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1.
Proc Natl Acad Sci U S A ; 116(9): 3431-3436, 2019 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-30808737

RESUMO

Evidence for macroscopic life in the Paleoproterozoic Era comes from 1.8 billion-year-old (Ga) compression fossils [Han TM, Runnegar B (1992) Science 257:232-235; Knoll et al. (2006) Philos Trans R Soc Lond B 361:1023-1038], Stirling biota [Bengtson S et al. (2007) Paleobiology 33:351-381], and large colonial organisms exhibiting signs of coordinated growth from the 2.1-Ga Francevillian series, Gabon. Here we report on pyritized string-shaped structures from the Francevillian Basin. Combined microscopic, microtomographic, geochemical, and sedimentologic analyses provide evidence for biogenicity, and syngenicity and suggest that the structures underwent fossilization during early diagenesis close to the sediment-water interface. The string-shaped structures are up to 6 mm across and extend up to 170 mm through the strata. Morphological and 3D tomographic reconstructions suggest that the producer may have been a multicellular or syncytial organism able to migrate laterally and vertically to reach food resources. A possible modern analog is the aggregation of amoeboid cells into a migratory slug phase in cellular slime molds at times of starvation. This unique ecologic window established in an oxygenated, shallow-marine environment represents an exceptional record of the biosphere following the crucial changes that occurred in the atmosphere and ocean in the aftermath of the great oxidation event (GOE).


Assuntos
Evolução Biológica , Fósseis , Sedimentos Geológicos/química , Oxigênio/química , Atmosfera , Biota/fisiologia , Gabão , Oxirredução
2.
Aquaculture ; 553: 738127, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36267956

RESUMO

From the beginning of March 2020 and for the following two and half months, many European countries comprising Italy have been forced into an unprecedented lockdown, allowing only the opening of essential economic activities needed to address the problems created by the pandemic (e.g. sanitary, food provision). Like many sectors of the Italian economy, aquaculture has also slowed down due to the ongoing emergency and the consequent closure of business. In our study we provided a 'snapshot' of the socio-economic effects of the lockdown on the aquaculture sector in Italy, immediately following the adoption of the COVID-19 restrictions as they were perceived by the workers. Although it was surveyed for a short-time period, differences in perception have been detected both in relation to the type of aquaculture as well as to the geographic locations where farms were placed, partially reflecting the economic gaps already existing within the northern and the southern part of the country before the lockdown.

3.
Environ Sci Policy ; 127: 98-110, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34720746

RESUMO

The COVID-19 global pandemic has had severe, unpredictable and synchronous impacts on all levels of perishable food supply chains (PFSC), across multiple sectors and spatial scales. Aquaculture plays a vital and rapidly expanding role in food security, in some cases overtaking wild caught fisheries in the production of high-quality animal protein in this PFSC. We performed a rapid global assessment to evaluate the effects of the COVID-19 pandemic and related emerging control measures on the aquaculture supply chain. Socio-economic effects of the pandemic were analysed by surveying the perceptions of stakeholders, who were asked to describe potential supply-side disruption, vulnerabilities and resilience patterns along the production pipeline with four main supply chain components: a) hatchery, b) production/processing, c) distribution/logistics and d) market. We also assessed different farming strategies, comparing land- vs. sea-based systems; extensive vs. intensive methods; and with and without integrated multi-trophic aquaculture, IMTA. In addition to evaluating levels and sources of economic distress, interviewees were asked to identify mitigation solutions adopted at local / internal (i.e., farm-site) scales, and to express their preference on national / external scale mitigation measures among a set of a priori options. Survey responses identified the potential causes of disruption, ripple effects, sources of food insecurity, and socio-economic conflicts. They also pointed to various levels of mitigation strategies. The collated evidence represents a first baseline useful to address future disaster-driven responses, to reinforce the resilience of the sector and to facilitate the design reconstruction plans and mitigation measures, such as financial aid strategies.

