Multiple phyla, one time resolution? Similar time averaging in benthic foraminifera, mollusk, echinoid, crustacean, and otolith fossil assemblages

Geology, Год журнала: 2022, Номер 50(8), С. 902 - 906

Опубликована: Май 9, 2022

Abstract Time averaging of fossil assemblages determines temporal precision paleoecological and geochronological inferences. Taxonomic differences in intrinsic skeletal durability are expected to produce mismatch between co-occurring species, but the importance this effect is difficult assess due lack direct estimates time for many higher taxa. Moreover, burial below taphonomic active zone early diagenetic processes may alleviate taxonomic disintegration rates subsurface sediments. We compared across five phyla major carbonate producers a sediment core from northern Adriatic Sea shelf. dated individual bivalve shells, foraminiferal tests, tests isolated plates irregular regular echinoids, crab claws, fish otoliths. In spite different architecture, mineralogy, life habit, all taxa showed very similar varying ~1800 ~3600 yr (interquartile age ranges). Thus, remains echinoids crustaceans—two groups with multi-elemental skeletons assumed have low preservation potential—can still undergo extensive mixing comparable that mollusk shells. The median ages differed by as much ~3700 yr, reflecting species-specific timing seafloor colonization during Holocene transgression. Our results congruent sequestration models invoking minimize among These together variability production can overrule effects determining resolution multi-taxic assemblages.

Язык: Английский

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Ecological regime shift preserved in the Anthropocene stratigraphic record

Proceedings of the Royal Society B Biological Sciences, Год журнала: 2020, Номер 287(1929), С. 20200695 - 20200695

Опубликована: Июнь 17, 2020

Palaeoecological data are unique historical archives that extend back far beyond the last several decades of ecological observations. However, fossil record continental shelves has been perceived as too coarse (with centennial-millennial resolution) and incomplete to detect processes occurring at yearly or decadal scales relevant ecology conservation. Here, we show youngest (Anthropocene) on northern Adriatic shelf provides decadal-scale resolution accurately documents an abrupt change affecting benthic communities during twentieth century. The magnitude duration century shift in body size bivalve Corbula gibba is unprecedented given regional populations this species were dominated by small-size classes throughout Holocene. coincided with compositional changes assemblages, driven increase from approximately 25% 70% median per-assemblage abundance C. gibba. This regime occurred preferentially sites experienced least one hypoxic event per decade Larger higher probably reflect release it coincides frequency seasonal hypoxia triggered mass mortality competitors predators. Higher events coupled a decline depth intense sediment mixing burrowing organisms decimetres less than 20 cm, significantly improving stratigraphic Anthropocene making possible sub-centennial shelves.

Язык: Английский

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Temporal scales, sampling designs and age distributions in marine conservation palaeobiology

Geological Society London Special Publications, Год журнала: 2023, Номер 529(1), С. 1 - 39

Опубликована: Март 29, 2023

Abstract Conservation palaeobiology informs conservation and restoration of ecosystems by using the fossil record to discriminate between baseline novel states assess ecosystem response perturbations. Variability in time-scale palaeobiological data can generate patterns that either exaggerate or mute magnitude biotic changes. We identify two approaches remedy challenges associated with mixing post-impact transformation stratigraphic depth time. First, combining surface death assemblages both (1) preserved subsurface historical layers (2) living better resolve nature shifts than within-core surveys live–dead analyses alone. Second, post-mortem age distributions skeletal particles their preservation are not only informative about resolution time averaging but also timing changes abundance producers. High youngest cohorts is a null expectation disintegration burial dynamic. When this dynamic accounted for, benthic invertebrates from Holocene sediments often reveal high volatility, prolonged turn-offs production pervasive regime obscured raw record.

Язык: Английский

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Millennial‐Scale Age Offsets Within Fossil Assemblages: Result of Bioturbation Below the Taphonomic Active Zone and Out‐of‐Phase Production

Paleoceanography and Paleoclimatology, Год журнала: 2019, Номер 34(6), С. 954 - 977

Опубликована: Май 13, 2019

Abstract Oceanographic and evolutionary inferences based on fossil assemblages can be obscured by age offsets among co‐occurring shells (i.e., time averaging). To identify the contributions of sedimentation, mixing, durability, production to within‐ between‐species offsets, we analyze downcore changes in age‐frequency distributions two bivalves California shelf. Within‐species are ~50–2,000 years for Parvilucina ~2,000–4,000 Nuculana 1,000–4,000 within 10‐ 25‐cm‐thick stratigraphic units. Shells top 20–24 cm seabed age‐homogeneous, defining thickness surface completely‐mixed layer (SML), have strongly right‐skewed distributions, indicating fast shell disintegration. The SML thus coincides with taphonomic active zone extends below redoxcline at ~10 cm. >2,000–3,000 old occurring been exhumed from subsurface shell‐rich units rich where disintegration is negligible (sequestration zone, SZ). Burrowers (callianassid shrimps) penetrate 40–50 seafloor into this SZ. millennial each increment result advection SZ, combined an out‐of‐phase change species production. Age unmixing reveals that was abundant during transgressive phase, rare highstand increased steeply twentieth century response wastewater. phase has declined over past centuries. This sequestration‐exhumation dynamic accentuates allowing both persistence their later admixing younger SML.

