Biochronology and paleoclimatic implications of Middle Eocene to Oligocene planktic foraminiferal faunas

Planktic foraminiferal assemblages have been analyzed quantitatively in six DSDP sites in the Atlantic (Site 363), Pacific (Sites 292, 77B, 277), and Indian Ocean (Sites 219, 253) in order to determine the nature of the faunal turnover during Middle Eocene to Oligocene time. Biostratigraphic ranges of taxa and abundance distributions of dominant species are presented and illustrate striking similarities in faunal assemblages of low latitude regions in the Atlantic, Pacific and Indian oceans. A high resolution biochronology, based on dominant faunal characteristics and 55 datum events, permits correlation between all three oceans with a high degree of precision. Population studies provide a view of the global impact of the paleoclimatic and paleoceanographic changes occurring during Middle Eocene to Oligocene time.Planktic foraminiferal assemblage changes indicate a general cooling trend between Middle Eocene to Oligocene time, consistent with previously published oxygen isotope data. Major faunal changes, indicating cooling episodes, occur, however, at discrete intervals: in the Middle Eocene 44-43 Ma (P13), the Middle/Late Eocene boundary 41-40 Ma ( ), the Late Eocene 39-38 Ma ( ), the Eocene/Oligocene boundary 37-36 Ma (P18), and the Late Oligocene 31-29 Ma ( ). With the exception of the boundary, faunal changes occur abruptly during short stratigraphic intervals, and are characterized by major species extinctions and first appearances. The Eocene/Oligocene boundary cooling is marked primarily by increasing abundances of cool water species. This suggests that the boundary cooling, which marks a major event in the oxygen isotope record affected planktic faunas less than during other cooling episodes. Planktic foraminiferal faunas indicate that the boundary event is part of a continued cooling trend which began during the Middle Eocene.Two hiatus intervals are recognized in low and high latitude sections at the Middle/Late Eocene boundary and in the Late Eocene ( ). These hiatuses suggest that vigorous bottom water circulation began developing in the Middle Eocene, consistent with the onset of the faunal cooling trend, and well before the development of the psychrosphere at the boundary.     

The southernmost sirenian record in the eastern Pacific Ocean, from the Late Miocene of Chile

A tooth of a sirenian from the Late Miocene sediments of the Bahia Inglesa Formation (Chile) is described and referred to the Dugongidae. The fossil represents the first sirenian record from Chile and the southernmost record of the Sirenia in the eastern Pacific Ocean (latitude 27° S). The Chilean record extends the already wide geographical distribution of fossil sirenians along the Eastern Pacific coast. The presence of a sirenian during the Miocene on the Chilean coast is related to a globally warmer climatic condition and a still limited northern extension of the cold Humboldt Current. To cite this article: G. Bianucci, C. R. Palevol 5 (2006).     

Possible latitudinal clines in Antarctic intertidal and subtidal zone communities encrusting ephemeral hard substrata

Aim Encrusting faunal communities on rocks were examined from Southern Ocean intertidal and subtidal (6 m) zones to investigate potential change with latitude. Location The site locations were South Georgia (54°S [sub-Antarctic]), Signy Island (60.5°S [maritime Antarctic]) and Adelaide Island (68°S [high Antarctic]). Methods The number of taxa, degree of colonization and bryozoan growth and mortality were measured. Results The communities present were relatively simple in terms of composition and interactions. Spirorbid polychaetes (Annelida) and cheilostomatid bryozoans were the principal components. The community simplicity and dominance of unitary (compared to colonial) fauna increased with latitude. Mean annual mortality of subtidal cheilostomatids also significantly increased with latitude. The number of bryozoan species and potential aspects of community complexity increased with latitude. The growth of the bryozoan Inversiula nutrix increased with latitude reversing the general trend of decreased growth rate. Conclusions These findings suggest that disturbance may significantly increase with latitude within the Southern Ocean. The apparent reversal of typical latitudinal growth trends is probably a result of classical island biogeography, with species decreasing away from a centre of high diversity.     