4.
Proc Biol Sci ; 288(1944): 20202263, 2021 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-33529560

RESUMO

Trilobites, key components of early Palaeozoic communities, are considered to have been invariably fully marine. Through the integration of ichnological, palaeobiological, and sedimentological datasets within a sequence-stratigraphical framework, we challenge this assumption. Here, we report uncontroversial trace and body fossil evidence of their presence in brackish-water settings. Our approach allows tracking of some trilobite groups foraying into tide-dominated estuaries. These trilobites were tolerant to salinity stress and able to make use of the ecological advantages offered by marginal-marine environments migrating up-estuary, following salt wedges either reflecting amphidromy or as euryhaline marine wanderers. Our data indicate two attempts of landward exploration via brackish water: phase 1 in which the outer portion of estuaries were colonized by olenids (Furongian-early late Tremadocian) and phase 2 involving exploration of the inner to middle estuarine zones by asaphids (Dapingian-Darriwilian). This study indicates that tolerance to salinity stress arose independently among different trilobite groups.


Assuntos
Artrópodes , Animais , Estuários , Fósseis , Águas Salinas
5.
Glob Chang Biol ; 27(12): 2645-2655, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33638211

RESUMO

Over the years, concern about the effects of microplastics has grown. Here, we answered the main question "What are the impacts of microplastics on the functional traits of fish species?" through a meta-analysis. The general impact of microplastic exposure on the functional traits of fishes and specifically on eight variables, namely, behaviour, development, fecundity, feeding, growth, health, hatching and survival was explored. Subgroup analyses were performed to detect correlations between the impact of microplastics and the following factors: species, life stage, habitat, water column habitat, day of exposure to microplastics and microplastic size, type and shape. A meta-regression analysis allowed understanding the correlation between the impact of microplastics and the size of organisms. Generally, microplastics have a negative effect on the functional traits of fishes. Feeding and behaviour, followed by growth showed the greatest impact. Among the subgroup analysis, four of the eight variables considered showed a significant difference between groups: species, life stage, microplastic shape and days of exposure to microplastics. Depending on their life stage, organisms may be more sensitive to microplastic pollution. Changes in growth rates, development of early life stage and behavioural patterns in fishes may have a negative effect on the structure and functions of aquatic ecosystem in the long term and consequently affect the ability of aquatic ecosystems to provide ecosystem services and sustain human communities.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Ecossistema , Monitoramento Ambiental , Peixes , Humanos , Plásticos , Poluentes Químicos da Água/análise
7.
J Environ Manage ; 223: 749-757, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29986322

RESUMO

Many recent studies have focused their attention on the physiological stress experienced by marine organisms in measuring ecotoxicological responses. Here we suggest a new approach for investigating the effects of an anthropogenic pollutant on Life-History (LH) traits of marine organisms, to provide stakeholders and policy makers an effective tool to evaluate the best environmental recovery strategies and plans. A Dynamic Energy Budget (DEB), coupled with a biophysical model was used to predict the effects of a six-month oil spill on Mytilus galloprovincialis' LH traits and to test two potential recovery strategies in the central Mediterranean Sea. Oxygen consumption rates were used to check for increasing energetic maintenance costs [pM] respectively in oil-polluted system treatments (∼76.2%) and polluted systems with physical (nano-bubbles ∼32.6%) or chemical treatment (dispersant ∼18.4%). Our model outputs highlighted a higher growth reduction of intertidal compared to subtidal populations and contextually an effect on the reproductive output and on the maturation time of this latter. The models also enabled an estimation of the timing of the disturbance affecting both the intertidal and subtidal populations' growth and reproduction. Interestingly, results led to the identification of the chemical dispersant as being the best remediation technique in contexts of oil spill contamination.


