Molluscan Assemblages Research Articles

Sclerochronology and oxygen isotope variations in modern Conomurex luhuanus shells: An archive for reconstructing palaeotemperature and shellfish gathering on the Great Barrier Reef, Australia

The marine gastropod Conomurex luhuanus is a common component of Holocene archaeological shell deposits in the Western Indo-Pacific region. Oxygen isotope ratios recorded in shells of C. luhuanus from the Great Barrier Reef potentially provide high-resolution data on palaeoclimatic conditions and the exploitation of coastal marine resources. However, the application of this species as a palaeoclimate and seasonal foraging archive has yet to be investigated. We employ sclerochronology techniques to analyse oxygen isotope variations in modern, live-collected shells to evaluate the efficacy of this species in recording modern environmental factors, such as sea-surface temperature (SST). We collected live C. luhuanus during the cold season (August and September), in two separate years (2019 and 2023), from reef-flat intertidal zones. Shell growth increments were studied in section and high-resolution carbonate samples were collected from the lip portion and along the body whorl to test whether shell carbonate is deposited in oxygen isotopic equilibrium with seawater and to decipher the shell growth pattern of this species. Measured δ18Oshell ranges between −0.2 and − 1.8 ‰ (VPDB) in modern samples. Despite showing variability in growth rates, including a remarkable growth stop/slowdown during the cool season that is punctuated by a red zone with closely spaced growth increments, our findings reveal that C. luhuanus deposits its aragonite shells at (or close to) equilibrium with its surrounding environment. When sampled at high resolution (sub-seasonally), oxygen isotopes can be used to reconstruct the full annual SST range. The estimated SSTs closely match the range of instrumental SSTs measured in the study area, whilst the last deposited (edge) shell-calculated SST can be used to determine the season of animal death. This study shows that well-preserved shells of C. luhuanus can serve as excellent high-resolution palaeotemperature archives for the tropical reef-flat zone. This research underpins the use of this species in future research to determine human-environment interactions and reconstruction of palaeoclimate from archaeological and fossil samples in the Western Pacific Ocean.

Beyond hinges and spires: A critical examination of archaeomalacological quantification methodologies using coral reef molluscan assemblages from Jiigurru (Lizard Island Group), northern Great Barrier Reef

Quantification, as one of the pillars of the zooarchaeological subdiscipline, is an invaluable component of the toolkit researchers use to study past people-animal interactions. Despite being the subject of rigorous (zoo)archaeological debate, the calculation of Minimum Number of Individuals (MNI) values remains one of the main methods of quantifying the relative abundance of taxa within faunal assemblages. Choosing the appropriate quantification protocol to calculate the MNI of archaeological invertebrate assemblages can be challenging due to regional taxonomic considerations and the myriad of quantification methodologies and frameworks available in the global archaeomalacological literature. In an Australian context, methodologies for quantifying coral reef molluscan assemblages have not been explicitly evaluated. Using archaeological molluscan assemblages from two midden sites (Freshwater Bay Midden and Mangrove Beach Headland Midden) on the northern Great Barrier Reef island group of Jiigurru (the Lizard Island Group), we critically examine two commonly adopted archaeomalacological quantification methodologies: the NRE MNI and tMNI protocols. The NRE MNI methodology uses one to two non-repetitive elements (NREs) of molluscs, whilst the tMNI protocol includes a wider range of elements akin to vertebrate MNI quantification methodologies. Through a comparison of taxa abundances and statistical analyses, results show that the tMNI protocol, with some modification, is best suited for the Jiigurru assemblages. Higher MNI values and an increased assemblage diversity, evenness, and richness were recorded for the molluscan assemblages at both midden sites when the tMNI protocol was applied. This study foregrounds the importance of data transparency when reporting quantification protocols and outcomes to ensure the highest degree of data quality, replicability, and usability.

Correction: Comparative effects of river–lake disconnection on taxonomic and functional composition of molluscan assemblages in floodplain lakes

Correction: Comparative effects of river–lake disconnection on taxonomic and functional composition of molluscan assemblages in floodplain lakes

Human-driven breakdown of predator-prey interactions in the northern Adriatic Sea.