基于GLBM模型的中国大陆阿根廷滑柔鱼鱿钓渔业CPUE标准化

西南大西洋阿根廷滑柔鱼既是西南大西洋生态系统中的重要种类,也是鱿钓渔业的重要捕捞对像.单位捕捞努力量渔获量(CPUE)是表示渔业资源状况及其丰度的常用指标.根据2000-2010年中国大陆鱿钓船在西南大西洋的生产统计数据和海洋卫星遥感获得的海洋环境数据(表温,表温水平梯度,海面高度,叶绿素浓度),利用基于贝叶斯的广义线性模型(GLBM),分未加入固定交互选项、加入固定交互选项和加入随机交互选项3种情况对中国大陆西南大西洋阿根廷滑柔鱼鱿钓渔业的CPUE进行标准化.根据偏差信息准则(DIC)值最小来确定最佳贝叶斯模型.结果表明,包含纬度、海表温度、表温水平梯度、海面高度、月×纬度、月×经度及年×纬度变量且加入随机交互项的GLBM模型为最适.标准化后的CPUE较名义CPUE小,年间变化平缓.与广义线性模型(GLM)和广义加性模型(GAM)标准化的CPUE比较,GLBM模型更能反映其资源丰度的真实水平.研究认为,2001-2010年间经GLBM模型标准化后的CPUE呈现逐年下降的趋势.     

Evaluating the efficacy of planktonic foraminifer calcite δO data for sea surface temperature reconstruction for the Late Miocene

This study examines the efficacy of published δ¹⁸O data from the calcite of Late Miocene surface dwelling planktonic foraminifer shells, for sea surface temperature estimates for the pre-Quaternary. The data are from 33 Late Miocene (Messinian) marine sites from a modern latitudinal gradient of 64°N to 48°S. They give estimates of SSTs in the tropics/subtropics (to 30°N and S) that are mostly cooler than present. Possible causes of this temperature discrepancy are ecological factors (e.g. calcification of shells at levels below the ocean mixed layer), taphonomic effects (e.g. diagenesis or dissolution), inaccurate estimation of Late Miocene seawater oxygen isotope composition, or a real Late Miocene cool climate. The scale of apparent cooling in the tropics suggests that the SST signal of the foraminifer calcite has been reset, at least in part, by early diagenetic calcite with higher δ¹⁸O, formed in the foraminifer shells in cool sea bottom pore waters, probably coupled with the effects of calcite formed below the mixed layer during the life of the foraminifera. This hypothesis is supported by the markedly cooler SST estimates from low latitudes—in some cases more than 9 °C cooler than present—where the gradients of temperature and the δ¹⁸O composition of seawater between sea surface and sea bottom are most marked, and where ocean surface stratification is high. At higher latitudes, particularly N and S of 30°, the temperature signal is still cooler, though maximum temperature estimates overlap with modern SSTs N and S of 40°. Comparison of SST estimates for the Late Miocene from alkenone unsaturation analysis from the eastern tropical Atlantic at Ocean Drilling Program (ODP) Site 958—which suggest a warmer sea surface by 2-4 °C, with estimates from oxygen isotopes at Deep Sea Drilling Project (DSDP) Site 366 and ODP Site 959, indicating cooler than present SSTs, also suggest a significant impact on the δ¹⁸O signal. Nevertheless, much of the original SST variation is clearly preserved in the primary calcite formed in the mixed layer, and records secular and temporal oceanographic changes at the sea surface, such as movement of the Antarctic Polar Front in the Southern Ocean. Cooler SSTs in the tropics and sub-tropics are also consistent with the Late Miocene latitude reduction in the coral reef belt and with interrupted reef growth on the Queensland Plateau of eastern Australia, though it is not possible to quantify absolute SSTs with the existing oxygen isotope data. Reconstruction of an accurate global SST dataset for Neogene time-slices from the existing published DSDP/ODP isotope data, for use in general circulation models, may require a detailed re-assessment of taphonomy at many sites.     

A geological history of the Turkana Basin

The Turkana Basin preserves a long and detailed record of biotic evolution, cultural development, and rift valley geology in its sedimentary strata. Before the formation of the modern basin, Cretaceous fluvial systems, Paleogene lakes, and Oligo-Miocene volcano-sedimentary sequences left fossil-bearing strata in the region. These deposits were in part related to an early system of rift basins that stretched from Sudan to the Indian Ocean. The present-day basin has its origins in Pliocene tectonic developments of the modern rift, with subsidence making room for more than one kilometer of Plio-Pleistocene strata. Much of this sequence belongs to the Omo Group, richly fossiliferous sediments associated with the ancestral Omo River and its tributaries. Modern Lake Turkana has a record stretching back more than 200 thousand years, with earlier lake phases throughout the Plio-Pleistocene. The geologic history of the basin is one of dynamic landscapes responding to environmental influences, including tectonics, volcanic activity and climate.     