Язык: Английский

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CHALLENGES OF CONSERVATION PALEOBIOLOGY: FROM BASELINES TO NOVEL COMMUNITIES TO THE NECESSITY FOR GRANTING RIGHTS TO NATURE

Palaios, Год журнала: 2023, Номер 38(6), С. 259 - 263

Опубликована: Июнь 23, 2023

Research Article| June 23, 2023 CHALLENGES OF CONSERVATION PALEOBIOLOGY: FROM BASELINES TO NOVEL COMMUNITIES THE NECESSITY FOR GRANTING RIGHTS NATURE MARTIN ZUSCHIN Department of Paleontology, University Vienna, Josef-Holaubek-Platz 2, 1090 Austria email: [email protected] Search for other works by this author on: GSW Google Scholar Author and Article Information Publisher: SEPM Society Sedimentary Geology Received: 17 May Accepted: 24 First Online: 27 Jun Online ISSN: 1938-5323 Print 0883-1351 Copyright © 2023, (Society Geology) PALAIOS (2023) 38 (6): 259–263. https://doi.org/10.2110/palo.2023.020 history Cite View This Citation Add to Manager Share Icon Facebook Twitter LinkedIn Email Permissions Site ZUSCHIN; NATURE. 2023;; doi: Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Dropdown Menu input auto suggest filter your All ContentBy SocietyPALAIOS Advanced Conservation Paleobiology (CP) was formally introduced more than 20years ago (Flessa 2002) as a field that deals with the application theories analytical tools paleontology biodiversity conservation, but has multifaceted roots go back at least into 1970s (Dietl Flessa 2009; Dillon et al. 2022). More thirty years ago, it already evident anthropogenic impacts had changed modern marine environments so profoundly ecological research alone does not catch undisturbed baselines (e.g., Pauly 1995; Jackson 1997; 2001; Kowalewski Pandolfi et... You do have access content, please speak institutional administrator if you feel should access.

Язык: Английский

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Inferring time averaging and hiatus durations in the stratigraphic record of high‐frequency depositional sequences

Sedimentology, Год журнала: 2021, Номер 69(3), С. 1083 - 1118

Опубликована: Авг. 22, 2021

Abstract A sequence stratigraphic framework predicts that time averaging and hiatus durations will be long at times of fastest sea‐level rise. This prediction does not necessarily apply to environments where carbonate production keeps up with rise undetected hiatuses decouple short‐term from long‐term sedimentation rates. The taphonomic clock, however, which measures the residence skeletal particles in mixed layer, can estimate duration if rate alteration is slow endure exposure layer. Here, calibrated by using evidence bivalves a metre‐scale Holocene Adriatic Sea. In this sequence, transgressive molluscan lags, maximum‐flooding zone shell bed bivalves, highstand bryomol assemblages were all deposited under similar rates ( ca 0.01 0.03 cm year −1 ) exhibit millennial averaging. Median ages valves stained pyrite cemented high‐magnesium calcitic micritic envelopes exceeding 1000 years indicate that: (i) these authigenic processes are subsurface zones reducing conditions (with prolonged sulphate reduction ions sourced dissolved shells surface zones); (ii) micrite precipitation prolongs disintegration half‐lives exhumed decades millennia. high abundance valves, envelopes, composite (encrusters borers colonizing grains) thus identifies concentrations time‐averaged >1000 years. upcore decrease alteration, coupled temporally‐constant averaging, indicates temporal decline sediment exhumation was compensated burial produced molluscs.