Long-term baseline data that allow tracking how predator-prey interactions have responded to intensifying human impacts are often lacking. Here, we assess temporal changes in benthic community composition and interactions between drilling predatory gastropods and their molluscan prey using the Holocene fossil record of the shallow northern Adriatic Sea, which is characterized by a long history of human transformation. Molluscan assemblages differ between the Isonzo and Po prodelta, but both show consistent temporal trends in the abundance of dominant species. Samples of mollusc prey collected at high stratigraphic resolution indicate that drilling frequencies have drastically declined in the Po prodelta since the mid-twentieth century, while a weaker trend in the more condensed sediments of the Isonzo prodelta is not statistically significant. The decrease in drilling predation intensity and the community turnover are linked to the loss of predatory gastropods and the increased relative abundance of less-preferred prey during the most recent decades. Our results align with data showing the substantial depletion of marine resources at higher trophic levels in the region and indicate that the strong simplification of the food web initiated in the late nineteenth century accelerated further since the mid-twentieth century.

Late Quaternary history of the Kerch Strait — the stratotype region for the Black Sea

The Kerch Strait has periodically connected to the Black, Azov, and Caspian seas throughout its Late Quaternary history. The strait's deposits reflect the changes in the natural environment of the entire Ponto-Caspian region, which are a response to global climate change. Several studies have been done on the region's stratigraphy, biostratigraphy, geomorphology, and paleogeography. However, most of the current knowledge about the paleogeography of the area is based on the analysis of empirical data collected more than 25 years ago, and due to the lack of detailed geochronological studies, many palaeogeographical problems remain unresolved.This paper presents a reconstruction of environmental change in the Kerch Strait during the Late Quaternary. The reconstruction is based on the results of a comprehensive study of the sedimentary sequences in the Kerch Strait carried out by the author and colleagues over the past ten years. The study examines the deposits of two stratotype sections of the Karangatian (Eemian) transgression and the four boreholes’ sections in Tuzla Island in the central part of the strait.A biostratigraphic division of the Upper Quaternary deposits of the Kerch Strait was carried out based on a malacofaunal study. Mollusc assemblages corresponding to various paleogeographic stages of development were identified, and their paleoecological characteristics were described. Luminescence and radiocarbon ages made it possible to determine the time intervals of established paleogeographic stages in the strait's history. Detailed luminescence dating of the Karangatian transgression sediments of the Eltigen and Tuzla stratotype sections has been carried out for the first time.Six main stages in the Kerch Strait natural environment development were established in the Late Quaternary and correlated with global and regional climatic events: Karangatian, with three stages (MIS 5e-c); Tarkhankutian (MIS 5a); Post-Karangatian (MIS 4); Surozh (MIS 3); Neoeuxinian, with two stages (MIS 2); and Chernomorian (MIS 1). Two episodes of the Caspian waters flowing through the Kerch Strait into the Black Sea were identified in MIS 5c and at the end of MIS 2.

Comparative effects of river–lake disconnection on taxonomic and functional composition of molluscan assemblages in floodplain lakes

Comparative effects of river–lake disconnection on taxonomic and functional composition of molluscan assemblages in floodplain lakes

Multiproxy faunal analysis of the middle – upper Eocene deposits in the Fayum area, Egypt: Insights into sequence stratigraphy, trophic conditions, and oxygenation