Scoyenia Escape Burrows in Fluvial Pebbly Sand: Upper Triassic Sugarloaf Arkose,Deerfield Rift Basin,Massachusetts, USA

Late Triassic larvae of an insect, probably a beetle, moved diagonally upwards though fluvial pebbly sand along a thin mud layer, constructing Scoyenia burrows in the Sugarloaf Arkose, Deerfield rift basin, Massachusetts. They may have been escaping a temporary rise of the water table in the monsoonal dry season.     

Biogeographical and geological evidence for a smaller, completely-enclosed Pacific Basin in the Late Cretaceous

Aim To use biogeographical, palaeomagnetic, palaeosedimentary, and plate circuit data from Late Cretaceous regions in and around the Pacific to test the plate tectonic hypothesis of a pre‐Pacific superocean. Location East Asia, Australia, Antarctica, the western Americas, and the Pacific. Methods Literature surveys of the distributions of Cretaceous, circum‐Pacific taxa were compared with palaeomagnetic and palaeosedimentary data. Uncontroversial plate motions based on seafloor spreading data were also used to test the results of the biogeographical and palaeomagnetic analyses. Results The distributions of Cretaceous terrestrial taxa, mostly dinosaurs, imply direct, continental connections between Australia and East Asia, East Asia and North America, North America and South America, South America and Antarctica, and Antarctica and Australia. Palaeomagnetic, palaeosedimentary, and basic plate circuit analyses require little to no latitudinal motion of the Pacific plate with respect to the surrounding continents. Specifically, the data implies that western North America, East Asia, and the Pacific plate all increased in latitude by roughly the same amount (c. 11 ± 5°) since the Campanian – and that the Pacific Ocean Basin has increased in length north‐to‐south. Main conclusions Each of the analyses provides independent corroboration for the same conclusion: the Late Cretaceous Pacific plate was completely enclosed by the surrounding continents and has not experienced significant latitudinal motion with respect to North America, East Asia, or the Bering land bridge. This contrasts significantly with the plate tectonic history of the Pacific, implying instead that the Pacific plate formed in situ, pushing the continents apart as the plate and basin expanded. These results also substantiate recent biogeographical analyses that have concluded that a narrower Pacific Ocean Basin in the Mesozoic and early Tertiary provides the most reasonable explanation for the great number of trans‐Pacific disjunctions of poor dispersing taxa.     

Middle and Upper Triassic radiolarite components from the Kcira-Dushi-Komani ophiolitic mélange and their provenance (Mirdita Zone,Albania)

The Middle Jurassic Kcira-Dushi-Komani Mélange in the northwestern Mirdita Ophiolite Zone contains blocks of Triassic oceanic crust, radiolarites and open marine limestones. We describe the microfacies and present biostratigraphic data from radiolarite clasts and blocks and from basalt-radiolarite blocks with preserved autochthonous sedimentary cover. The radiolarians yield Middle to Late Triassic (Late Anisian to Late Norian) ages for the oceanic realm from which the ophiolite and radiolarite blocks and clasts derived. Together with limestone blocks, the provenance areas of the components in the Kcira-Dushi-Komani Mélange are determined as the distal shelf and the ocean floor of the Neotethys. In the course of ophiolite obduction, the components were transported by mass movements into newly formed trench-like basins in front of the westward propagating nappe stack. These basins were later incorporated in the nappe stack forming the typical features of a syntectonic mélange. Our radiolarian biostratigraphic data confirm Late Anisian formation of the Neotethys Ocean, parts of which became closed in the Middle Jurassic. The data clearly speak in favour of one Neotethys Ocean to the east, from which the Mirdita ophiolites derived as far-travelled nappes.     

