biosignatures on Earth and therefore they may provide scientific evidence of potential life that may have existed on Mars. Ichnofossils offer unique advantages in the search for extraterrestrial life, including the fact that they are resilient to processes that obliterate other evidence for past life, such as body fossils, as well as chemical and isotopic biosignatures. The goal of this paper is evaluating the suitability of the Mars 2020 Landing Site for ichnofossils. To this goal, we apply palaeontological predictive modelling, a technique used to forecast the location of fossil sites in uninvestigated areas on Earth. Accordingly, a geographic information system (GIS) of the landing site is developed. Each layer of the GIS maps the suitability for one or more ichnofossil types (bioturbation, bioerosion, biostratification structures) based on an assessment of a single attribute (suitability factor) of the Martian environment. Suitability criteria have been selected among the environmental attributes that control ichnofossil abundance and preservation in 18 reference sites on Earth. The goal of this research is delivered through three predictive maps showing which areas of the Mars 2020 Landing Site are more likely to preserve potential ichnofossils. On the basis of these maps, an ichnological strategy for the Perseverance rover is identified, indicating (1) 10 sites on Mars with high suitability for bioturbation, bioerosion and biostratification ichnofossils, (2) the ichnofossil types, if any, that are more likely to be present at each site, (3) the most efficient observation strategy for detecting eventual ichnofossils. The predictive maps and the ichnological strategy can be easily integrated in the existing plans for the exploration of the Jezero crater, realizing benefits in life-search efficiency and cost-reduction.
The Yushe Basin (Shanxi, China) represent one of the most renowned location of China for Uppest Miocene-Lower Pleistocene fossiliferous beds, with an outstanding record of vertebrates, often reference to other Asian localities. Fossils from the town of Xiakou are considered among the oldest records (late Gaozhuang-earliest Mazegouan) of Eucyon davisi in the Basin. Nevertheless, the study of some Early Pliocene specimens of this sample attributed to E. davisi possess several features typical of Vulpes. The revision of this material in comparison with that of other fossil fox species from Asia revealed the peculiarity of the Vulpes from Xiakou, both metrically and morphologically, leading to the description of a new species, Vulpes rooki sp. nov. Dental features and proportions suggest that this large-sized fox had probably a hypercarnivorous diet, unlike the similar-sized E. davisi. Following other results in literature, the considerably diverse fossil record of canids in the Yushe Basin supports the interpretation of niche partitioning among these species during the Early Pliocene.
David S Berman, Stuart S. Sumida, Stuart S. Sumida
et al.
A comprehensive description of the holotype skeleton is presented here for the first time of the lower Permian (Artinskian) reptile Eudibamus cursoris from the Bromacker locality of Germany since the brief description of the holotype in 2000. The holotype is essentially complete and is the only known bolosaurid represented by a well-preserved articulated skeleton. Included in the description here is a superbly preserved, partial, articulated second specimen of E. cursoris discovered at the same locality that includes a short portion of the vertebral column associated with the pelvis and right hindlimb. Descriptions of the holotype and new specimen add substantially to features of the skull and postcranium that not only confirm a bolosaurid assignment, but also add significantly to an already long list of structural features supporting an ability unique among Paleozoic vertebrates to reach relatively high bipedal and quadrupedal running speeds employing a parasagittal stride and digitigrade stance with the limbs held in a near vertical posture. Structural differences between the two specimens are restricted to the tarsi and are attributed to different ontogenetic stages of ossification, with the holotype representing a more juvenile individual, and the larger second specimen representing a more mature animal.
Nineteenth Century novelists frequently picture life beyond and across the edges of humanity—figuratively moving the ‘posts’ of humanity—a practice that this article calls ‘posthumanisation’. Inspired by the accelerating as well as mutually reinforcing dynamics of colonial expansion, empiricism, new biological and scientific findings (Darwin, paleontology, and psychology), and the rise of industrialisation, prominent writers such as Mary Shelley, the Brontë sisters, and Joseph Conrad habitually blur human-animal boundaries. This article engages with versions of posthumanisation in selected novels by these authors—Mary Shelley’s Frankenstein (1818), Charlotte Brontë’s Jane Eyre (1847), and Joseph Conrad’s Heart of Darkness (1898)—and the anonymously published The Woman of Colour (1808), examining how they engage either in critiquing the perfidious overlaps between posthumanisation and colonial discourse (The Woman of Colour; Frankenstein) or blur Cartesian binaries between humans and animals to reinforce colonialism’s narcissistic politics of non-relation (for example, seeGandhi, 2006;Simmons, 2007; andDrichel, 2018). The article foregrounds the extent to which a thriving colonial discourse and biological racism do not (necessarily) result in a ‘fixing’ of racial others on the side of ‘animal’ (and, as such, in their ‘dehumanisation’), but rather in a strategic ‘flexibilisation’ of ‘hum-animality’ (seeEllis, 2018) in the interest of plausibilising white supremacy and the slavery system. Arguing for the merit of historicizing literary analysis as posthumanist scholarship directs its gaze to the past; building on race-critical contributions to posthumanist discourse (see, for example,Malm and Hornborg, 2014;Jackson, 2015;Jackson, 2020;Davis et al., 2019; and Yussof, 2019); and also engaging with the still-scarce scholarship on the overlaps of posthuman being and race relations in the context of Britain’s ‘imperial century’ (seeEllis, 2018; andJackson, 2020), this essay contributes to setting on a more solid, historical foundation a discourse that has repeatedly been criticised for engaging a ‘racial’ ‘wilful blindness’ (Yusoff, 2018). The article thus contributes to diversifying not only historical approaches to ‘proto-posthumanisms’ as they are currently proliferating in the field but also, and by implication, current posthumanist self-understandings and research ethics.