Assuntos
Mytilus , Poluição por Petróleo , Poluentes Químicos da Água , Animais , Organismos Aquáticos , Monitoramento Ambiental , Mar Mediterrâneo , Reprodução
8.
J Viral Hepat ; 24(10): 858-864, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28370880

RESUMO

Long-term functional outcomes of sofosbuvir-based antiviral treatment were evaluated in a cohort study involving 16 Italian centres within the international compassionate use programme for post-transplant hepatitis C virus (HCV) recurrence. Seventy-three patients with cirrhosis (n=52) or fibrosing cholestatic hepatitis (FCH, n=21) received 24-week sofosbuvir with ribavirin±pegylated interferon or interferon-free sofosbuvir-based regimen with daclatasvir/simeprevir+ribavirin. The patients were observed for a median time of 103 (82-112) weeks. Twelve of 73 (16.4%) died (10 non-FCH, 2 FCH) and two underwent re-LT. Sustained virological response was achieved in 46 of 66 (69.7%): 31 of 47 (66%) non-FCH and 15 of 19 (79%) FCH patients. All relapsers were successfully retreated. Comparing the data of baseline with last follow-up, MELD and Child-Turcotte-Pugh scores improved both in non-FCH (15.3±6.5 vs 10.5±3.8, P<.0001 and 8.4±2.1 vs 5.7±1.3, P<.0001, respectively) and FCH (17.3±5.9 vs 10.1±2.8, P=.001 and 8.2±1.6 vs 5.5±1, P=.001, respectively). Short-treatment mortality was higher in patients with baseline MELD≥25 than in those with MELD<25 (42.9% vs 4.8%, P=.011). Long-term mortality was 53.3% among patients with baseline MELD≥20 and 7.5% among those with MELD<20 (P<.0001). Among deceased patients 75% were Child-Turcotte-Pugh class C at baseline, while among survivors 83.9% were class A or B (P<.0001). Direct acting antivirals-based treatments for severe post-transplant hepatitis C recurrence, comprising fibrosing cholestatic hepatitis, significantly improve liver function, even without viral clearance and permit an excellent long-term survival. The setting of severe HCV recurrence may require the identification of "too-sick-to-treat patients" to avoid futile treatments.


Assuntos
Antivirais/uso terapêutico , Hepatite C/tratamento farmacológico , Hepatite C/etiologia , Hepatite/etiologia , Cirrose Hepática/etiologia , Transplante de Fígado/efeitos adversos , Idoso , Quimioterapia Combinada , Feminino , Genótipo , Hepacivirus/genética , Hepatite/diagnóstico , Hepatite C/diagnóstico , Hepatite C/virologia , Humanos , Estimativa de Kaplan-Meier , Cirrose Hepática/diagnóstico , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , RNA Viral , Recidiva , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Carga Viral
9.
J Environ Manage ; 197: 114-116, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28342997

RESUMO

In this reply we respond to the commentary of Dr. Haddaway addressed in searching for pitfalls in our systematic mapping exercise "Collating science-based evidence to inform public opinion on the environmental effects of marine drilling platforms in the Mediterranean Sea" recently published in Journal of Environmental Management (Mangano, M.C. and Sarà, G. 2017. Journal of Environmental Management 188: 195-202). We discussed each so called "pitfalls" and, in our opinion, the main cornerstones of systematic map - SM (repeatability, comprehensiveness, transparency, traceability, quality, generalizability) are safe guaranteeing the "gold standard" required by this technique. Where needed we explain our position in doing a "tailoring" of some steps, and we stressed the differences among our approach and a SM protocol. We also stressed the importance of our main message, to select the most rigorous approach (evidence-based), to create a credible, salient and effective knowledge baseline to inform end users and guarantee the creation of a solid science-policy nexus (here specifically we provided a final review product, an easy to follow up graphical evidence).


