An Integrated Study on Late Cisuralian (Early Permian) Palaeoenvironments and Palaeoclimate of Southern Alps

The transition from ice-house to green-house conditions that characterized the Permian (289–252 million years ago) climate passed through several glacial and interglacial phases and an increase of aridity, which affected the palaeoequatorial regions. The causes behind this increase, which led to several important changes within the terrestrial ecosystems, are still poorly understood. During the Permian, extrabasinal floras, mainly composed of drought-tolerant plants such as conifers and other gymnosperms, started to spread and move into the lowlands, progressively replacing the hygrophytic lowland floras that characterized the Carboniferous peat-forming forests. These climate changes and terrestrial biotic turnover left an important imprint in the carbon stable isotopic composition of the atmospheric CO2, and consequently, of the terrestrial organic matter. However, the step-wise nature of the Permian palaeofloristic transition and the low-resolution of δ13C data on the terrestrial organic matter make it difficult to clearly reconstruct what happened to the Permian palaeoequatorial ecosystems. A palaeoenvironmental and palaeoclimate reconstruction of the Kungurian (Cisuralian, early Permian) Tregiovo Basin (NE-Italy) is here provided. A multidisciplinary study has been carried out, through which two sections of the Tregiovo Formation, respectively “Le Fraine” and Tregiovo village sections, have been investigated for sedimentology, geochemistry, palaeobotany and palynology. The taxonomical study on the two rich palaeobotanical assemblages of the “Le Fraine” section revealed a very diverse and abundant flora, composed of sphenophytes (Annularia), ginkgophytes (?Sphenobaiera), pteridosperms (Peltaspermum), conifers (e.g., Hermitia, Feysia, Quadrocladus, Dolomitia) and taxa with uncertain botanical affinity like taeniopterids (Taeniopteris), sphenopterids (Sphenopteris) and two incertae sedis “morphotypes”. The palaeobotanical and palynological study indicates a xerophytic character for the Tregiovo flora, mainly dominated by conifers and sphenopterids. A thorough taxonomical study on these two plant groups showed a remarkable diversity, which allowed to pre-date the first appearance of genus Dolomitia to be moved back to the Kungurian, and to identify a new sphenopterid species, Sphenopteris valentinii. Sedimentological studies from the two sections indicate a playa-lake environment alternating with stable lacustrine conditions. Lake phases are indicated by common microbial carbonates, whereas playa-lake phases are indicated by the occurrence of mud-cracks and tetrapod footprints. Stable isotopic analyses on bulk organic carbon and conifer coalified tissues from the two Tregiovo sections highlighted a distinct negative shift of the δ13C curve on the terrestrial organic carbon within the Tregiovo Formation, well-constrained to the middle Kungurian by radiometric data, that correlates very well with the negative shift recorded by other authors for the Kungurian. This work represents a contribution to the comprehension of the complex picture of Permian palaeoenvironments and palaeoclimate, filling a gap on the knowledge about the early Permian eastern palaeoequatorial ecosystems

AMBER DROPLETS IN THE SOUTHERN ALPS (NE ITALY): A LINK BETWEEN THEIR OCCURRENCES AND MAIN HUMID EPISODES IN THE TRIASSIC

The Anisian amber from the “Voltzia beds” of the Recoaro area, produced by Voltzia recubariensis, represents the most ancient Triassic amber known so far. The discovery of amber in the Anisian localities of Kühwiesenkopf/Monte Prà della Vacca and Piz da Peres, in the Dolomites area, fills a gap in the amber fossil record and gives an important contribution to the knowledge of Triassic amber. The finding of amber droplets, both dispersed in the sediment and anatomically connected to shoot fragments of V. recubariensis, demonstrates that during the Anisian this species was a major resin-producer and that the favorable conditions for the preservation of resin and plant remains were present at regional scale. The contribution of Voltziales to Middle Triassic resin production in Northern Italy is also testified by the Ladinian amber from the “Wengener Schichten” of Wengen/La Valle, produced by Voltzia ladinica, whereas the Late Triassic amber was mainly produced by cheirolepidiaceous conifers. The finding of organic body trapped in the amber of Kühwiesenkopf/Monte Prà dalla Vacca is noteworthy, although difficult to interpret, and shows once again its capability to entrap and preserve witnesses of past life. Moreover, the correspondence between the Triassic amber occurrences and regional/global scale humid shifts, suggests a cause-and-effect relationship, in which the rise of amber production/preservation potential is related to climate/environmental changes, particularly in marginal marine/costal environments

The effects of the exposure to neurotoxic elements on Italian schoolchildren behavior

