Temperate Fauna Research Articles

Squirrels (Rodentia, Sciuridae) of the Early Miocene Tagay fauna in Eastern Siberia

The Tagay vertebrate fauna (Olkhon Island, Lake Baikal, Russia) dated to the late Early Miocene yielded a diverse association of sciurine rodents, including flying squirrel Hylopetes sp., tree squirrels Sciurus cf. lii, Sciurus sp., and Blackia cf. miocaenica, and a numerically dominant small marmotine Miospermophilus debruijni. The presence of flying and tree squirrels indicates the presence of wooded biotopes. The record of Blackia is remarkably distant (more than 4000 km) from the nearest synchronous records in western Asia (Anatolia) and Eastern Europe thus implying a continuous distribution range of this genus stretching through the middle latitudes of the Holarctic and likely marking the continental belt of temperate forests in late Early Miocene. Marmotines of North American origin document direct faunal communication between temperate faunas of the Old and New Worlds at that time.

Active microeukaryotes hold clues of effects of global warming on benthic diversity and connectivity in the coastal sediments

The marine flora and fauna along the China seas include the Indo-West Pacific warm-water fauna and the North Pacific temperate fauna. The latitude of 32°N is recognized as the ecological barrier for benthic fauna in the China Seas. However, the ecological barrier on macrobenthos community gradually weakened because of global warming. Microeukaryotes are major components of marine food webs and can quickly response to environmental changes. We hypothesis that microeukaryotic benthos can stride over the ecological barrier of 32°N from the East China Sea (ECS) to the Yellow Sea (YS) under the global change, but their distribution is still limited by depth gradients between the South China Sea (SCS) and the ESC. Therefore, we investigated the distribution of benthic microeukaryotes in the China Seas using RNA metabarcoding. Higher OTU richness and phylogenetic diversity were detected in the SCS than those in the YS and ECS. The YS and ECS communities clustered together firstly and then clustered with the SCS community. Unexpectedly, communities from the 33°N in the YS clustered with those from the ECS. Similar pattern was also detected for Cercozoa, Diatomea, Amoebozoa and Fungi. These findings indicated that microeukaryotic benthos strode over the ecological barrier of 32°N under the global change. Source-sink analyses indicated more than 50% sources of the 33°N community were attributed to the ECS community, while only 12.5% from the YS community. Depth, temperature and latitude showed significant influence on communities in the China Seas. This study highlights the response of active microeukaryotes to the global warming in the coastal sediments.

Historical biogeography supports Point Conception as the site of turnover between temperate East Pacific ichthyofaunas.

The cold temperate and subtropical marine faunas of the Northeastern Pacific meet within California as part of one of the few eastern boundary upwelling ecosystems in the world. Traditionally, it is believed that Point Conception is the precise site of turnover between these two faunas due to sharp changes in oceanographic conditions. However, evidence from intraspecific phylogeography and species range terminals do not support this view, finding stronger biogeographic breaks elsewhere along the coast. Here I develop a new application of historical biogeographic approaches to uncover sites of transition between faunas without needing an a priori hypothesis of where these occur. I used this approach to determine whether the point of transition between northern and southern temperate faunas occurs at Point Conception or elsewhere within California. I also examined expert-vetted latitudinal range data of California fish species from the 1970s and the 2020s to assess how biogeography could change with the backdrop of climate change. The site of turnover was found to occur near Point Conception, in concordance with the traditional view. I suggest that recent species- and population-level processes could be expected to give signals of different events from historical biogeography, possibly explaining the discrepancy across studies. Species richness of California has increased since the 1970s, mostly due to species's ranges expanding northward from Baja California (Mexico). Range shifts under warming conditions seem to be increasing the disparity between northern and southern faunas of California, creating a more divergent biogeography.