The Eocene epoch experienced significant fluctuations in climate, ranging from intense greenhouse warming to icehouse cooling, which profoundly impacted the global depositional systems. The middle – upper Eocene deposits in Garet Gehannam, Fayum area, Egypt, present an exciting opportunity to explore paleoenvironmental dynamics using a multiproxy dataset of calcareous nannofossils, benthic foraminifera, ostracods, and molluscan assemblages. Calcareous nannofossil biostratigraphy constrained the studied sequence to the NP17 and NP-19-20 zones. Furthermore, three 3rd-order depositional sequences, BAR.SQ.1, BAR.SQ.2, and PR.SQ.3 were identified. The BAR.SQ.1 sequence encompasses the Gehannam Formation, with a transgressive systems tract (TST) and a highstand systems tract (HST). The BAR.SQ.2 sequence corresponds to the lower Birket Qarun Formation and exhibits a TST/HST pattern. The PR.SQ.3 sequence, however, consists solely of a TST spanning the upper Birket Qarun and Qasr El Sagha formations. The main trend of our multiproxy-based sea level curve shows an overall stepped Tethyan sea level regression within the 2nd-order cycle. This regression is characterized by a transition from outer neritic to inner settings, interrupted by two minor 3rd-order transgressive pulses. This sea level trend was likely driven by global eustatic changes and regional tectonic uplift related to the final collisional phase between Africa/Arabia and Eurasia, which led to the closure of the Neotethys Ocean. Multiproxy faunal analysis reveals a pronounced upsection shift from low-oxic and mesotrophic conditions to well-ventilated, oligotrophic settings tracking long-term sea level fall. The lowering of the sea level may have expanded aerobic ventilation windows on the continental shelf while potentially reducing nutrient influx. Our multiproxy sequence stratigraphic and paleoenvironmental analysis provides insights into the complex interplay of tectonic, eustatic, and climatic influences on the region during the middle – late Eocene episode along the southern Tethyan margin.

The response of epibenthic molluscan assemblages associated with Mytilus galloprovincialis beds to natural- and human-induced changes: Structure and small-scale spatiotemporal variability

Mussel beds are species-rich and diversified biogenic habitats for associated assemblages, playing important ecological roles and contributing significantly to local littoral invertebrate biodiversity. The community structure and seasonal patterns of molluscan assemblages associated with rocky-intertidal mussel Mytilus galloprovincialis beds along NW Atlantic coast of Morocco were investigated. Sampling was conducted at reference and contaminated stations in three distant coastal areas over a 4-season sampling period (between August 2018 and May 2019). We tested the hypothesis that the biogenic mussel habitats in areas experiencing different environmental conditions along the shore would support different associated molluscan assemblages under human-induced and natural changes at small spatial and temporal scales. A total of 6371 specimens comprising 28 taxa were identified and encompassing four trophic groups (carnivores, detritivores/deposivores, micrograzers and suspensivores). Micrograzers predominated, followed by carnivores, with gastropods being the numerically dominant taxa accounting for 79 % of total abundance. Steromphala pennanti emerged as the most abundant and frequent species, across almost all seasons and stations contributing to 31 % of total abundance. Significant seasonal variations were observed in species richness and Shannon-Wiener’s index (ANOVA, p<0.05), with the highest values recorded at the most polluted stations during cold/wet periods, and the lowest at the cleanest stations during hot/warm periods. Furthermore, the ANOVA analyses unveiled a significant spatiotemporal variation in abundance, emphasizing the dynamic nature of molluscan assemblages in response to environmental conditions and seasonal changes. The multivariate structure of associated molluscan assemblages (PERMANOVA analysis) differed significantly among stations and seasons, highlighting clear geographical and seasonal effects. Gastropod species, including Acanthochitona fascicularis, Lepidochitona cinerea, Nucella lapillus, Patella ulyssiponensis, P. vulgata, Phorcus lineatus, P. sauciatus, and Steromphala pennanti, were identified as the most contributive species to the dissimilarity of molluscan assemblage structure among stations throughout seasons (SIMPER analysis). Based on the canonical correspondence analysis results, salinity, water temperature, nutrient concentrations, sediment granulometry and total organic matter were identified as the key factors driving changes in the molluscan community structure. This study underscores the ecological importance of habitat-forming mussels as ecosystem engineers and biodiversity enhancers in shallow coastal waters along the Moroccan Atlantic coast.