Neurodevelopmental disorders are constantly increasing on a global scale. Some elements like heavy metals are known to be neurotoxic. In this cross-sectional study we assessed the neurobehavioral effect of the exposure to trace elements including lead, mercury, cadmium, manganese, arsenic and selenium and their interactions among 299 schoolchildren residing in the heavily polluted Taranto area in Italy. Whole blood, urine and hair were collected for metal analyses, while the Child Behavior Checklist and the Social Responsiveness Scale, administered to the main teacher and the mothers were considered to identify behavioral problems in children. Blood lead mainly influenced social problems, aggressive behavior, externalizing and total problems. Urinary arsenic showed an impact on anxiety and depression, somatic problems, attention problems and rule breaking behavior. A significant interaction between lead and arsenic was observed, with a synergistic effect of the two metals increasing the risk of attention problems, aggressive behavior, externalizing problems and total problems. Overall, we were able to test that higher blood lead, urinary arsenic concentrations and their interaction increase the risk of neurobehavioral problems. This is in line with the U.S. Environmental Protection Agency’s priority list of hazardous substances where arsenic and lead are ranked as first and second respectively

The Permian (Kungurian, Cisuralian) palaeoenvironment and palaeoclimate of the Tregiovo Basin, Italy: Palaeobotanical, palynological and geochemical investigations

A transition from widespread humid to more drought tolerant floras characterized tropical terrestrial ecosystems during the Permian (Cisuralian). Tregiovo (Southern Alps, N-Italy) is one of the very few well dated Kungurian (late Cisuralian) plant localities in Euramerica. It was located in eastern palaeoequatorial Pangea. Two units bearing fossil plant assemblages occur in finely laminated sediments deposited in a playa-lake environment. In this paper, the sedimentology of the Tregiovo Basin is reviewed, and new palaeobotanical, palynological and stable isotopic data are presented, in order to reconstruct the palaeoclimatic and palaeoenvironmental conditions of the Kungurian in the Southern Alps. Both fossil plant assemblages are dominated by conifers (Hermitia, Feysia, Quadrocladus, Dolomitia), together with sphenophytes (Annularia), ginkgophytes (Sphenobaiera), pteridosperms (Peltaspermum), taeniopterids and sphenopterids. These taxa, which occur with different abundances in the two plant assemblages, both indicate semi-arid conditions. Associated palynoflora, dominated by bisaccate pollen, and extremely rare spore occurrences, is consistent with the xerophytic character of the macroflora, and suggests that the fossil plant record was not affected by collection or preservation bias. Stable isotopic analyses of two stratigraphic sections reveal an upward trend of increasingly negative \u3b413Corg (VPDB), which may correlate with roughly coeval records from marine and continental successions such as in North China and South Africa. This isotopic shift may be attributed to a global perturbation of atmospheric \u3b413C, although the influence of local environmental factors cannot be excluded

Kungurian (Cisuralian) conifers and environmental changes: a negative δ13C shift in the flora of Tregiovo (Northern Italy)

The Le Fraine fossil locality, near the Tregiovo village (Trento Province, northern Italy) yields two of the best documented Kungurian (early Permian) plant fossil assemblages of eastern palaeoequatorial Pangea. Both plant assemblages (Tregiovo A and B) are dominated by walchian and voltzian conifers but differ in the relative abundance of the major plant groups. Analyses of the δ13C of the bulk organic carbon throughout the entire stratigraphic succession of Tregiovo show a negative trend towards the upper part of the succession. Several conifer taxa are recognized and taxon-specific δ13C analyses of the conifer remains in both plant fossil assemblages shows the same trend in all taxa. This correlation between the negative shift of the bulk organic carbon and the taxon-specific δ13C analysis shows that the negative δ13C shift recorded along the stratigraphic section is not the result of change in relative abundance within the plant assemblages but instead has an external cause, likely the δ13C values of atmospheric CO2. These results agree well with a negative shift observed in other Kungurian continental successions (e.g., China, South Africa, Australia), supporting a global perturbation in the carbon cycle. The negative shift in δ13C could very well record the last deglaciation phases of the Late Paleozoic Ice Age and the rise of the atmospheric pCO2

Conifer Cone and Dwarf Shoot Diversity in the Anisian (Middle Triassic) of Kühwiesenkopf/Monte Prà della Vacca (Dolomites, Northeastern Italy)