Unveiling a hotspot of genetic diversity in southern Italy for the endangered Hermann’s tortoise Testudo hermanni

BackgroundHotspots of intraspecific genetic diversity represent invaluable resources for species to cope with environmental changes, and their identification is increasingly recognized as a major goal of conservation ecology research. However, even for iconic and endangered species, conservation strategies are often planned without thorough information on the geographic patterns of genetic variation. Here, we investigated the spatial patterns of genetic variation of the endangered Hermann’s tortoise Testudo hermanni in the Italian Peninsula by genotyping 174 individuals at 7 microsatellite loci, with the aim to contribute to planning effective conservation strategies.ResultsOrdination-based and Bayesian clustering analyses consistently identified three main genetic clusters, one spread in the central and northern part of the peninsula, and two restricted to southern Italy and Sicily, respectively. The highest levels of genetic diversity were found in populations of the southern cluster and, in particular, at the northern edges of its distribution (He > 0.6, Ar > 2.8 ), that correspond to areas of putative secondary contact and admixture between distinct lineages. Our results clearly identify a hotspot of genetic diversity for the Hermann’s tortoise in southern Italy.ConclusionWe inferred the evolutionary history and the spatial patterns of genetic variation of the Hermann’s tortoise in the Italian Peninsula. We identified three main genetic clusters along the peninsula and a hotspot of intraspecific diversity in southern Italy. Our results underline the urgent need for conservation actions to warrant the long-term persistence of viable tortoise populations in this area. Furthrmore, these data add further evidence to the role of southern Italy as a biodiversity hotspot for temperate fauna, claiming for higher consideration of this area in large scale conservation programs.

Global decline of pelagic fauna in a warmer ocean

Pelagic fauna is expected to be impacted under climate change according to ecosystem simulations. However, the direction and magnitude of the impact is still uncertain and still not corroborated by observation-based statistical studies. Here we compile a global underwater sonar database and 20 ocean climate projections to predict the future distribution of sound-scattering fauna around the world’s oceans. We show that global pelagic fauna will be seriously compromised by the end of the twenty-first century if we continue under the current greenhouse emission scenario. Low and mid latitudes are expected to lose from 3% to 22% of animal biomass due to the expansion of low-productive systems, while higher latitudes would be populated by present-day temperate fauna, supporting results from ecosystem simulations. We further show that strong mitigation measures to contain global warming below 2 °C would reduce these impacts to less than half. The authors compile an underwater sonar database to understand the current and future distribution of pelagic fauna in the world’s oceans. They show loss of 3–22% of these fauna in low and mid latitudes under high-emissions scenarios, with impact reduced to less than half if global warming is contained below 2 °C.

Comparative population genetics of the federally endangered Relict Darter, and its sister taxon the Clarks Darter (Teleostei: Percidae)

The southeastern United States harbors one of the most diverse temperate freshwater fish faunas of the world. Unfortunately, due to improper land use practices and habitat degradation, many of the species in this region are imperiled and may become extinct without appropriate conservation efforts. This study examined the population dynamics of an endangered endemic darter of southwest Kentucky, the Relict Darter (Etheostoma chienense) and its sister taxon, the undescribed Clarks Darter (Etheostoma cf. oophylax). Mitochondrial sequence data coupled with SNP data were used to infer population structure, gene flow, genetic variation, and effective population sizes of both species. The results from this study, based on 160 individuals from nine localities, indicate that the endangered Relict Darter possesses limited genetic variation based on mitochondrial DNA haplotypes (N = 4). In addition, SNP data (6.8 k markers) further indicates limited genetic structure (K = 1), as well as a low effective population size (143–918), suggesting that the Relict Darter can be managed as a single, panmictic conservation unit. It is suggested that conservation efforts be taken to protect remaining habitats, augment the system with artificial spawning substrates, and, as a last resort (if needed), supplement the natural population with captive reared individuals. Ethesotoma cf. oophylax showed some genetic variation among distant sites, but more samples are needed throughout the range in order to fully understand the population dynamics of this species.

