Fossil Forms Research Articles

Radiolarians from Cambrian Series 2 Niujiaohe Formation in southern Jiangxi, South China

The origin and early evolution of radiolarian fossils have always provoked great interest among paleontologists. Yet, little is known about the earliest morphological and evolutionary characteristics of radiolarians largely due to the lack of documentation of early Cambrian radiolarian fossils. Herein, we conduct a thorough examination of the basinal Niujiaohe Formation in Chongyi County of southern Jiangxi and report two types of radiolarians: a large number of spherical radiolarians and a minor occurrence of ellipsoidal radiolarian fossils with bipolar rodded spines. The lengths of the spines on ellipsoid radiolarian fossils vary, and typically, the main spines are slightly offset from the polar axis, resulting in an asymmetrical appearance in some specimens. Through systematic taxonomic examination, this radiolarian fossil form is tentatively identified as Beothuka sp. of the spherical polycystine group. The genus Beothuka is commonly found in the Early Ordovician and has not yet been reported in the early Cambrian. Combined with previous reports, four species of radiolarians in three genera are identified from the Niujiaohe Formation in South China, including Paraantygopora porosa, Paraantygopora sp., spherical radiolarian, and Beothuka sp. Overall, the radiolarian fossils in the Niujiaohe Formation are characterized by low diversity and small size, in contrast to the relatively more diverse fauna found in the contemporary shallow-water Shuijingtuo Formation. Therefore, we speculate that radiolarians may have initially originated in shallow water areas and gradually expanded to deep water. This study further enriches the fossil record of the Cambrian Series 2 radiolarians. Combined with relevant data from South China, the radiolarian fauna began to exhibit diversity and complex morphology, indicating the presence of various, advanced spherical-skeletons in early radiolarians, and radiolarians from the early Cambrian appeared to display multiple evolutionary trends.

Revisione delle cipree (Mollusca, Cypraeoidea) mesozoiche italiane

The author presents the revision of the 17 specimens of Mesozoic cypraeids found in Italy, following the direct re-examination of the specimens, three of which are currently lost. The review led to the identification of only six formally valid species, belonging to four genera: (i) Palaeocypraea tithonica and (ii) Bernaya gemmellaroi, from the Tithonian of Termini Imerese and the Island of Capri; (iii), Bernaya apenninica (not Cypraea retusa, preoccupied name) from the Cenomanian of the Ocre Mountains; (iv) Cypraea pustulifera, from the Cenomanian of the Ocre Mountains; (v) Bernaya molisana sp. nov., from the Turonian-Senonian of the Matese. Furthermore, direct examination of the types allowed me to definitively establish that (vi) Bernaya (Protocypraea) striata, also from the Cenomanian of the Ocre Mountains, belongs to the genus Ovula. From a paleoecological and evolutionary point of view, it is confirmed that the first fossil forms of cowries date back to the Jurassic and began to diversify in the Cretaceous in the Mesozoic reef environment characterized by high energy, thanks precisely to the tiny dimensions, as well as the thickness and shape, almost hemispheroidal, very slightly elongated in the longitudinal direction, of their convoluted niche. Finally, we underline the importance of the two forms from the Tithonian age, which represent the oldest cowrie taxa known today, Palaeocypraea tithonica and Bernaya gemmellaroi.

Storm deposits and trace fossils of Xinji Formation (Cambrian Series 2) in the southern margin of North China Plate

The Xinji Formation (Cambrian Series 2) in the southern margin of the North China Plate developed typical siliciclastic storm deposits and abundant trace fossils. These deposits are characterized by essential indicators, such as erosional surfaces, lag deposits, blocky beddings, hummocky cross stratifications, horizontal or wavy beddings. Storm deposits in the study area are dominated by the development of hummocky cross stratifications, which is categorized into five storm deposit types based on the arrangement of different sedimentary units in the profile. These five types of storm deposits from I to V show the transition from proximal storm deposits to distal storm deposits, the gradual weakening of storm intensity, and the associated growth of quiescent intervals. The trace fossils are mainly developed in the sandstone-mudstone interbeds between storm events and include 14 ichnospecies in 11 ichnogenera: Didymaulichnus isp., Gordia marina, Helminthopsis tenuis, Oldhamia radiata, Palaeophycus striatus, Palaeophycus tubularis, Phycodes isp., Planolites beverleyensis, Planolites montanus, Planolites punctatus, Skolithos isp., Taenidium isp., Torrowangea rosei, Treptichnus pedum. By analyzing the ichnological index (burrow size, BPBI, ichnodiversity and ichnodisparity) from different storm deposits, it can be seen that from storm deposit type I to storm deposit type V, the ichnological index shows an increasing trend. Combined with the relationship between storm deposits and trace fossils, it is inferred that differences in storm intensity result in different colonization windows, and thus variations in ichnological index of preserved trace fossils. Based on the characteristics of storm deposits and distribution of trace fossils, the preservation forms of trace fossils under storm influence are explored.