History of scholarship and learning. The humanities
Alan R. Lord, M. Cristina Cabral, Dan L. Danielopol
Sieve-type normal pore canals (StPC) occur commonly in living and fossil cytheroid ostracods but their biological function(s) and evolutionary history are poorly known. The new genus Minyocythere and its four species: Minyocythere macroporosa sp. nov., M. angulata sp. nov., M. maculosa, and M. tuberculata from the Middle Jurassic have StPC prominently developed, display a range of normal pore canals, and provide a context for review of the geological record and palaeobiological potential of these structures, and their application as a taxonomic tool compared with classical approaches. The related Cretaceous genus Dolocythere is reviewed and Dolocythere amphistiela sp. nov. described. The significance of StPC for comparative morphology, systematics, palaeobiology and environmental interpretation are discussed. The range of normal pore canals observed, including StPC, is greater than previously described and several types can occur on one animal implying different life functions. The potential of normal pore canals especially StPC for systematic use is established although good preservation is essential. The functional significance of normal pore canals and their setae must be verified with living material before their evolutionary history can be deduced and their application to palaeoenvironmental interpretation and modern environmental monitoring enhanced.
Detailed distribution ranges of the genus Ericsonia were obtained in the upper Paleocene interval from two deep-sea sections, ODP Site 1262 (South Eastern Atlantic Ocean) and Site 1215 (Eastern Equatorial Pacific Ocean), and were complemented with morphometric analyses with the purpose of clarifying the taxonomy of the Paleocene species ascribed to genus. The analysis on a high-resolution sampling set at ODP Site 1262 permitted to add information about the evolutionary relationship among the taxa included in the Ericsonia lineage, whose evolutionary emergence characterize the Paleocene nannofossil assemblages. Two taxonomic units have been validated in the Paleocene, Ericsonia subpertusa and Ericsonia robusta and they turned out to not have any evolutionary link. E. robusta shows substantial morphologic variability at cross-polarized light resulting in two endmember morphotypes, E. robusta morphotype A and E. robusta morphotype B. When observed at S.E.M., the two morphotypes have placoliths with a similar structure, therefore they document intra-specific variability. This is corroborated by the presence of specimens with intermediate morphologic features between the two endmembers, throughout the distribution range. E. robusta increases in abundance concomitantly with the sharp decline of E. subpertusa in mid Chron C25n. Subsequently, the highest occurrence of E. robusta morphotype B provides a distinct biohorizon coeval to the general decline of E. robusta within the upper Paleocene nannofossil assemblage.
Within the framework of reinterpretation of the depositional evolution of the Komjatice depression, presence of cummingtonite in weakly lithified sediment has been detected. The sediment is formed by volcanic lithoclasts and phenocrysts with a small admixture of non-volcanic grains. The different mineral composition and various degrees of alteration of volcanic lithoclasts, together with structural features point to epiclastic origin. Therefore, the studied samples can be described as volcanic paraconglomerate and sandstone. The cummingtonite is found in rusty coloured volcanic lithoclasts and in the heavy fraction. Cummingtonite-bearing volcanic rocks have not been described so far from the Slovak Neogene volcanic fields. Therefore its presence in the studied samples represents the first indication of such volcanic rock in Slovakia. The aim of the article is to invoke interest for finding these volcanic rocks in situ.
Some larger foraminiferal assemblages (mostly nummulitids) near the Middle/Upper Eocene boundary have been investigated. Sections of the Veneto area (Berici and Lessini Mts., northern Italy) were studied and compared with others of the same age from Spain (Ebro basin) and Romania (Cluj-Napoca). In the Veneto area the results allow to split the upper Middle Eocene Nummulites brongniarti Zone into two biozones: a lower N. lyelli Zone and an upper N. biedai Zone. The N. aff. fahianìi Zone is here renamed N. variolarias/incrassatus Zone. This subdivision can also be recognized in Spain and Romania. According to the current conceptions, the base of the Priabonian (= Upper Eocene) could correspond either to the base of the N. fabianii s.s. Zone or to the base of the N. vaiolarius/ incrassatas Zone. Anyway, the Mossano succession could be a potential Globai Stratotype Section and Point for the base of the Priabonian.