Язык: Английский

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TRACING ORIGIN AND COLLAPSE OF HOLOCENE BENTHIC BASELINE COMMUNITIES IN THE NORTHERN ADRIATIC SEA

Palaios, Год журнала: 2019, Номер 34(3), С. 121 - 145

Опубликована: Март 1, 2019

The shallow northern Adriatic Sea has a long history of anthropogenic impacts that reaches back many centuries. While the effects eutrophication, overfishing, pollution, and trawling over recent decades have been extensively studied, major ecological turnovers during Holocene as whole remain poorly explored. In this study, we reconstruct baselines defining benthic ecosystem composition prior to changes at four stations characterized by low sedimentation millennial-scale time averaging molluscan assemblages. We discriminate between natural drivers based on (1) stratigraphic in communities observed sediment cores (2) concentrations heavy metals, pollutants, organic enrichment. 1.5-m reach Pleistocene–Holocene boundary, allowing for distinction sea-level phases Holocene. During transgressive phase maximum flooding, establishment modern circulation pattern determined development shallow-water, vegetated habitats with epifaunal biostromes and, deeper waters, bryozoan meadows. After stabilization, these baseline remained relatively uniform started change markedly only intensification human late highstand, leading dominance infauna decline epifauna all sites. This profound reduced species richness, increased abundance infaunal suspension feeders, led grazers deposit feeders. suggest soft-bottom today do not show high geographic heterogeneity characteristic benthos influences.

Язык: Английский

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Assessing biotic response to anthropogenic forcing using mollusc assemblages from the Po–Adriatic System (Italy)

Geological Society London Special Publications, Год журнала: 2022, Номер 529(1), С. 293 - 310

Опубликована: Дек. 22, 2022

Abstract Preserving the adaptive capacities of coastal ecosystems in Anthropocene requires an understanding their natural variability prior to modern times. We quantified responses nearshore molluscs assemblages past environmental changes using 101 samples ( c. 57 300 specimens) retrieved from subsurface Holocene succession and present-day seabed Po–Adriatic System (Italy). Present-day shifted faunal composition with respect mid-late counterparts. Major differences are observed lower settings, where show higher heterogeneity, reduced standardized richness, relative abundance Lentidium mediterraneum, increased Varicorbula gibba , scavengers (genus Tritia ), deposit feeders (nuculid bivalves). A dominance infaunal opportunistic species shifts towards detritus-feeding scavenging often associated disturbed benthic habitats. Our results suggest that ongoing anthropogenic stressors (mainly bottom trawling non-native species) currently shifting communities into novel states outside range archived fossil record. Supplementary material: document containing additional statistics, figures, tables, also considering different filters applied molluscan dataset, is provided as a Word file. In addition, appendices concerning sample taxa information R-scripts .csv .r files. These available at https://doi.org/10.6084/m9.figshare.c.6351348

Язык: Английский

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Resource partitioning among brachiopods and bivalves at ancient hydrocarbon seeps: A hypothesis

PLoS ONE, Год журнала: 2019, Номер 14(9), С. e0221887 - e0221887

Опубликована: Сен. 5, 2019

Brachiopods were thought to have dominated deep-sea hydrothermal vents and hydrocarbon seeps for most of the Paleozoic Mesozoic, believed been outcompeted replaced by chemosymbiotic bivalves during Late Cretaceous. But recent findings bivalve-rich seep deposits Mesozoic age questioned this paradigm. By tabulating generic diversity dominant brachiopod bivalve clades–dimerelloid brachiopods bivalves–from through Phanerozoic, we show that their evolutionary trajectories are largely unrelated one another, indicating they not competing same resources. We hypothesize dimerelloid generally preferred with abundant hydrocarbons in bottom waters above seep, such as oil or methane diffusive seepage, whereas strong, advective fluid flow hence hydrogen sulfide less favorable them. At typified seepage seeps, oxidation water chemotrophic bacteria enhances growth bacterioplankton, on which could filter fed. Whereas mostly relied sulfide-oxidizing symbionts nutrition, aerobic bacterial other played a more prominent role. The availability geofuels (i.e. reduced chemical compounds used chemosynthesis sulfide, methane, hydrocarbons) at is governed rates, geological setting, marine sulfate concentrations. Thus rather than competition, suggest geofuel type controlled distribution Phanerozoic.

Язык: Английский

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Radiocarbon dating supports bivalve-fish age coupling along a bathymetric gradient in high-resolution paleoenvironmental studies

Geology, Год журнала: 2020, Номер 48(6), С. 589 - 593

Опубликована: Март 27, 2020

Abstract Studies of paleocommunities and trophic webs assume that multispecies assemblages consist species coexisted in the same habitat over duration time averaging. However, even with similar durability can differ age within a single fossil assemblage. Here, we tested whether skeletal remains different phyla guilds, most abundant infaunal bivalve shells nektobenthic fish otoliths, differed radiocarbon surficial sediments along depth gradient from 10 to 40 m on warm-temperate Israeli shelf, modeled their dynamics taphonomic loss. We found that, spite higher potential fishes for out-of-habitat transport after death, differences structure depths were smaller by almost an order magnitude than between depths. Shell otolith underwent depth-specific burial pathways independent taxon identity, generating death comparable averaging, supporting assumption temporal spatial co-occurrence mollusks fishes.

Язык: Английский

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