Kerguelen Plateau and the Late Cretaceous southern-continent bioconnection hypothesis: tales from a topographical ocean

Aim  To evaluate rigorously an influential palaeobiogeographical hypothesis which states that in the Late Cretaceous (until c. 80 Ma) the Kerguelen Plateau provided a terrestrial causeway between East Antarctica and India that, in turn, formed part of a longer overland route between South America and Madagascar.
Location  Southern Ocean, Indian Ocean, East Antarctica, India and Madagascar.
Methods  Palaeogeographical modelling drawing on geological and geophysical data, bathymetric charts and plate tectonic reconstructions.
Results  During the Late Cretaceous, only small portions of the present-day Kerguelen Plateau were sub-aerial. Additionally, the plateau's north-north-west and south-south-east ends did not directly abut India and Antarctica, but instead were separated by large gaps. Thus, the notion that the two continents were then linked by a land route running the entire length of the edifice is almost certainly incorrect.
Main conclusions  The currently available physical evidence indicates that the Late Cretaceous southern-continent connection hypothesis, which is based exclusively on biological data, is untenable. Assuming the fossil and/or extant biological records of Madagascar–India are closely related to those of South America, alternative palaeogeographical scenarios need to be explored to explain this conundrum. Overwater dispersal and/or an alternative passage involving a more direct route via Africa (with crossings of the Mozambique Channel and a then appreciably narrower Central Atlantic) should be considered.     

The case for creation of the North Pacific Ocean during the Mesozoic Era

Pangean reconstructions based on the Dymaxion Projection are discussed, and the advantages of placing cordilleran North America alongside eastern Asia are clearly seen. A detailed matching of the western North American and eastern Asian continental margins shows that the North Pacific can be closed as tightly as the Atlantic when appropriate adjustments are made to reproduce Permian geography. Closure of the North Pacific eliminates overlap of cordilleran North America with South America in the Caribbean region and permits closure of the Arctic Ocean.Geological and paleontological data are presented which permit a tentative Phanerozoic history of the North Pacific to be outlined. According to this view, cordilleran North America and the North China craton were rifted from cratonic North America at the dawn of the Phanerozoic. They drifted westward across a proto-Pacific Ocean and were temporarily sutured to the Siberian craton along the Sayanian fold belt during the world-wide Early Paleozoic orogenies. Final suture occurred along the Mongolian fold belt during the world-wide Late Paleozoic orogenies which completed the consolidation of Pangea. Separation of cordilleran North America from eastern Asia was part of the Mesozoic fragmentation of Pangea. Mesozoic sea-floor spreading carried cordilleran North America eastward and opened the present North Pacific. Cordilleran North America was sutured to cratonic North America during the world-wide Cenozoic orogenies. Suture began along the Nevadan-Sevier fold belt and was followed by under-riding along the Laramide fold belt. North America then partly over-rode the East Pacific Rise sea-floor spreading center, and dextral transform faults across the rift valley created faults and oroclines in cordilleran North America.A driving force for the disintegration of Pangea is provided by the unstable tetrahedral convection model. This model is fitted to Phanerozoic world maps for all periods beginning with the Permian to show how an opening North Pacific Ocean can be made compatible with opening of the Atlantic, Indian, and Arctic Oceans. The unstable tetrahedral convection model also provides a mechanism for opening the Cenozoic small ocean basins behind West Pacific island arcs. Such basins form above abandoned convection plumes or curtains which rise passively to the earth's surface. These plumes and curtains are abandoned when the potential energy-driving convection is locally exhausted.     

An Oplegnathid beak (Osteichthyes: Perciformes) from the Early Miocene of Patagonia. Extirpation of several vertebrates from the southern Atlantic Ocean

The first record of the knifejaw family Oplegnathidae in the Atlantic Ocean and in South America is reported. It comes from the lowermost beds of the Early Miocene Gaiman Formation at the lower Río Chubut valley, central-eastern Patagonia. The family Oplegnathidae does not occur in the Atlantic today, but it was widespread in comparison to other knifejaw fishes, such as scarids and odacids. Several aquatic vertebrates were extirpated from the southern Atlantic Ocean in the Late Neogene. This record establishes a minimal age (Early Miocene) for the extirpation of the family Oplegnathidae in the Atlantic Ocean.     

Longitude perception and bicoordinate magnetic maps in sea turtles

Long-distance animal migrants often navigate in ways that imply an awareness of both latitude and longitude. Although several species are known to use magnetic cues as a surrogate for latitude, it is not known how any animal perceives longitude. Magnetic parameters appear to be unpromising as longitudinal markers because they typically vary more in a north-south rather than an east-west direction. Here we report, however, that hatchling loggerhead sea turtles (Caretta caretta) from Florida, USA, when exposed to magnetic fields that exist at two locations with the same latitude but on opposite sides of the Atlantic Ocean, responded by swimming in different directions that would, in each case, help them advance along their circular migratory route. The results demonstrate for the first time that longitude can be encoded into the magnetic positioning system of a migratory animal. Because turtles also assess north-south position magnetically, the findings imply that loggerheads have a navigational system that exploits the Earth's magnetic field as a kind of bicoordinate magnetic map from which both longitudinal and latitudinal information can be extracted.     