Revision of the occurrence of muskox (Ovibos moschatus Zimmermann 1780) from the Gravettian of Arbreda Cave (Serinyà, northeastern Iberian Peninsula): new insights for the study of Iberian cold‐adapted faunas

During the Last Glacial cycle (MIS 4 to MIS 2), the isthmic Pyrenees mountain range acted as a biogeographical barrier, effectively restricting faunal exchanges to its western and eastern terminations. The study of the composition of megaherbivore communities has revealed the transitional character of the Cantabrian region (northwest Iberian Peninsula) during the MIS 3, between western European cold faunas and southern Iberian temperate faunas. In the Catalan area (northeastern Iberian Peninsula), cold‐adapted faunas are frequently recorded during the cold pulses of MIS 3 and MIS 2, albeit to a lesser extent. In the present paper, we provide the first direct evidence of a muskox record in the Iberian Peninsula, together with a morphometric study and the results of collagen δ13C and δ15N analysis. The results reveal that the Arbreda specimen fits biometrically within the Late Holocene Umingmak specimens (Banks Island, Canada). Moreover, its isotopic values fall into the range of Late Pleistocene Mammoth steppe muskoxen, which indicates a typical ecological behaviour for muskox. Indeed, it suggests a niche partitioning of this cold‐adapted specimen in relation to other Gravettian Iberian fauna. Chronologically, this occurrence is interpreted as an isolated southward expansion of the biogeographical limits of muskox during the Greenland Stadial 4, in the latest MIS 3.

Two new species of deep-water Calcigorgia gorgonians (Anthozoa: Octocorallia) from the Kurile Islands, Sea of Okhotsk, with a review of distinctive characters of the known species of the genus

This paper provides descriptions of Calcigorgia gorgonians collected from the Sea of Okhotsk and shores of the Kurile Islands between 3 Aug. 1984 and 20 Aug. 1987. New species described are the deep-water gorgonians Calcigorgia matua sp. nov. and C. simushiri sp. nov., belonging to the temperate fauna of the North Pacific hemisphere. Specimens belonging to all species of the genus were examined and the distinctive characters for each one are provided and summarized in a table. A modified diagnosis of the genus is proposed. The finding of a previously undescribed species emphasizes the need of further surveys, particularly in shelf and deeper waters, in order to improve our knowledge of this neglected fauna in Far East seas.

Olson's Extinction and the latitudinal biodiversity gradient of tetrapods in the Permian.

The terrestrial vertebrate fauna underwent a substantial change in composition between the lower and middle Permian. The lower Permian fauna was characterized by diverse and abundant amphibians and pelycosaurian-grade synapsids. During the middle Permian, a therapsid-dominated fauna, containing a diverse array of parareptiles and a considerably reduced richness of amphibians, replaced this. However, it is debated whether the transition is a genuine event, accompanied by a mass extinction, or whether it is merely an artefact of the shift in sampling from the palaeoequatorial latitudes to the palaeotemperate latitudes. Here we use an up-to-date biostratigraphy and incorporate recent discoveries to thoroughly review the Permian tetrapod fossil record. We suggest that the faunal transition represents a genuine event; the lower Permian temperate faunas are more similar to lower Permian equatorial faunas than middle Permian temperate faunas. The transition was not consistent across latitudes; the turnover occurred more rapidly in Russia, but was delayed in North America. The argument that the mass extinction is an artefact of a latitudinal biodiversity gradient and a shift in sampling localities is rejected: sampling correction demonstrates an inverse latitudinal biodiversity gradient was prevalent during the Permian, with peak diversity in the temperate latitudes.