Torosites: A New Microbially Mediated Speleothem from Sistema los Toros, Nuevo Léon, Mexico

Although several kinds of speleothems are known to grow with pendant morphology (i.e., helictites, pool fingers, and stalactites), we describe here a new form found in Sistema Los Toros, Nuevo Léon, Mexico, which we propose to call torosites. A laminated, bladed, spar crust grew beneath remnants of a stromatolitic micritic crust and extended mostly downward as irregular finger-like protrusions (torosites) that are 2–3 mm wide and 2–3 cm long. Although mainly pendants, the individual torosites are quite irregular with growth sideways and even upward in places. The torosites thicken and thin, like knuckles on a finger, but maintain a relatively uniform diameter. Laminations in the bladed spar and protrusions are defined by micritic intervals with minor intermixed detrital grains (clay, quartz, and carbonate silt) and rare, ropy biofilm. Bladed-spar crystals nucleate off thicker detrital layers, but they extend through thinner lamina. The torosites lack the central canal of helictites and most stalactites. Unlike pool fingers and stalactites, torosites only grow on the end of the speleothem, not on the sides. We hypothesize that the torosites grew from dripping water at their ends. Microbial biofilm communities colonized the growth surface, probably during drier conditions, forming the micritic layers. We speculate that the microbial mat likely caused the irregular sideways growth, but we cannot identify how on these fossil forms. Torosites are unique and add to the growing list of known microbially mediated speleothems.

Flabellophyton: The Benthic Macroalgal Fossils in Marwar Supergroup, India

ABSTRACT Here we report numerous fossil forms of the Ediacaran Flabellophyton genus in the Sonia Sandstone of the Jodhpur Group, Marwar Supergroup, in India. They are assigned as Flabellophyton lantianense, Flabellophyton stupendum, and Flabellophyton typicum species and have been found to have both positive and negative reliefs on the bedding planes of medium- to fine-grained sandstone in the Sursagar region of Jodhpur district. The thallus of Flabellophyton lantianensis occurs in straight to slightly curved and slender forms, is closely packed, and may have thin filaments. The Flabellophyton stupendum is a conical or fan-shaped thallus containing thin bundled filaments and has a discoidal holdfast with a well-differentiated stipe. The Flabellophyton typicum species typically has a thallus with an intermediate conical shape, a globular holdfast with an acute stipe, and a fan-shaped form with bundles of thin filaments. These studied Flabellophyton fossil assemblages are well comparable to those found in South China and South Australia in their conical or fan-shaped morphologies and holdfast structures (mostly found in F. stupendum and F. typicum species) with fine and thin bundled filaments. In accordance with this study, these Flabellophyton fossil assemblages are probably benthic macroalgal fossils. Here, the fossil assemblages of Flabellophyton from India are described for the first time.

Chuaria and Tawuia fossils from ∼1.0 Ga rocks in North China: Implications for a polyphyletic origin of Chuaria and a potential biological link between these two widespread Proterozoic taxa