Late Middle Pleistocene (MIS 10–6) glacial–interglacial records from loess–palaeosol and fluvial sequences from northern France: a cyclostratigraphic approach

This contribution summarizes the most informative loess–palaeosol sequences (LPS) and fluvial terrace records from the late Middle Pleistocene (LMP) of northern France demonstrating the reliability of the cyclostratigraphic approach for the interpretation of pedosedimentary sequences controlled by major glacial–interglacial climatic cycles. In this area, continental mollusc assemblages from interglacial fluvial silts and calcareous tufas are particularly rich and diverse and marker species define the malacological signatures of each interglacial optimum for Marine Isotope Stages (MIS) 11, 9 and 5e. This approach shows that the forest was less developed during MIS 7, suggesting that climatic conditions were either drier and/or cooler than during other Pleistocene interglacials. In the Somme basin, the terrace system shows that two alluvial formations were deposited between early MIS 8 and late MIS 7. In some LPS, the occurrence of two pedosedimentary sub‐cycles (IIa and IIb), separated by a relatively long (~12 ka) and cold period, corresponding to an ‘aborted glacial’ (MIS 7d), underlines the complex pattern of this unusual ‘interglacial’. Overall, during the LMP, each soil complex corresponding to interglacial and early‐glacial periods from MIS 11 to MIS 5 is broadly made up of the same soil facies but exhibits a specific succession pattern or signature. Throughout the area, LPS show a huge change in both the deposition rates and the geographical extent of typical calcareous loess at the beginning of MIS 6. This so‐called ‘Loess Revolution’ probably reflects a change in the palaeogeography of the southern North Sea and eastern Channel source areas at times marked by the coalescence of the British and Scandinavian ice sheets. MIS 6 is also characterized by the oldest evidence of permafrost development in the area. In addition, this work allows the age of the Lower/Middle Palaeolithic boundary to be confirmed, with the oldest occurrence of Levallois technology being around 300 ka.

Late Miocene mollusks from the Dar Pahn Unit, Makran, SE Iran

Diverse, abundant and well-preserved mollusk fauna are here reported for the first time from the eastern coast Makram area, where Upper Miocene (Tortonian) sediments of the Dar Pahn Unit crop out, representing shoreface tidal influenced deposits composed mainly of ligh-gray marls. Multiple articulated bivalves and completely preserved the gastropod and bivalve shells indicate little or no transport at all from the original habitat of the mollusk assemblage. A total of 313 specimens, from which 271 correspond to gastropods, were identified only at generic level, since the purpose of this contribution is to offer an introduction to this exceptionally well-preserved mollusk assemblage. Previous studies of the area include detailed nannoplankton biostratigraphy and the report of a balaenopterid cetacean. Future studies include the detailed identification of the specimens, along with sediment analysis in order to find protoconchs and offer an extended version of this introductory report.

NEW GEOLOGICAL AND PALAEONTOLOGICAL DATA OF THE DYAKOVE GROUP (CARBONIFEROUS) AND AGE-RELATED ROCK FORMATIONS OF THE CENTRAL DONETS BASIN, UKRAINE

New finds of fossil assemblages of brachiopods, mollusks, crinoids, arthropods and fishes, as well as terrestrial plants from a part of the Dyakove Group, which corresponds to the coal-bearing Mandrykyne Formation and the lower part of the Mospyne Formation and is exposed in the southern part of the Luhansk Region, were studied. For the first time, a brachiopod assemblage consisting of species of the genera Crurithyris, Tiramnia, Alphachoristites, Lissochonetes were identified in these rocks. In addition, phyllocarids and impressions of terrestrial plants of the genera Halonia, Calamites, Pinnularia, Paripteris, Eusphenopteris, Artisia and Cordaites were found in the Dyakove Group for the first time. Bivalves and gastropods in the studied collection are represented by the genera Phestia, Palaeoneilo, Nuculavus, Solenomorpha, Sanguinolites, Posidoniella, ?Euchondria, ?Nodospira, Euphemites, Retispira, Glabrocingulum, Rhineoderma, Angyomphalus, and Naticopsis. Cephalopods are represented by the species of the genera Gzheloceras, ?Pseudogzheloceras, Melvilloceras, Retites, Gastrioceras and ?Owenoceras. In addition to the above groups, the rocks also contain the crinoids Platyplateium, Platycrinites, ?Unilineatocrinus and Bicostulatocrinus as well as fragments of fin spines of acanthodians Gyracanthidae indet. and isolated unidentified fish scales.