Asphinctites tenuiplicatus [M] and Polysphinctites secundus [m] from the Asphinctites tenuiplicatus Zone (Early Bathonian), are usually considered as a sexual dimorphic pair, although authors describe them as separate species. We used statistical methods to test the sexual dimorphic correspondence between those morphospecies, based on a rather large sample of well-preserved macro- and microconchs derived from a single horizon of calcareous concretions in the Polish Jura. Our results indicate that both dimorphs or sexes have identical ontogeny up to a critical diameter, from which they diverge towards the characteristic morphology and sculpture of each dimorph. Thus, both dimorphs are described as a single species: Polysphinctites tenuiplicatus [M and m]. After review of the several nominal species usually assigned to the genera Asphinctites and Polysphinctites throughout their stratigraphic and biogeographic range in the Early Bathonian of the Tethys, it is concluded that they actually correspond to only two species of a single lineage. The corresponding name for the lineage should be Polysphinctites (= Asphinctites as a junior synonym).
Aaron R. H. LeBlanc, Amanpreet K Brar, William J May
et al.
Captorhinids were Paleozoic eureptiles that originated in the Late Pennsylvanian in Laurasia and dispersed across the major landmasses of Pangaea by the Late Permian. Their evolutionary success as omnivorous and herbivorous members of Permian terrestrial communities has been attributed to the evolution of multiple marginal tooth rows. Multiple tooth rows evolved at least twice within Captorhinidae: once in the omnivorous Captorhinus aguti and again in the diverse subfamily of herbivorous moradisaurines. The earliest known moradisaurines co-occured with C. aguti in Lower Permian strata of Texas; however C. aguti is also known from much older fissure fills in the famous Dolese Brothers quarry near Richards Spur, Oklahoma, suggesting that C. aguti preceded any other multiple-rowed captorhinid. Here we report on new material of multiple-rowed captorhinids from the Lower Permian fissure fills of the Bally Mountain locality in Oklahoma, only 35 miles from Richards Spur. Some of this material is referrable to Captorhinikos valensis, which was previously only known from younger strata in Texas, making this species the geologically and phylogenetically oldest moradisaurine. Furthermore, we determined that Ca. valensis co-existed with C. aguti at Bally Mountain and we explore the potential for niche partitioning in these early captorhinids. Lastly, we assess the potential temporal and environmental differences between Bally Mountain and Richards Spur, in order to explain the abundance of herbivorous moradisaurines at Bally Mountain and the complete lack of moradisaurines at the neighbouring Richards Spur locality.
Dating the Tree of Life (TOL) has become a major goal of biological research. Beyond the intrinsic interest of reconstructing the history of taxonomic diversification, time-calibrated trees (timetrees for short, as used throughout below) are required in many types of comparative analyses, where branch lengths are used to assess the conservation importance of lineages, correlation between characters, or to assess phylogenetic niche conservatism, among other uses. Improvements in dating the TOL would thus benefit large segments of the biological community, ranging from conservation biology and ecology through functional biology and paleontology. Recently, progress has been made on several fronts: in compiling databases and supertrees incorporating paleontological data, in computing confidence intervals on the true stratigraphic range of taxa, and in using birth-and-death processes to assess the probability distribution of the time of origin of specified taxa. Combined paleontological and molecular dating has also progressed through the insertion of extinct taxa into data matrices, which allows incorporation of their phylogenetic uncertainty into the dating analysis.
TAISSA RODRIGUES, ALEXANDER W. A. KELLNER, BRYN J. MADER
et al.
Although pterosaurs from Africa are still rare, in recent years several specimens have been described from the Kem Kem beds (Upper Cretaceous, Cenomanian) of Morocco. Here we describe four additional specimens from this informal lithostratigraphic unit: a jaw fragment, two mid-cervical vertebrae, and a humerus. All these specimens show three-dimensional preservation, differing much from the flat condition found in most pterosaur material. The vertebrae are particularly well preserved, and allow accurate observations on the pneumatization of the neural arch. Based on comparable material, we show that at least two edentulous pterosaur species were present in this informal lithostratigraphic unit, thus adding to the growing evidence of considerable pterosaur diversity in northwestern Africa during the "middle" Cretaceous. So far, the Kem Kem beds have the most diverse pterosaur fauna in this continent, with the presence of anhanguerids, azhdarchids, pteranodontids, and tapejarids.