The Proterozoic witnessed the emergence and rise of early eukaryotes and Proterozoic carbonaceous compression macrofossils provide a valuable window for our understanding of this ecological expansion. Among them, the discoidal Chuaria and tomaculate Tawuia, which often co-occur in the same bedding layer, are perhaps the most common fossil forms in Proterozoic successions with extremely long temporal and broad geographical distributions. However, their phylogenetic interpretations and the relationship between them have been debated for decades, due to their simple morphologies lacking phylogenetically diagnostic features. In this study, we used an integrated application of reflected and transmitted light microscopy, scanning electron microscopy, biometric analysis, and Raman spectroscopy to characterize well-preserved carbonaceous compression macrofossils of Chuaria and Tawuia from the Tonian Liulaobei Formation in Huainan region, northern Anhui province, North China. The fossils are abundantly preserved in a ca. 1–2 cm thick homogeneous mudstone layer and can be considered to be closer to an ecological community than fossils from multiple different layers or localities. The comprehensive analysis shows that even Chuaria vesicles from the same layer may have a polyphyletic origin and three groups of Chuaria vesicles have been identified. Among them, small Chuaria vesicles with minimum diameter < 1.2 mm can be either related to the sphaeromorphic acritarch Leiosphaeridia or interpreted as multicellular aggregates. In contrast, large Chuaria vesicles with minimum diameter ≥ 1.2 mm are more comparable to the type material of Chuaria circularis from the Chuar Group and more closely related, either phylogenetically or ontogenetically, to Tawuia vesicles. This study takes a step on the path to solving the mystery of the most common and widely distributed Proterozoic macrofossil assemblage (i.e., Chuaria-Tawuia assemblage), and urges thorough and systematic evaluations to be taken on the possibility that Chuaria vesicles from the same Chuaria-Tawuia assemblages or sole Chuaria assemblages in other localities might also be polyphyletic.

Fossil endocarps of Menispermaceae from the late Paleocene of Paris Basin, France

AbstractMenispermaceae are an angiosperm family of mostly climbing plants distributed throughout tropical regions. The fruits in this family have a strong sclerified endocarp and can be used for reliable species‐level identifications, even in a fossilized form. New Paleocene‐age menispermaceous endocarps have recently been discovered in South America and Asia, while in Europe, they are mostly found in the Eocene. This paper focuses on the study of fossil endocarps belonging to Menispermaceae, found in the Petit‐Pâtis locality, which is one of the few Paleocene localities in Europe. The locality is dated to the late Paleocene (57–56 Ma) and the fossils represent flora and fauna in the Paris Basin before the onset of the Paleocene–Eocene Thermal Maximum. Lignitized fossils were photographed and their morphology was analyzed using computed tomography, scanning electron microscope, and geometric morphometric analysis. The analysis of 36 fossils belonging to Menispermaceae revealed that three genera (Stephania, Palaeosinomenium, Tinospora) were present in the late Paleocene of Paris Basin. Differences in internal morphology and a more inflated endocarp base led to a description of a new fossil species—Palaeosinomenium oisensis sp. nov. The occurrence of these genera in the Paleocene of France is consistent with the suggestion that megathermal flora was present in the Paris Basin before the Paleocene–Eocene Thermal Maximum. These three genera are currently the oldest occurrences in Europe, highlighting the connection between paleofloras of the Americas, Europe, and Asia in the Paleocene.

N-Alkane Biosignatures in a High Arctic Mars Analogue Gossan Deposit

If past life ever existed on Mars, what are the multiple ways it could have been preserved in the Martian geological record? This crucial question is becoming especially relevant the more we uncover about the planet’s ancient wet history. Different acidic and sulfur rich analog environments have been proposed that are comparable to the alteration environments of iron oxides and sulfate minerals on Mars. However, some authors have hypothesized that these past Martian environments might have been cold and semi-dry, similar to polar regions on Earth. As part of the T-MARS team, we studied reactive gossans in the Canadian High Arctic, on Axel Heiberg Island, as an analog environment to similar deposits on Mars. We hypothesized that n-alkane lipids could potentially be an important form of molecular fossils entombed in varying mineral assemblages of sulphates, iron oxides, and phyllosilicates in Arctic gossans, because of their excellent preservation potential relative to most other forms of organic molecules. To determine the preservation potential of lipids in mineralogically varying acidic sulfur rich gossan deposits, this study extracted and quantified n-alkane biomarkers from three different Arctic gossans with gas chromatography–mass spectrometry (GC-MS). Total organic carbon, pH, and mineralogy were also determined. Organic matter was found to be very low in all samples (&amp;lt;1% wt.%). N-alkane analysis also revealed preserved even-over-odd distribution patterns in short chain n-alkanes, most likely from a microbial source, along with evidence for long-chain n-alkanes with odd-over-even distribution from higher plant sources. The presence of these unique chemical biosignatures in low organic, highly acidic, and sulfur rich Mars analog gossans of varying maturity provides evidence that sulfur deposits linked to paleo hydrothermal systems on Mars can be promising targets for preserved organic biosignatures, specifically lipid n-alkanes. The significant diversity in biosignature patterns across samples of varying mineralogy, pH, and oxidation levels within each gossan suggests that n-alkane preservation varies on a small scale in these environments. These factors alone do not definitively account for the variability of n-alkane concentrations and distributions in this study, and additional investigations of these and other influencing factors are needed to determine which specific targets to choose for biosignature search on Mars in future space missions. This exploratory study provides novel insights into the lipid biosignature content in high Arctic Mars analogue gossan deposits.