A Late Pleistocene coastal ecosystem in French Guiana was hyperdiverse relative to today

Warmer temperatures and higher sea level than today characterized the Last Interglacial interval [Pleistocene, 128 to 116 thousand years ago (ka)]. This period is a remarkable deep-time analog for temperature and sea-level conditions as projected for 2100 AD, yet there has been no evidence of fossil assemblages in the equatorial Atlantic. Here, we report foraminifer, metazoan (mollusks, bony fish, bryozoans, decapods, and sharks among others), and plant communities of coastal tropical marine and mangrove affinities, dating precisely from a ca. 130 to 115 ka time interval near the Equator, at Kourou, in French Guiana. These communities include ca. 230 recent species, some being endangered today and/or first recorded as fossils. The hyperdiverse Kourou mollusk assemblage suggests stronger affinities between Guianese and Caribbean coastal waters by the Last Interglacial than today, questioning the structuring role of the Amazon Plume on tropical Western Atlantic communities at the time. Grassland-dominated pollen, phytoliths, and charcoals from younger deposits in the same sections attest to a marine retreat and dryer conditions during the onset of the last glacial (ca. 110 to 50 ka), with a savanna-dominated landscape and episodes of fire. Charcoals from the last millennia suggest human presence in a mosaic of modern-like continental habitats. Our results provide key information about the ecology and biogeography of pristine Pleistocene tropical coastal ecosystems, especially relevant regarding the-widely anthropogenic-ongoing global warming.

Měkkýši národní přírodní rezervace Jazevčí v CHKO Bílé Karpaty [Molluscs of Jazevčí National Nature Reserve in the White Carpathians PLA

The Jazevčí National Nature Reserve is located in the southern part of the White Carpathians PLA near the Javorník nad Veličkou village. The reserve protects a heterogeneous landscape with meadows, groves, springs, and creeks. This diversity is reflected in the mollusc assemblages, which contain nine out of ten ecological groups. In total, 58 mollusc species are known from the reserve, 56 being terrestrial gastropods with one aquatic snail and one bivalve. Most diversity consists of forest species, followed by the euryvalent and hygrophilous species. Three species are listed in the Red List of Threatened Species: Daudebardia brevipes (VU), Bythinella austriaca (NT), and Vertigo angustior (VU), the latter also being internationally protected under Annex II of the EU Habitats Directive. Vertigo angustior was found in a deciduous forest, a habitat highly unusual for this species. Trochulus villosulus, a rare species, was found in a wet meadow near the Velička stream. As most species diversity is found in groves and forests, a non-intervention regime is suggested to retain their species diversity, while meadows should be managed extensively by kettle grazing or mowing.

Investigating the Upper Holocene palaeoenvironment and human subsistence strategy in the Khor Rori coastal area by studying mollusc remains from the Inqitat plateau (Dhofar, Sultanate of Oman)

ABSTRACTArchaeological shells have a great potential for reconstructing past environments and human–environment interactions. The Inqitat plateau (Khor Rori Archaeological Park, Oman) shows rich mollusc assemblages, present in the HAS1 settlement and in a shell midden nearby (Iron Age). By analysing the environmental requirements of the species identified in the assemblages, we reconstruct the past coastal environment and investigate its exploitation by the local population and human activities during the settlement occupation. This is the first multidisciplinary investigation of Iron Age molluscs from Dhofar. Our results indicate that the environment surrounding the site was characterised by rocky shores and shallow‐water sandy to sandy‐muddy substrates, where locals collected shells. Mangrove species were recovered in few numbers, indicating that this environment was restricted or not exploited. Furthermore, a different use of shells between circular houses within the settlement and the midden was observed; in the former, species used as ornaments are more abundant, whereas, in the latter, species used for food purposes are found, confirming the primary use of the midden as a dump. The presence of easily accessible settings for mollusc collection in the site's vicinity and the richness in food resources due to a coastal upwelling makes this region very attractive for human populations.