Assuntos
Opinião Pública , Mar Mediterrâneo
10.
J Environ Manage ; 188: 195-202, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-27984792

RESUMO

The use of rigorous methodologies to assess environmental, social and health impacts of specific interventions is crucial to disentangle the various components of environmental questions and to inform public opinion. The power of systematic maps relies on the capacity to summarise and organise the areas or relationships most studied, and to highlight key gaps in the evidence base. The recent Italian technical referendum (2016) - a public consultation inviting people to express their opinion by voting to change the rules on the length of licence duration and the decommissioning of offshore oil and gas platform drilling licences - inspired the creation of a systematic map of evidence to scope and quantify the effects of off-shore extraction platforms on Mediterranean marine ecosystems. The map was aimed as a useful model to standardise a "minimal informational threshold", which can inform public opinion at the beginning of any public consultation. Produced by synthesising scientific information, the map represents a reliable layer for any future sustainable strategy in the Mediterranean basin by: (i) providing a summary of the effects of marine gas and oil platforms on the Mediterranean marine ecosystem, (ii) describing the best known affected components on which the biggest monitoring efforts have been focused, and (iii) strengthening the science-policy nexus by offering a credible, salient and legitimate knowledge baseline to both public opinion and decision-makers. The map exercise highlights the knowledge gaps that need filling and taking into due consideration before future transnational and cross-border monitoring and management plans and activities can be addressed.


Assuntos
Meio Ambiente , Campos de Petróleo e Gás , Humanos , Mar Mediterrâneo , Indústria de Petróleo e Gás , Opinião Pública
11.
Ann Surg Oncol ; 22(3): 972-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25190123

RESUMO

BACKGROUND: Sarcopenia or loss of skeletal muscle mass is an objective measure of frailty associated with functional impairment and disability. This study aimed to examine the impact of sarcopenia on surgical complications and survival outcomes in patients with endometrial cancer. METHODS: A retrospective review of endometrial cancer patients who underwent surgery between 2005 and 2009 was performed. Sarcopenia was assessed on preoperative computed tomography (CT) scan by measurement of the lumbar psoas muscle cross-sectional area and defined as any value below the median (<4.33 cm(2)). Sarcopenic obesity was defined as sarcopenia plus a body mass index (BMI) of 30 kg/m(2) or higher. Microsatellite instability (MSI) was analyzed using the National Cancer Institute (NCI) consensus markers and tumor from hysterectomy specimens. RESULTS: Of 122 patients, 27 (22%) met the criteria for sarcopenic obesity. Sarcopenic patients were older than patients with normal muscle mass (mean age, 69.7 vs. 62.1 years; p < 0.001), had a lower BMI (31.1 vs. 39.4 kg/m(2); p < 0.001), and had more comorbidities (p = 0.048). Sarcopenia was not associated with tumor MSI, hospital stay, 90-day readmission rate, or early/late complications. Patients with sarcopenia had a shorter recurrence-free survival than nonsarcopenic patients (median 23.5 vs. 32.1 months; log-rank p = 0.02), but did not differ in terms of overall survival (log-rank p = 0.25). After adjustment for race, BMI, lymphocyte count, and tumor histology, sarcopenia was associated with a fourfold shorter recurrence-free survival (adjusted hazard ratio [HRadj], 3.99; 95% confidence interval [CI], 1.42-11.3). CONCLUSIONS: Sarcopenia has an impact on recurrence-free survival, but does not appear to have a negative impact on surgical outcomes or overall survival among endometrial cancer patients who undergo preoperative CT scan.


Assuntos
Adenocarcinoma de Células Claras/cirurgia , Carcinoma Papilar/cirurgia , Cistadenocarcinoma Seroso/cirurgia , Neoplasias do Endométrio/cirurgia , Músculo Esquelético/patologia , Recidiva Local de Neoplasia/diagnóstico , Complicações Pós-Operatórias , Sarcopenia/complicações , Adenocarcinoma de Células Claras/mortalidade , Adenocarcinoma de Células Claras/patologia , Adulto , Idoso , Índice de Massa Corporal , Carcinoma Papilar/mortalidade , Carcinoma Papilar/patologia , Comorbidade , Cistadenocarcinoma Seroso/mortalidade , Cistadenocarcinoma Seroso/patologia , Neoplasias do Endométrio/mortalidade , Neoplasias do Endométrio/patologia , Feminino , Seguimentos , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Força Muscular/fisiologia , Gradação de Tumores , Recidiva Local de Neoplasia/etiologia , Recidiva Local de Neoplasia/mortalidade , Estadiamento de Neoplasias , Obesidade/complicações , Obesidade/patologia , Cuidados Pré-Operatórios , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Sarcopenia/patologia , Taxa de Sobrevida
12.
Proc Biol Sci ; 281(1780): 20140038, 2014 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-24523279