Phylogeography of the Subgenus Drosophila (Diptera: Drosophilidae): Evolutionary History of Faunal Divergence between the Old and the New Worlds

The current subgenus Drosophila (the traditional immigrans-tripunctata radiation) includes major elements of temperate drosophilid faunas in the northern hemisphere. Despite previous molecular phylogenetic analyses, the phylogeny of the subgenus Drosophila has not fully been resolved: the resulting trees have more or less varied in topology. One possible factor for such ambiguous results is taxon-sampling that has been biased towards New World species in previous studies. In this study, taxon sampling was balanced between Old and New World species, and phylogenetic relationships among 45 ingroup species selected from ten core species groups of the subgenus Drosophila were analyzed using nucleotide sequences of three nuclear and two mitochondrial genes. Based on the resulting phylogenetic tree, ancestral distributions and divergence times were estimated for each clade to test Throckmorton’s hypothesis that there was a primary, early-Oligocene disjunction of tropical faunas and a subsequent mid-Miocene disjunction of temperate faunas between the Old and the New Worlds that occurred in parallel in separate lineages of the Drosophilidae. Our results substantially support Throckmorton’s hypothesis of ancestral migrations via the Bering Land Bridge mainly from the Old to the New World, and subsequent vicariant divergence of descendants between the two Worlds occurred in parallel among different lineages of the subgenus Drosophila. However, our results also indicate that these events took place multiple times over a wider time range than Throckmorton proposed, from the late Oligocene to the Pliocene.

Before the freeze: otoliths from the Eocene of Seymour Island, Antarctica, reveal dominance of gadiform fishes (Teleostei)

The first record of fossil teleostean otoliths from Antarctica is reported. The fossils were obtained from late Early Eocene shell beds of the La Meseta Formation, Seymour Island that represent the last temperate marine climate phase in Antarctica prior to the onset of cooling and subsequent glaciation during the late Eocene. A total of 17 otolith-based teleost taxa are recognized, with 10 being identifiable to species level containing nine new species and one new genus: Argentina antarctica sp. nov., Diaphus? marambionis sp. nov., Macruronus eastmani sp. nov., Coelorinchus balushkini sp. nov., Coelorinchus nordenskjoeldi sp. nov., Palimphemus seymourensis sp. nov., Hoplobrotula? antipoda sp. nov., Notoberyx cionei gen. et sp. nov. and Cepola anderssoni sp. nov. Macruronus eastmani sp. nov. is also known from the late Eocene of Southern Australia, and Tripterophycis immutatus Schwarzhans, widespread in the southern oceans during the Eocene, has been recorded from New Zealand, southern Australia, and now Antarctica. The otolith assemblage shows a typical composition of temperate fishes dominated by gadiforms, very similar at genus and family levels to associations known from middle Eocene strata of New Zealand and the late Eocene of southern Australia, but also to the temperate Northern Hemisphere associations from the Paleocene of Denmark. The Seymour Island fauna bridges a gap in the record of global temperate marine teleost faunas during the early Eocene climate maximum. The dominant gadiforms are interpreted as the main temperate faunal component, as in the Paleocene of Denmark. Here they are represented by the families Moridae, Merlucciidae (Macruroninae), Macrouridae and Gadidae. Nowadays Gadidae are a chiefly Northern Hemisphere temperate family. Moridae, Macruroninae and Macrouridae live today on the lower shelf to deep-water or mesopelagically with Macruroninae being restricted to the Southern Ocean. The extant endemic Antarctic gadiform family Muraenolepididae is missing, as are the dominant modern Antarctic fishes of the perciform suborder Notothenioidei. Recently, there has been much debate on isolated jaw bones of teleost fishes found in the La Meseta Formation and whether they would represent gadiforms (Merlucciidae in this case) or some early, primitive notothenioid. Otoliths are known to often complement rather than duplicate skeletal finds. With this in mind, we conclude that our otolith data support the presence of gadiforms in the early Eocene of Antarctica while it does not rule out the presence of notothenioids at the same time.http://zoobank.org/urn:lsid:zoobank.org:pub:A30E5364-0003-4467-B902-43A41AD456CC

Latitudinal gradients and indicator species in ungulate paleoassemblages during the MIS 3 in W Europe