Patterns and controlling factors of species diversity in the Arctic Ocean

Aim The Arctic Ocean is one of the last near‐pristine regions on Earth, and, although human activities are expected to impact on Arctic ecosystems, we know very little about baseline patterns of Arctic Ocean biodiversity. This paper aims to describe Arctic Ocean‐wide patterns of benthic biodiversity and to explore factors related to the large‐scale species diversity patterns. Location Arctic Ocean. Methods We used large ostracode and foraminiferal datasets to describe the biodiversity patterns and applied comprehensive ecological modelling to test the degree to which these patterns are potentially governed by environmental factors, such as temperature, productivity, seasonality, ice cover and others. To test environmental control of the observed diversity patterns, subsets of samples for which all environmental parameters were available were analysed with multiple regression and model averaging. Results Well‐known negative latitudinal species diversity gradients (LSDGs) were found in metazoan Ostracoda, but the LSDGs were unimodal with an intermediate maximum with respect to latitude in protozoan foraminifera. Depth species diversity gradients were unimodal, with peaks in diversity shallower than those in other oceans. Our modelling results showed that several factors are significant predictors of diversity, but the significant predictors were different among shallow marine ostracodes, deep‐sea ostracodes and deep‐sea foraminifera. Main conclusions On the basis of these Arctic Ocean‐wide comprehensive datasets, we document large‐scale diversity patterns with respect to latitude and depth. Our modelling results suggest that the underlying mechanisms causing these species diversity patterns are unexpectedly complex. The environmental parameters of temperature, surface productivity, seasonality of productivity, salinity and ice cover can all play a role in shaping large‐scale diversity patterns, but their relative importance may depend on the ecological preferences of taxa and the oceanographic context of regions. These results suggest that a multiplicity of variables appear to be related to community structure in this system.     

High northern palaeolatitude Jurassic-Cretaceous palaeotemperature variation: new data from Kong Karls Land, Svalbard

The traditional view of warm equable global climates in the Mesozoic with weakly developed latitudinal temperature gradients has been challenged by several recent studies. However, reliable high palaeolatitude palaeotemperature data is still rare. In this study palaeotemperature data, based on oxygen stable isotope palaeothermometry of well preserved mid Jurassic to Lower Cretaceous belemnites from Kong Karls Land, Svalbard, are presented. These data show cool high latitude marine isotopic palaeotemperatures for endemic species during the Lower to mid Valanginian (7.7°C), which may be compatible with the formation of high latitude ice. Middle Bathonian to Kimmeridgian samples give warmer isotopic palaeotemperatures (9.4°C), whilst samples from the Aalenian to Bajocian give isotopic palaeotemperatures which are warmer still (12.7°C). Comparison of the Callovian temperatures with those from a mid-latitude location shows them to be warmer than would be expected if previous latitudinal temperature gradients are correct. This may be due to the ameliorating effect of oceanic heat transport pole-wards from the Panthalassa Ocean via the South Anyui Ocean.     

Vertical distribution of heterotrophic bacteria in the western half of the Indian ocean]

The peculatities of quantitative distribution of heterotrophic bacteria at various depths in the water colum of the western part of the Indian Ocean between 23 degrees N and 44 degrees S latitude were studied. A scheme of the hydrological sturcture of the Indian Ocean was constructed on the basis of microbiological data. In general features, this scheme has much in common with that which was depicted for the eastern part of this ocean in 1956--1957.     

Assimilation de composés organiques dissous dans le secteur antarctique de l'Ocean Indien.

Uptake of Dissolved Organic Compounds in the Antarctic Sector of the Indian Ocean The kinetic approach was used to determine the heterotrophic potential of the Indian Antarctic waters for three dissolved organic compouds: glucose, proline and glutamate. Variations with depth and latitude are discussed.     