RESUMO

The rapid appearance of bilaterian clades at the beginning of the Phanerozoic is one of the most intriguing topics in macroevolution. However, the complex feedbacks between diversification and ecological interactions are still poorly understood. Here, we show that a systematic and comprehensive analysis of the trace-fossil record of the Ediacaran-Cambrian transition indicates that body-plan diversification and ecological structuring were decoupled. The appearance of a wide repertoire of behavioural strategies and body plans occurred by the Fortunian. However, a major shift in benthic ecological structure, recording the establishment of a suspension-feeder infauna, increased complexity of the trophic web, and coupling of benthos and plankton took place during Cambrian Stage 2. Both phases were accompanied by different styles of ecosystem engineering, but only the second one resulted in the establishment of the Phanerozoic-style ecology. In turn, the suspension-feeding infauna may have been the ecological drivers of a further diversification of deposit-feeding strategies by Cambrian Stage 3, favouring an ecological spillover scenario. Trace-fossil information strongly supports the Cambrian explosion, but allows for a short time of phylogenetic fuse during the terminal Ediacaran-Fortunian.


Assuntos
Biodiversidade , Evolução Biológica , Cadeia Alimentar , Fósseis , Animais , Meio Ambiente , Densidade Demográfica , Dinâmica Populacional
13.
Mar Pollut Bull ; 201: 116167, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38394793

RESUMO

Aquaculture industry represents a continuously growing sector playing a fundamental role in pursuing United Nation's goals. Increasing sea-surface temperatures, the growth of encrusting species and current cage cleaning practices proved to affect the productivity of commercial species. Here, through a Dynamic Energy Budget application under two different IPCC scenarios, we investigate the long-term effects of Pennaria disticha fragments' on Mytilus galloprovincialis' functional traits as a result of cage cleaning practices. While Climate-Change did not exert a marked effect on mussels' Life-History traits, the simulated effect of cage cleanings highlighted a positive effect on total weight, fecundity and time to commercial size. West-Mediterranean emerged as the most affected sector, with Malta, Montenegro, Morocco, Syria, Tunisia and Turkey between the top-affected countries. These outcomes confirm the reliability of a DEB-approach in projecting at different spatial and temporal scale eco-physiological results, avoiding the limitation of short-term studies and the difficulties of long-term ones.


Assuntos
Mudança Climática , Mytilus , Animais , Reprodutibilidade dos Testes , Frutos do Mar/análise , Aquicultura
14.
Sci Rep ; 14(1): 709, 2024 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-38184722

RESUMO

Exceptional paleosurfaces preserving fecal casting mounds occur in the Upper Jurassic Lastres Formation of Spain. As in modern shorelines, these biogenic structures are associated with straight to sinuous-crested ripples showing the interplay of biological and physical processes in a low-energy marine environment. These trace fossils display characteristics, distribution, and densities like those of modern arenicolid populations (approximately 35 specimens per m2). Under close examination, these fecal casting mounds are morphologically undistinguishable from those produced by recent arenicolids (e.g. Arenicola marina, Abarenicola pacifica), providing evidence of the presence of these polychaetes in the Late Jurassic. As their modern counterparts, fossil arenicolids very likely modified their environment generating a seabed topography and impacting ancient benthic communities, sediment characteristics, and sediment biogeochemistry. Although the presence of oxic microhabitats and biogeochemical processes cannot be accurately measured in the fossil record, comparison with the work of modern populations allows to make inferences on sediment reworking and bioirrigation potential. In addition, association with grazing trails supports the idea of fertilization and modulation of food resources to other species. These paleosurfaces underscore the significance of high-fidelity snapshots in the fossil record (true substrates) to reconstruct past ecologies and sediment biogeochemistry. A new ichnotaxon, Cumulusichnus asturiensis n. igen. and n. isp., is defined.