Late Pleistocene (MIS-2–MIS-4) mollusc assemblages of the loess-palaeosol sequence in Zalesie near Przemyśl (southern Poland)

Late Pleistocene (MIS-2–MIS-4) mollusc assemblages of the loess-palaeosol sequence in Zalesie near Przemyśl (southern Poland)

Predatory drilling on molluscan assemblages along the Patagonian shelf (southern Argentina)

Abstract Both present-day and fossil molluscan assemblages offer an opportunity for a better understanding of the structure and organization of both modern and past benthic communities. In this framework, drill holes are used widely to explore predator–prey interactions. This research focuses on predation marks, especially drill holes, recorded on modern molluscan assemblages in a Patagonian sector of the Argentinean continental shelf. Shelled molluscs (n = 2179) were recovered from 27 to 135 m depths covering a long latitudinal extent (between 39° and 54°S). For each station, taxonomic position, ecological composition and relative abundance of taxa were determined, and then drilling frequency (DF) was calculated to infer drilling intensity. The collected molluscs belong to 37 families, with Veneridae being the most abundant in terms of the number of specimens (n = 419). Specimens with drill holes (n = 226) belong to 21 families (with at least 33 different species). Most of them are suspension feeders (85.8%) and the remaining percentage comprised other trophic types. Naticids and muricids, as main potential predators, together account for 19.6% of the gastropods present in the molluscan assemblages. DF across all the stations was moderate (9.9%) but varied between low (0–2.4%) and high (28.9%). These results do not show a trend linked to latitude or depth, and the great variability of DF between stations suggests that other local ecological or environmental conditions would influence drilling predation at a small spatio-scale.

Reproductive biology of Donax striatus (Linnaeus, 1758) (Mollusca: Bivalvia) on Gado Bravo Beach, municipality of Tibau do Norte, state of Rio Grande do Norte, Brazil.

Aspects of the reproductive biology of Donax striatus were studied from individuals collected from Gado Bravo Beach in the municipality of Tibau do Norte, state of Rio Grande do Norte, Brazil. Donax striatus is a dioic species without external (on the shell) or internal (gonads) macroscopic dimorphism. Thus, a microscopic examination of the reproductive cells is necessary. For the characterization of the gonadal development stages and determination of the size at first sexual maturity (L50), 30 specimens were selected monthly between February 2021 and January 2022 and submitted to histological processing. The condition index (CI) of each individual was estimated and monthly variations were statistically assessed. The size at first maturity (L50) was estimated to be 14.2 mm in shell length. To foster conservation of the species, catches of individuals larger than 14.2 mm is recommended. The lowest condition indices were found in the dry season, with a greater occurrence of organisms in the elimination stage and exhibiting gonad tissue reorganization. Higher indices were found in the rainy season, with the presence of mature individuals. The continuous nature of gametogenesis in Donax stritatus reflects the influence of rainfall in the region. Males and females have peak gamete elimination with pauses during the year, but with the presence of maturing and eliminating individuals throughout the year. As shellfish gathering targeting Donax striatus is excessive on Gado Bravo Beach in the state of Rio Grande do Norte, it is hoped that the results of the present study can contribute to the establishment of management measures for the activity and conservation strategies for the species.

Middle Holocene Oyster Shells and the Shifting Role of History in Ecological Restoration: How a Dynamic Past Informs Shellfish Ecosystem Reconstruction at an Australian Urban Estuary

Abstract At Western Australia's Swan-Canning Estuary, extensive subfossil shellfish assemblages of Middle Holocene origin were largely destroyed through dredging for cement production in the first half of the twentieth century. This case-study of an extractive industry driving shellfish ecosystem decline builds on existing historical studies of commercial over-harvesting of oysters, and historical and paleo-ecological investigations of sustainable, long-term indigenous oyster harvests, presenting an important new perspective on global shellfish ecosystem decline and the enduring cultural value of shellfish resources by revealing processes of cross-cultural knowledge transfer, unfolding environmental understanding and extensive environmental change across Western Australia's post-European settlement history. We explore these histories in detail for the first time, before considering their relevance to a shellfish ecosystem reconstruction initiative currently underway at this major Australian urban estuary.