Studies of mammal assemblages for the European MIS 3 have focused on a regionalization using presence–absence data and traditional cluster analysis. Although this approach has revealed mammal assemblages with no modern analogs, it can easily miss two important dynamical aspects of the MIS 3 assemblages, namely, transitional regions and faunal mixtures. We revisited this regionalization using a complementary approach based on the study of quantitative data for ungulate species. The main aim of this work is to evaluate whether the MIS 3 climatic oscillations led to a mixture of faunas or a latitudinal gradient in faunal composition, as well as to identify indicator species for different areas in ungulate mammal paleoassemblages of Western Europe.Ungulate faunal compositions of 86 fossil assemblages from 63 Western European sites of MIS 3 age were gathered from published sources. The distribution area was divided into four regions: central W Europe, S France, Cantabrian region and rest of the Iberian Peninsula. Chronologies of the assemblages were collected and calibrated. Multivariate ordination and indicator value analysis were carried out.Our study provided four main results: (i) there was a latitudinal faunal turnover during the MIS 3 period consistent with a temperature gradient; (ii) the Cantabrian region hosted a transitional faunal assemblage between the northern cold faunas and the southern temperate faunas; (iii) it was possible to find indicator species of large herbivores for different geographical areas along that latitudinal gradient, although not all of them were linked to climate but to orography (mainly in Cantabrian and other Iberian sites); and (iv) within those indicator species, a signal of mixed temperate and cold faunas was discernible. Together, this evidence supports a scenario in which the succession of cold and warm episodes typical from MIS 3 left signals of mixed cold and temperate faunal assemblages but without totally blurring the latitudinal gradient in climatic conditions.

The cushion–star Parvulastra exigua in South Africa: one species or more?

The cushion–star Parvulastra exigua (Lamarck, 1816) is a widely distributed member of the temperate intertidal fauna in the southern hemisphere. In South Africa, it occurs in sympatry with the endemic Parvulastra dyscrita (Clark, 1923), the two species being differentiated predominantly by gonopore placement. Several recent studies have suggested that there may be additional cryptic species within the Parvulastra exigua complex in South Africa, based variously on color morphology, genetic evidence and the differential placement of the gonopores. This paper attempts to resolve whether one or more species are represented within Parvulastra exigua. A total of 346 Parvulastra exigua and 8 Parvulastra dyscrita were collected from sites on the west and south–west coasts of South Africa; morphological, anatomical and genetic analyses were performed to determine whether cryptic species and/or Parvulastra exigua specimens with aboral gonopores were present. Results show that neither cryptic species nor Parvulastra exigua specimens with aboral gonopores occur at these sites. This study thus refutes previous claims of the existence of aboral gonopores in South African Parvulastra exigua, and suggests that a single species is represented. The distinction between Parvulastra exigua and Parvulastra dyscrita is also confirmed, and features separating these two species are clarified and documented.

Terrestrial and Aquatic Mollusks of the Eocene Kishenehn Formation, Middle Fork Flathead River, Montana

The Kishenehn Formation of northwest Montana and southeast British Columbia hosts one of the most prolific and diverse assemblages of fossil nonmarine mollusks in North America. More than 76 taxa, of which 41 are newly described species, of middle Eocene to early Miocene terrestrial and aquatic gastropods have been collected and described. This paper reports on the discoveries made in the oldest part of the formation that is middle Eocene in age in the southernmost part of the Kishenehn Basin. Outcrops along the Middle Fork of the Flathead River from this area have yielded over 1400 specimens from which 62 taxa (37 terrestrial, 25 aquatic) were identified. Of these, eight are new species and nine were described elsewhere but were not previously reported in the formation. In terms of paleoenvironmental affinities, the fauna are divisible into three groups. Group I is a relict tropical wet fauna, existing in basinal waterways whose modern analogs live in the Caribbean and Central and South America. Group II is a subtropical, semi-arid fauna with modern analogs ranging from the north coast of the Gulf of Mexico, across the southern United States and northern Mexico to southern California and the Baja Peninsula. Group III is a humid, warm temperate fauna that was transported from mountains east of the basin and deposited in fan-delta and lake-margin settings. Modern analogs of these molluscan taxa are common in the east-central United States. The unusual coexistence of these climatically disparate groups of fossil mollusks is a manifestation of the large paleotopographic relief, perhaps greater than 2000 m, that existed between the valley floor and the mountains. The following taxa are described herein by the senior author (HGP) as new species: Bivalvia: Sphaeriidae- Sphaerium lentum, Pisidium triangulatum. Gastropoda: Proserpinellidae- Tozerpina elsae; Subulinidae- Obeliscus scalplockensis; Planorbidae- Ferrissia circus, Rhodacmaea crepida, Omalodiscus spira; Physidae- Physella olive; and one new subspecies: Gastropoda: Pupillidae- Pupilla hebes sinistra.