Assuntos
Ecologia , Poliquetos , Animais , Fezes , Fósseis , Refeições
15.
Mar Environ Res ; 198: 106520, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38685145

RESUMO

Altered ocean chemistry caused by ocean acidification (OA) is expected to have negative repercussions at different levels of the ecological hierarchy, starting from the individual and scaling up to the community and ultimately to the ecosystem level. Understanding the effects of OA on benthic organisms is of primary importance given their relevant ecological role in maintaining marine ecosystem functioning. The use of functional traits represents an effective technique to investigate how species adapt to altered environmental conditions and can be used to predict changes in the resilience of communities faced with stresses associated with climate change. Artificial supports were deployed for 1-y along a natural pH gradient in the shallow hydrothermal systems of the Bottaro crater near Panarea (Aeolian Archipelago, southern Tyrrhenian Sea), to explore changes in functional traits and metabolic rates of benthic communities and the repercussions in terms of functional diversity. Changes in community composition due to OA were accompanied by modifications in functional diversity. Altered conditions led to higher oxygen consumption in the acidified site and the selection of species with the functional traits needed to withstand OA. Calcification rate and reproduction were found to be the traits most affected by pH variations. A reduction in a community's functional evenness could potentially reduce its resilience to further environmental or anthropogenic stressors. These findings highlight the ability of the ecosystem to respond to climate change and provide insights into the modifications that can be expected given the predicted future pCO2 scenarios. Understanding the impact of climate change on functional diversity and thus on community functioning and stability is crucial if we are to predict changes in ecosystem vulnerability, especially in a context where OA occurs in combination with other environmental changes and anthropogenic stressors.


Assuntos
Biodiversidade , Mudança Climática , Ecossistema , Oceanos e Mares , Água do Mar , Concentração de Íons de Hidrogênio , Água do Mar/química , Animais , Organismos Aquáticos/efeitos dos fármacos , Organismos Aquáticos/fisiologia , Dióxido de Carbono , Monitoramento Ambiental , Acidificação dos Oceanos
16.
Biology (Basel) ; 12(6)2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-37372096

RESUMO

Microplastics represent an ever-increasing threat to aquatic organisms. We merged data from two global scale meta-analyses investigating the effect of microplastics on benthic organisms' and fishes' functional traits. Results were compared, allowing differences related to vertebrate and invertebrate habitat, life stage, trophic level, and experimental design to be explored. Functional traits of aquatic organisms were negatively affected. Metabolism, growth, and reproduction of benthic organisms were impacted, and fish behaviour was significantly affected. Responses differed by trophic level, suggesting negative effects on trophic interactions and energy transfer through the trophic web. The experimental design was found to have the most significant impact on results. As microplastics impact an organism's performance, this causes indirect repercussions further up the ecological hierarchy on the ecosystem's stability and functioning, and its associated goods and services are at risk. Standardized methods to generate salient targets and indicators are urgently needed to better inform policy makers and guide mitigation plans.

17.
Sci Rep ; 13(1): 22328, 2023 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-38102199

RESUMO

The Agronomic Revolution of the early Cambrian refers to the most significant re-structuration of the benthic marine ecosystem in life history. Using a global compilation of trace-fossil records across the Ediacaran-Cambrian transition, this paper investigates the relationship between the benthos and depositional environments prior to, during, and after the Agronomic Revolution to shed light on habitat segregation via correspondence analysis. The results of this analysis characterize Ediacaran mobile benthic bilaterians as facies-crossing and opportunistic, with low levels of habitat specialization. In contrast, the Terreneuvian and Cambrian Series 2 reveal progressive habitat segregation, parallel to matground environmental restriction. This event was conducive to the establishment of distinct endobenthic communities along the marine depositional profile, showing that the increase in styles of animal-substrate interactions was expressed by both alpha and beta ichnodiversity. Habitat segregation at the dawn of the Phanerozoic may illustrate an early extension of the trophic group amensalism at community scale.