Premise of research. The diversity of conifers from Kühwiesenkopf/Monte Prà della Vacca has been inferred previously on the basis of foliate branches/shoots and epidermal morphology. In this article we provide the description of the reproductive organs, which reveal a variety of forms, new morphologies and new taxa, and a comparison with other Permian–Triassic taxa, improving the knowledge of Triassic conifers. Methodology. The macromorphology, cuticles, and in situ pollen of the reproductive organs are described, and the macromorphological features are compared with those of other Permian–Triassic taxa. Pivotal results. The macro- and micromorphological analyses of the conifer reproductive organs of Kühwiesenkopf/Monte Prà della Vacca allow us to emend previously known taxa (i.e., Voltzia heterophylla, V. walchiaeformis, V. recubariensis, Pseudovoltzia edithae) and to describe new ones (i.e., cf. Voltzia sp. 1, Sidashia tridentata), providing in some cases almost complete whole-plant reconstructions. The macromorphological comparison of the Kühwiesenkopf/Monte Prà della Vacca taxa with other Permian–Triassic ones highlights the transitional character of some of them, especially P. edithae. The finding of amber anatomically connected to a V. walchiaeformis seed cone evidences the diversity of the botanical origins of the Anisian amber. Conclusions. The reproductive organs of the conifers of Kühwiesenkopf/Monte Prà della Vacca show in their morphology a mixture of characters typical of the early Permian to the Late Triassic Voltziales. Their study improves our knowledge of the reproductive biology of Anisian conifers and confirms the pivotal role of the “transitional” Triassic Voltziales that gave rise to modern groups of conifers

Sphenopterid diversity in the Kungurian of Tregiovo (Trento, NE-Italy)

The lower Permian fossiliferous deposit of Tregiovo, in the upper Val di Non (Trento Province, N-Italy), is known from the beginning of last century, since it has yielded invertebrate and vertebrate footprints, palynomorphs, conchostracans, and especially plant remains. In recent years, a new section in the Tregiovo Formation, called “Le Fraine”, located along the Lauregno provincial road, has been discovered. Two fossiliferous layers in this new section, one in the lower and one in the upper part of the section, yielded different plant assemblages. The radiometric dating of the volcanic formations under- and overlying the Tregiovo Formation, indicates a middle Kungurian age for the fossil-bearing sequence. More than 1000 specimens, impressions and compressions but without cuticles, have been found. The two plant assemblages are rich and diverse, and both are dominated by conifers (e.g., Feysia, Hermitia, Dolomitia) that range from 60 to 80% of the total assemblage, but also sphenophytes (Annularia), taeniopterids (Taeniopteris) and ginkgophytes (Sphenobaiera) occur. Most remarkable of these two assemblages is the high diversity of sphenopterids that are sometimes preserved as complete fronds. At least five different species can be attributed to the genus Sphenopteris, i.e. Sphenopteris kukukiana, Sphenopteris suessii, Sphenopteris. sp. cf. S. geinitzii, Sphenopteris sp. and a morphotype that represents a new species, Sphenopteris valentinii. The leaves of most Sphenopteris species look pretty stiff and have strongly dissected pinnules with very narrow, linear rigid segments, apparently being an adaptation to arid conditions. The Tregiovo flora is of great importance, not only because of its richness and diversity, especially with regard to sphenopterids, but also because it is one of the very few well-dated Kungurian floras from Euramerica

Sphenopterid diversity in the Kungurian of Tregiovo (Trento, NE-Italy)

The lower Permian fossiliferous deposit of Tregiovo, in the upper Val di Non (Trento Province, N-Italy), is known from the beginning of last century, since it has yielded invertebrate and vertebrate footprints, palynomorphs, conchostracans, and especially plant remains. In recent years, a new section in the Tregiovo Formation, called “Le Fraine”, located along the Lauregno provincial road, has been discovered. Two fossiliferous layers in this new section, one in the lower and one in the upper part of the section, yielded different plant assemblages. The radiometric dating of the volcanic formations under- and overlying the Tregiovo Formation, indicates a middle Kungurian age for the fossil-bearing sequence. More than 1000 specimens, impressions and compressions but without cuticles, have been found. The two plant assemblages are rich and diverse, and both are dominated by conifers (e.g., Feysia, Hermitia, Dolomitia) that range from 60 to 80% of the total assemblage, but also sphenophytes (Annularia), taeniopterids (Taeniopteris) and ginkgophytes (Sphenobaiera) occur. Most remarkable of these two assemblages is the high diversity of sphenopterids that are sometimes preserved as complete fronds. At least five different species can be attributed to the genus Sphenopteris, i.e. Sphenopteris kukukiana, Sphenopteris suessii, Sphenopteris. sp. cf. S. geinitzii, Sphenopteris sp. and a morphotype that represents a new species, Sphenopteris valentinii. The leaves of most Sphenopteris species look pretty stiff and have strongly dissected pinnules with very narrow, linear rigid segments, apparently being an adaptation to arid conditions. The Tregiovo flora is of great importance, not only because of its richness and diversity, especially with regard to sphenopterids, but also because it is one of the very few well-dated Kungurian floras from Euramerica