Human Fossils from the First Quarter of the 21st Century

Significant discoveries have been made from the first quarter of this Century in the field of evolutionary biology to redefine the human evolution. Discoveries present the morphological variability in fossil forms and indicate the valuable role of that particular continent in tracing the human origin. This article presents a general review of the human fossils found so far of this century that force us to rethink about the current concept of human origin. Most of the fossils have been found in East Africa, South Africa, Central Africa, Russia, Israel and Indonesia. Some of these are related to Australopithecus afarensis, some to Aus. africanus while some to Neanderthal. A complete human skeleton remains has been found from Ethiopia (Middle Awash region) and named as Ardipithecus ramidus is believed to be the common ancestor of humans and chimpanzees. Naser Ramla from Israelis considered as an ancestor of Neanderthals because it used stone tool production technology to make tools. Some fossils share features of both Australopithecus and early Homo, such as Orrorin tugenesis and Homo naledi. Australopithecus deyremeda is considered as an extinct species of Australopithecine. Some of these are contemporary of modern humans, such as Homo florensis, whose complete skeleton has been found from the Flores island of Indonesia and it has also been considered as an Asian descendant of Homoerectus. Denisovans found in Russia's Denisova cave is considered as a new species, it belongs to the Lower Middle Palaeolithic period, so it is also considered to be related to Neanderthal, although its fossil remains include only digit bone, 4 tooth, parts of jaw and long bones and parietal part of the cranium.

A New Species of Sandgrouse (Aves: Pteroclidae) from the Early Pleistocene of the Crimea.

Sandgrouse (Pteroclidae, Pterocliformes) are specialized ground birds of open arid landscapes with a very poorly studied evolutionary history. In the late Pliocene-early Pleistocene, Pteroclidae are known only from few localities in Southern Europe. The article describes a relatively large fossil sandgrouse from the early Pleistocene of the Taurida cave in the Crimea. This is the first record of Pteroclidae in the ancient faunas of the Black Sea region and Eastern Europe. The unusual structure of the tibiotarsus makes it possible to describe the fossil form from Taurida Cave as a new species, Pterocles bosporanus sp. nov.

Measurements of Volatile Organic Compounds at a rural site in India: Variability and sources during the seasonal transition

Volatile Organic Compounds (VOCs) play a vital role in tropospheric ozone formation that controls the oxidative capacity of the troposphere. A total of 31 potential ozone precursor VOCs have been measured at a tropical rural site, Gadanki (13.5°N, 79.2°E) in Southern peninsular India. This study provides the primary information about different VOCs, their chemical classification and potential sources. There is a strong seasonal and diurnal variability among the VOC composition. n-Decane and n-dodecane dominate the other VOCs and contribute to a large fraction (>50 %) of the concentration of total VOCs (TVOCs) in winter and summer, monsoon is dominated by n-dodecane and post monsoon season has been dominated by ethane emissions. The source apportionment using interspecies correlation and Positive Matrix Factorisation (PMF) analysis resulted in four potential emission source factors namely biogenic, biomass burning/biofuel, fossil fuel and natural gas emissions. Winter and summer seasons have been dominated by VOCs originating from biomass burning/biofuel factors, monsoon has been dominated by biogenic emissions and post-monsoon season has been dominated by natural gas emissions. Even though it is a rural site, there are significant finger prints of anthropogenic emissions in the form of fossil fuel and natural gas most probably due to an adjacent national highway and long range transport. However, for the overall period, the VOCs emitted from biogenic and biomass burning together dominate the other two factors, indicating the expected source factor behaviour of a rural atmosphere.