Assuntos
Evolução Biológica , Ecossistema , Biologia Marinha , Animais , Fósseis
18.
Sci Rep ; 13(1): 22753, 2023 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-38123596

RESUMO

Trace fossils from Ordovician deep-marine environments are typically produced by a shallow endobenthos adapted to live under conditions of food scarcity by means of specialized grazing, farming, and trapping strategies, preserved in low-energy intermediate to distal zones of turbidite systems. High-energy proximal zones have been considered essentially barren in the early Paleozoic. We report here the first trace and body fossils of lingulide brachiopods in deep-marine environments from an Upper Ordovician turbidite channel-overbank complex in Asturias, Spain. Body and trace fossils are directly associated, supporting the interpretation of a lingulide tracemaker. Ellipsoidal cross-section, cone-in-cone spreite, and spade morphologies suggest the specimens belong to Lingulichnus verticalis. The oblique orientation in both trace and body fossils is the result of tectonic deformation. The organisms were suspension feeders showing escape, dwelling, and equilibrium behaviours controlled by sedimentation rates associated with turbidite deposition. These trace fossils and their in situ producers represent the oldest evidence of widespread endobenthos colonization in high-energy, proximal areas of turbidite systems, expanding the bathymetric range of Lingulichnus and the variety of behaviours and feeding styles in early Paleozoic deep-marine environments.


Assuntos
Fósseis , Invertebrados , Animais , Espanha
19.
Proc Biol Sci ; 279(1733): 1613-20, 2012 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-22072605

RESUMO

The first arthropod trackways are described from the Middle Cambrian Burgess Shale Formation of Canada. Trace fossils, including trackways, provide a rich source of biological and ecological information, including direct evidence of behaviour not commonly available from body fossils alone. The discovery of large arthropod trackways is unique for Burgess Shale-type deposits. Trackway dimensions and the requisite number of limbs are matched with the body plan of a tegopeltid arthropod. Tegopelte, one of the rarest Burgess Shale animals, is over twice the size of all other benthic arthropods known from this locality, and only its sister taxon, Saperion, from the Lower Cambrian Chengjiang biota of China, approaches a similar size. Biomechanical trackway analysis demonstrates that tegopeltids were capable of rapidly skimming across the seafloor and, in conjunction with the identification of gut diverticulae in Tegopelte, supports previous hypotheses on the locomotory capabilities and carnivorous mode of life of such arthropods. The trackways occur in the oldest part (Kicking Horse Shale Member) of the Burgess Shale Formation, which is also known for its scarce assemblage of soft-bodied organisms, and indicate at least intermittent oxygenated bottom waters and low sedimentation rates.


Assuntos
Artrópodes/fisiologia , Fósseis , Locomoção/fisiologia , Animais , Artrópodes/anatomia & histologia , Canadá
20.
PeerJ ; 10: e13869, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36032952

RESUMO

The Chengjiang biota (Yunnan Province, China) is a treasure trove of soft-bodied animal fossils from the earliest stages of the Cambrian explosion. The mechanisms contributing to its unique preservation, known as the Burgess Shale-type preservation, are well understood. However, little is known about the preservation differences between various animal groups within this biota. This study compares tissue-occurrence data of 11 major animal groups in the Chengjiang biota using a probabilistic methodology. The fossil-based data from this study is compared to previous decay experiments. This shows that all groups are not equally preserved with some higher taxa more likely to preserve soft tissues than others. These differences in fossil preservation between taxa can be explained by the interaction of biological and environmental characteristics. A bias also results from differential taxonomic recognition, as some taxa are easily recognized from even poorly preserved fragments while other specimens are difficult to assign to higher taxa even with exquisite preservation.


Assuntos
Evolução Biológica , Biota , Animais , China , Probabilidade , Fósseis
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