Middle Eocene–Early Pliocene Subantarctic planktic foraminiferal biostratigraphy of Site 1090, Agulhas Ridge

The analysis of planktic foraminiferal assemblages from Site 1090 (ODP Leg 177), located in the central part of the Subantarctic Zone south of South Africa, provided a geochronology of a 330-m-thick sequence spanning the Middle Eocene to Early Pliocene. A sequence of discrete bioevents enables the calibration of the Antarctic Paleogene (AP) Zonation with lower latitude biozonal schemes for the Middle–Late Eocene interval. In spite of the poor recovery of planktic foraminiferal assemblages, a correlation with the lower latitude standard planktic foraminiferal zonations has been attempted for the whole surveyed interval. Identified bioevents have been tentatively calibrated to the geomagnetic polarity time scale following the biochronology of Berggren et al. (1995). Besides planktic foraminiferal bioevents, the disappearance of the benthic foraminifera Nuttallides truempyi has been used to approximate the Middle/Late Eocene boundary. A hiatus of at least 11.7 Myr occurs between 78 and 71 m composite depth extending from the Early Miocene to the latest Miocene–Early Pliocene. Middle Eocene assemblages exhibit a temperate affinity, while the loss of several planktic foraminiferal species by late Middle to early Late Eocene time reflects cooling. During the Late Eocene–Oligocene intense dissolution caused impoverishment of planktic foraminiferal assemblages possibly following the emplacement of cold, corrosive bottom waters. Two warming peaks are, however, observed: the late Middle Eocene is marked by the invasion of the warmer water Acarinina spinuloinflata and Hantkenina alabamensis at 40.5 Ma, while the middle Late Eocene experienced the immigration of some globigerinathekids including Globigerinatheka luterbacheri and Globigerinatheka cf. semiinvoluta at 34.3 Ma. A more continuous record is observed for the Early Miocene and the Late Miocene–Early Pliocene where planktic foraminiferal assemblages show a distinct affinity with southern mid- to high-latitude faunas.     

Paleoceanographic changes during the past 1.9 Myr at DSDP Site 238, Central Indian Ocean Basin: Benthic foraminiferal proxies

Deep-sea benthic foraminifera have been quantitatively analyzed in samples (> 125 μm size fraction) from Ocean Drilling Program (ODP) Site 238, to understand paleoceanographic changes in the Central Indian Basin over the past 1.9 Myr. Factor and cluster analyses of the 25 highest-ranked species made it possible to identify five biofacies, characterizing distinct deep-sea environmental settings. The environmental interpretation of each biofacies is based on the ecology of recent deep-sea benthic foraminifera. The benthic faunal record indicates fluctuating deep-sea conditions in environmental parameters including oxygenation, surface productivity and organic food supply. These changes appear to be linked to Indian summer monsoon variability, the main climatic feature of the Indian Ocean region. The benthic assemblages show a major shift at ∼ 0.7 to 0.6 Ma, marked by major turnovers in the relative abundances of species, coinciding with an increased amplitude of glacial cycles. These cycles appear to have influenced low latitude monsoonal climate as well as deep-sea conditions in the Central Indian Ocean Basin.     

Back to the future? Late Holocene marine food web structure in a warm climatic phase as a predictor of trophodynamics in a warmer South‐Western Atlantic Ocean

Stable carbon and nitrogen isotope ratios in the skeletal elements of both ancient and modern marine species from the Beagle Channel were used to compare the structure of Late Holocene and modern food webs, and predict potential changes as a result of a Sea Surface Temperature (SST) increase in the region. Complementary, ancient and modern shells of limpets and mussels were isotopically analysed to explore changes in the isotopic baseline and compare marine food webs through time after an appropriate correction for baseline shifts. Results confirmed a declining pattern of marine primary productivity during the Late Holocene in the Beagle Channel. In general, the isotopic niches overlapped largely in the ancient food web in comparison to the current marine one, with the exception of that of cormorants (Phalacrocorax sp.). Our data suggest that all the species that have undergone intense human exploitation (Arctocephalus australis, Otaria flavescens and Merluccius sp.) significantly increased their trophic levels. The most important finding of this work was the very high isotopic overlap between snoek (Thyrsites atun) and hake (Merluccius sp.) during the Late Holocene. Increasing SST as a result of global warming could favour the recolonization of the southern South‐Western Atlantic Ocean by snoek from the South‐Eastern Pacific Ocean, with a potential impact on the landings of the economically important Argentine and Austral hake. These findings highlight the relevance of using zooarchaeological remains for providing predictions about marine food webs changes in the near future.