A NEW SPECIES OF SANDGROUSE (AVES: PTEROCLIDAE) FROM THE EARLY PLEISTOCENE OF CRIMEA

Sandgrouse (Pteroclidae; Pterocliformes) are specialized ground birds of open arid landscapes with a very poorly studied evolutionary history. In the late Pliocene – early Pleistocene, Pteroclidae are known only from few localities in Southern Europe. The article describes a relatively large fossil sandgrouse from the early Pleistocene of the Taurida cave in the Crimea – this is the first finding of Pteroclidae in the ancient faunas of the Black Sea region and Eastern Europe. The unusual structure of the tibiotarsus makes it possible to describe the fossil form from Taurida Cave as a new species, Pterocles bosporanus sp. nov.

A contribution to the variability of Prunus spinosa L. in the vicinity of the mediaeval Castle Kolno, S-W Poland

The variability of fruit stone characteristics of medieval fossil forms and modern ones was analysed in a small Prunus spinosa (blackthorn) population in the vicinity of Castle Kolno near Stare Kolnie in Opole Province. A modern putative hybrid resulting from natural crossing with cultivated plums was discovered, corresponding to some fossil morphotypes. The analysis of the correlations of features indicated developmental relationships between them. The pattern of variability of the examined stones in the ordination space confirmed the development of the Prunus spinosa-Prunus domestica complex as an element of a dynamic syngameon. The population also showed variations in leaf morphotypes, which may be used in taxonomic analysis.

Ichnology of a Middle Devonian regression: Environment, terrestrialization and true substrate controls on trace fossils of the Hangman Sandstone Formation, SW England

The Eifelian-aged Hangman Sandstone Formation of southwest England is a unit of the ‘Old Red Sandstone’ that has traditionally been considered relatively barren of trace fossils. Following recent investigations, we here show it to contain the most diverse Middle Devonian non-marine ichnofauna known globally. The fluvial-lacustrine facies of its constituent Trentishoe Member contain representatives of 21 ichnogenera including Archaeonassa, Arenicolites, Beaconites, Bifungites, Circulichnis, Cruziana, Diplichnites,?Gluckstadella, Gordia,?Halimededes,?Lockeia, Merostomichnites, Palmichnium, Petalichnus, Planolites, Polarichnus, Rusophycus, Siskemia, Spirophyton, Steinsfjordichnus, and Taenidium, as well as several microbially induced sedimentary structures. The transitional marine-influenced facies of the underlying Hollowbrook Member are less extensively exposed but contain four additional unique ichnogenera in the form of Cochlichnus, Halopoa, Phycodes, and Teichichnus, as well as further examples of Cruziana, Planolites and Taenidium. A revised ichnological assessment of the unit reveals several notable features, including the youngest known example of the arthropod refugia trace, Polarichnus, as well as a transitional trace fossil form of Diplichnites-Beaconites, demonstrating that the latter was produced by arthropods. As the Hangman Sandstone Formation records the culmination of a marine regression, its ichnofauna can be compared with that of the conformably underlying Lynton Formation, which was deposited in a sandy marine shelf setting. The ichnological differences between these units are acute, with 88% of the Hangman Sandstone Formation trace fossils being exclusive to non-marine or transitional facies. This observation sheds light on the terrestrialization process and indicates that the segregation of marine and non-marine trace fossil communities had accelerated by the Middle Devonian. Internal variability in ichnological signatures within the Hangman Sandstone Formation is also pronounced, with greater ichnodiversity and ichnodisparity in distal fluvio-lacustrine facies than in proximal fluvial facies. By viewing the depositional environment of the unit as a regionally extensive distributive fluvial system, this variability can be partly explained by a bias arising from the distribution of true substrates (bedding planes that demonstrably preserve an ancient sediment-air interface) in the unit, with such phenomena being more readily preserved in the lower energy outer reaches of the depositional system.

Variation in the shell elements of Chrysemys picta bellii (Gray 1831)

Variation in the Shell Elements of Chrysemys picta bellii (Gray 1831) Assignment of fossil turtle shell elements to a specific taxon is often difficult because the range of variation within the population is usually not well characterized. In addition, it is sometimes not clear whether the fossil forms actually differ from their extant counterparts because often the range of shell element variation in modern species has not been determined. The emydid turtles are no exception, with confusion often arising in the identification of isolated fossil elements and sometimes intact shells representing Emys, Pseudemys, Malaclemys, and Graptemys, as well as the deirochelyids Chrysemys, Clemmys, Deirochelys, and Trachemys. In order to begin providing a database with modern counterparts of the deirochelyid turtles, I have photographed and illustrated seven extant Chrysemys picta bellii shells, six of which were collected at a single pond in Nebraska and one from Ladd Marsh in Union County, Oregon . Photographs and detailed illustrations indicate a broad range in the shapes of many characters. Side by side comparisons of some key elements show that there is significant variation in several important characters (nuchal shape/sulci, entoplastron shape/sulci, and pygal shape/sulci). I also conducted a limited morphometric analysis of several sulcus/suture distance ratios, showing substantial variation between individuals in some cases. Covariance and correlation analysis of this variation suggests that allometry is not involved in most cases. In summary, this work provides a visual and morphometric dataset for aid in identifying and assigning shell elements of fossil emydid turtles.