Unique mitochondrial DNA lineages in Irish stickleback populations: cryptic refugium or rapid recolonization?

Repeated recolonization of freshwater environments following Pleistocene glaciations has played a major role in the evolution and adaptation of anadromous taxa. Located at the western fringe of Europe, Ireland and Britain were likely recolonized rapidly by anadromous fishes from the North Atlantic following the last glacial maximum (LGM). While the presence of unique mitochondrial haplotypes in Ireland suggests that a cryptic northern refugium may have played a role in recolonization, no explicit test of this hypothesis has been conducted. The three-spined stickleback is native and ubiquitous to aquatic ecosystems throughout Ireland, making it an excellent model species with which to examine the biogeographical history of anadromous fishes in the region. We used mitochondrial and microsatellite markers to examine the presence of divergent evolutionary lineages and to assess broad-scale patterns of geographical clustering among postglacially isolated populations. Our results confirm that Ireland is a region of secondary contact for divergent mitochondrial lineages and that endemic haplotypes occur in populations in Central and Southern Ireland. To test whether a putative Irish lineage arose from a cryptic Irish refugium, we used approximate Bayesian computation (ABC). However, we found no support for this hypothesis. Instead, the Irish lineage likely diverged from the European lineage as a result of postglacial isolation of freshwater populations by rising sea levels. These findings emphasize the need to rigorously test biogeographical hypothesis and contribute further evidence that postglacial processes may have shaped genetic diversity in temperate fauna.

Rates of warming and the global sensitivity of shallow water marine invertebrates to elevated temperature

Assessing the sensitivity of ectotherms to variability in their environment is a key challenge, especially in the face of rapid warming of the Earth's surface. Comparing the upper temperature limits of species from different regions, at different rates of warming, has recently been developed as a method to estimate the long term sensitivity of shallow marine fauna. This paper presents the first preliminary data from four tropical Ascension Island, five temperate New Zealand and six Antarctic McMurdo Sound species. The slopes and intercepts of these three assemblages fitted within the overall pattern for previously measured assemblages from high temperature tolerance in tropical fauna and a shallow slope, to low temperature tolerance and a steep slope in Antarctic fauna. Despite the tropical oceanic Ascension Island being subject to upwelling events, the fit of the intercept and slope within the overall assemblage pattern suggests that the upwelling is sufficiently predictable for the fauna to have evolved the plasticity to respond. This contrasts with previously analysed species from the Peruvian upwelling region, which had a steeper slope than other temperate fauna. The speed and capacity of faunal assemblages to acclimatize their physiology is likely to determine the shape of the rates of warming relationship, and will be a key mechanism underpinning vulnerability to climate warming.