Continental mollusk assemblages from the Quaternary of Uruguay

Only a few studies on Quaternary continental mollusks of Uruguay have been published over the last few decades. Despite the high occurrence of this group in many of the Late Pleistocene outcrops of the country, all of them are better known for their classic Ice Age mammal assemblages. To overcome this situation, 23 localities were sampled from two lithostratigraphic units: the Sopas and Dolores formations. The identified species are included in the families Sphaeriidae, Cyprinidae, Mycetopoda, Acridae (freshwater bivalves); Ampullariidae, Cochliopidae, Tateidae, Chilina, Physidae, Planorbidae (freshwater gastropods); Scolodontidae, Succineidae, Charopidae and Bulimia (terrestrial gastropods). As a result of these new samplings, the Sopas Formation mollusk species count increased from 20 to 29 species, and the Dolores Formation from six to 29 species. Seventeen of these species are new records for the Quaternary of Uruguay, and eight for the Quaternary of South America. Two bivalves, five freshwater gastropods, and a new terrestrial gastropod were added for the Sopas Formation; and for the Dolores Formation, four new bivalves, 14 new freshwater gastropods, and five new terrestrial gastropods. The Dolores Formation has been the most understudied unit until now, increasing here its biodiversity to 23 species. These new records of freshwater and terrestrial gastropods, increase the biodiversity and biogeographical range of the continental mollusks of the Late Pleistocene-early Holocene of the region. In addition, new AMS 14C ages were obtained for both lithostratigraphic units, framing the age of the mollusk assemblages for both formations in the a maximum range of 13,000–48,000 years before the present.

Giant limpets in southern Iberian coastal and continental archaeological sites, from Neanderthals to Copper Age

The use of coastal resources has been crucial for human diet and social behaviour evolution has been extensively documented since the Middle Palaeolithic, mainly in the western Mediterranean and southern Africa. In southern Iberia, the mollusc assemblages associated with archaeological sites show a continuous record regardless of palaeoclimatic conditions. Among these, limpets are uninterruptedly abundant from the Middle Palaeolithic to the Bronze age with the giant limpets (Cymbula safiana and Patella ferruginea) being present since MIS6. To assess their distribution, predominance, and cultural significance this paper presents the results from an exhaustive archeozoological survey of the southern Iberian region. A total of 1628 specimens have been analysed, including 425 modern (333 C. safiana and 91 P. ferruginea) and 1203 from 60 archaeological deposits deriving from 36 sites, both coastal and continental. Giant limpets’ context also has been described and it has been related with a wide variety of deposits ranging from food refuse accumulations to occupations and burials.Detailed morphological and surface analysis allowed us to determine extraction methods and anthropic transformations. On coastal sites, the giant limpet record starts with Neanderthal populations from the Middle Palaeolithic and continues throughout the Upper Palaeolithic, Mesolithic, Neolithic, and Copper Age. On inland sites, giant limpets appear first in reduced numbers during the Late Neolithic and have been often worked into elliptical contours with polished, rib-free, external shell surfaces. In this study, we focus on the Copper Age, when giant limpet use becomes common, and records include tholoi, dolmens and other funerary contexts. The data indicate that the use of P. ferruginea is associated with Los Millares and El Argar cultures. Giant limpets use declines during the Bronze Age probably due to the major cultural shift that occurred during the Chalcolithic to Bronze transition.The data suggest that giant limpets should be considered as proxies of long-range trade during the Chalcolithic. We propose a new hypothesis linking giant limpets symbology with orbital/tidal variations and the ubiquitous use of marine elements as symbolism during this period.Our study highlights the relevance of shells in the reconstruction of the symbolic evolution of prehistoric cultures, as well as their connections with local ecosystem resources and regional commerce networks.