Lipid biomarker comparison of relict and active microbial mats from the McMurdo Ice Shelf, Antarctica

Earth’s biota leave traces in the form of molecular fossils, typically from the membrane lipids of organisms, preserved in the sedimentary rock record. However, since the environmental conditions prevailing at the time can impact the nature of those remains, it is important to understand the diagenetic processes that occur under contrasting regimes. In this study, we investigated the preservation under cold and arid climatic conditions of intact polar lipids, bacteriohopanepolyols, and quinones preserved in a ∼700-year-old relict, desiccated microbial mat. We compared these to lipid signatures in actively growing counterparts from nearby meltwater ponds of McMurdo Ice Shelf in Antarctica. Substantial differences in lipid distribution were evident between active and relict mats, suggesting that significant diagenetic degradation of lipid biomarkers occurs within a short period, thereby illuminating the selective preservation of certain polar compound classes under cold and dry conditions.

Jaw morphology and function in Drilonereis cf. filum (Oenonidae, Annelida).

Representatives of the extant family Oenonidae (Annelida, Eunicida) have a prionognath jaw apparatus, with maxillae having forceps-like elements, a number of asymmetrical dentate plates and long slender carriers, which is characteristic of some fossil forms known from the Paleozoic epoch. Therefore, data on the fine structure and functional morphology of Oenonidae jaws are helpful for the interpretation of fossil materials. The fine structure of the jaw apparatus and the ventral pharyngeal organ is studied in one species of the Oenonidae (Annelida)-Drilonereis cf. filum. The material was collected in the soft bottom of Marseille Bay (Mediterranean) and examined with the help of TEM and histological techniques. A three-dimensional (3D) reconstruction was made from a complete series of semithin sections. The entire jaw apparatus is about 500 µm in length; it includes ventral mandibles and four pairs of maxillae, connected with long paired dorsal carriers and an unpaired ventral carrier. While retracted, it reaches the VIII-XI chaetigers. The most solid part of the maxillary apparatus, that is, maxillae I and II, are 2.5-5 µm thick. The plate consists of a monolithic array of merged scleroprotein granules in which perforations, that is, spaces remaining from microvilli, are visible; the basal part of the maxillary plate is a layer of loosely arranged collagen fibers penetrated with microvilli and has no signs of sclerotization. A study of the jaws of Drilonereis cf. filum showed the presence of common jaw patterns in Eunicida order. Like the jaws of Dorvilleidae, Eunicidae, Onuphidae, and Lumbrineridae, the jaws of Drilonereis are formed at the basis of a typical annelid cuticle's transformation with epi- and basicuticular layers, and its impregnation by merging scleroprotein granules. Through the nature of sclerotization, the jaws of D. cf. filum are similar to those of Dorvilleidae, Histriobdellidae, and the juvenile jaws of Mooreonuphis stigmatis (Onuphidae). Analysis of the 3D-reconstructions of the D. cf. filum jaw apparatus shows that the MxI of this species, and probably of other Oenonidae with dorsal and ventral carriers, can make grasping motions by fixing the joint of the right and left MxI in the two-door hinge type. In general, the overall structure of the jaw apparatus of D. cf. filum and the mechanics of its work shows greater similarity with that of Dorvilleidae than with the jaw apparatus of extant Labidognatha and Simmetrognatha (Onuphidae, Eunicidae, Lumbrineridae). The need for compactization of the jaw apparatus when moving in dense sediment or in the burrows is probably one of the factors determining its structure.

New insights on the systematics of echinoids belonging to the family Spatangidae Gray, 1825 using a combined approach based on morphology, morphometry, and genetics

Spatangoids are probably the least resolved group within echinoids, with known topological incongruencies between phylogenies derived from molecular (very scarce) and morphological data. The present work, based on the analysis of 270 specimens of Spatangidae (Echinoidea, Spatangoida) trawled in the Sardinian seas (Western Mediterranean), allowed us to verify the constancy of some characters that we consider to be diagnostic at the genus level —such as the path of the subanal fasciole and the relationship between labrum and adjacent ambulacral plates —and to distinguish two distinct forms within the studied material. Based on morphological characters, morphometrics, and molecular analyses (sequencing of two mitochondrial markers: cytochrome c oxidase subunit1 (COI) and 16S), most of the individuals were classified as morphotype A and attributed to the species Spatangus purpureus, the most common spatangoid in the Mediterranean Sea, while a few corresponded to a different morphotype (B), genetically close to the species Spatangus raschi. Preliminary morphological analyses seemed to indicate that morphotype B specimens from Sardinia are slightly different from S. raschi and from Spatangus subinermis individuals, the second species of the family known to occur in the Mediterranean Sea. On the basis of morpho-structural observations and molecular analyses, comparing Mediterranean living forms with species from other areas (Central Eastern Atlantic, North Sea and neighboring basins, South African Sea, Philippines and Indonesian Archipelago, New Zealand, and Hawaiian Islands), the clear distinction of S. purpureus from several other species classified as Spatangus was confirmed. Based on the morphological and genetic differences, we propose to maintain the genus Spatangus including in it only the type species S. purpureus among the living species and to establish the new genus Propespatagus nov. gen. to include several other species previously classified as Spatangus. The clear distinction among different genera was also detected in fossil forms of Spatangus, Propespatagus nov. gen., and Sardospatangus (†) from the European Oligo-Miocene sedimentary rocks of Germany; the Miocene of Ukraine, Italy, and North Africa; the Plio-Pleistocene of Italy; and the Mio-Pliocene of Florida (USA). The new data can help in addressing taxonomic ambiguities within echinoids, as well as in improving species identification, and hence biodiversity assessments in the Mediterranean region.

A new red alga preserved with possible reproductive bodies from the 518‐million‐year‐old Qingjiang biota

AbstractMacroalgae have been a key ecological component of marine ecosystems since the Proterozoic period and are common fossil forms in Cambrian Burgess Shale‐type Lagerstätten. However, in most cases, it is difficult to place these early fossil algae into modern groups because little distinctive morphology is preserved. Here, we describe a new form of macroalgae, Qingjiangthallus cystocarpium gen. &amp; sp. nov., from the Qingjiang biota of South China. The new taxon is represented by 546 specimens remarkably preserved with characteristics that allow a phylogenetic placement into crown groups of red algae. Centimeter‐sized thalli resemble members of the extant Rhodymeniophycidae (a subclass of the class Florideophyceae), and hence suggest a florideophycean affinity, which indicates that ahnfeltiophycidaen and rhodymeniophycidaen algae may have diverged at least 518 Ma, accordant with estimations of molecular studies. The presence of possible cystocarps on Qingjiangthallus thalli suggests that evolutionary innovation of a triphasic life cycle in red algae may have occurred no later than the Early Cambrian. The branching patterns and branch width of Qingjiangthallus are consistent with the coarsely dichotomously branched morphogroup, which was previously present in the Ediacaran, Ordovician, and afterward, but absent in the Cambrian.

Climate change vs energy security? The conditional support for energy sources among Western Europeans

The decarbonisation of Western societies requires a fundamental reorganisation of energy supply and fierce debates around the future energy mix have begun in many countries. However, we still know little about how concerns about energy security affect the public's energy preferences in view of the critique that renewable energies might compromise energy security. This paper argues that there is a perceived trade-off between energy security and climate protection that affects energy supply preferences in Western Europe. Using the European Social Survey's ‘Public Attitudes to Climate Change’ module, the findings from multilevel regressions demonstrate that there is indeed a perceived trade-off in energy preferences among Western Europeans. People concerned about energy security prefer coal, gas, and nuclear power over renewable energies. People worried about climate change prefer solar and wind energy over nuclear and fossil forms of energy. The analysis further identifies four different groups representing the trade-off between energy security and climate protection among Western Europeans. The paper thus identifies why energy preferences might collide and why some countries observe a polarisation of views around energy supply that policymakers need to address to realise a successful and publicly acceptable transformation of energy supply.