Global diversity and endemism in Early Silurian (Aeronian) brachiopods

Silurian brachiopods of Middle Llandovery (Aeronian) ages are reviewed, and 215 genera are identified here, compared with 109 in the preceding Early Llandovery (Rhuddanian), indicating a recovery-radiation interval after the end-Ordovician mass extinction. The chief regions in which they are found are the continents of South China, Avalonia-Baltica, Laurentia and Siberia, which were all at tropical latitudes with the exception of Avalonia. In addition, the very large superterrane of Gondwana, although with patchy brachiopod distribution, included temperate faunas, as well as subtropical faunas (in Iran and Afghanistan). Aeronian brachiopods greatly increased in diversity, with dominance of four major groups: orthides and strophomenides (which had flourished previously in the Rhuddanian), pentamerides and atrypides (which became dominant in the Aeronian), and many newly evolved taxa, and occupied deeper water and wider ecological niches (level bottom and reef) than those in the Rhuddanian. Each of the continents has some endemic genera, but there is a greater proportion of them in South China, where some groups (such as the pentamerides and atrypides) are more diverse and others, such as the orthides, are much less common than elsewhere. Affinity indices (AI) show that two megaunits can be recognized: South China and Avalonia-Baltica-Laurentia (ABL); Siberia seems to have been loosely connected with ABL and even more loosely to South China presumably because of its geographical separation in the Northern Hemisphere. The separation of South China from the other megaunits is further supported by cluster analysis.

The Jou Puerta cave (Asturias, NW Spain): A MIS 3 large mammal assemblage with mixture of cold and temperate elements

The cave of Jou Puerta (Asturias, NW Spain), provided an interesting large mammal assemblage including cold-adapted elements like Coelodonta antiquitatis and Mammuthus primigenius, which are not frequent in Iberian sites. The chronology of the fossils ranges from 36.6 to 30.2Calka BP, corresponding to MIS 3, an episode characterized by fast climate changes, from extreme cold to temperate conditions.The origin of the bone accumulation is related to a natural trap, so most of the fossils were unusually well preserved.The woolly rhinoceros remains yielded one of the most numerous and well preserved populations of this species from the Iberian Peninsula, which allowed carrying out a detailed comparative anatomical study.The faunal composition of Jou Puerta was statistically analyzed in comparison with other Iberian and Western European fossil assemblages where C. antiquitatis and/or M. primigenius occurred. The results showed that temperate ungulate species are predominant at most of the Iberian assemblages, including Jou Puerta, resulting in a particular mixture of temperate and cold elements which does not reflect the typical faunal composition of the Eurasian mammoth steppe. This particular situation supports the idea that these cold taxa only reached the Peninsula occasionally, during the coldest episodes of the Pleistocene, resulting in a mixing of cold and temperate faunas, instead of a faunal replacing.

DNA barcoding reveals a largely unknown fauna of Gracillariidae leaf‐mining moths in the Neotropics

Higher taxa often show increasing species richness towards tropical low latitudes, a pattern known as the latitudinal biodiversity gradient (LBG). A rare reverse LBG (with greater richness towards temperate high latitudes) is exhibited by Gracillariidae leaf-mining moths, in which most described species occur in northern temperate areas. We carried out the first assessment of gracillariid species diversity in two Neotropical regions to test whether the relatively low tropical species diversity of this family is genuine or caused by insufficient sampling and a strong taxonomic impediment. Field surveys in six French Guianan and one Ecuadorian site produced 516 gracillariid specimens that were DNA barcoded to facilitate identification and to match larvae inside leaf mines with adults. Species delineation from sequence data was approximated using Automatic Barcode Gap Discovery and Refined Single Linkage Analysis through the Barcode Index Number system, and the proportion of described/undescribed species was estimated after comparison with types of 83% of described species. Locally, alpha-diversity far exceeds that of any known temperate fauna, with as many as 108 candidate species (59.3% as singletons) collected at one site, and with an estimated species richness lower bound of 240 species. Strikingly, at least 85% of the species collected as adults were found to be undescribed. Our sampling represents the most thorough survey of gracillariid species diversity in the Neotropics to date and the results from both our molecular and morphological analyses indicate that the current reverse LBG seen in this group is an artefact of insufficient sampling and a strong description deficit in the Neotropics.

High resolution Holocene record in the southeastern Bay of Biscay: Global versus regional climate signals

Core KS10b (North East Atlantic, 43°50′N, 2°03′W, water depth 550m) was recovered at a location of high sediment deposition, and hence includes a high-resolution palaeoclimatic record for the southeastern Bay of Biscay over the last 9000calyr BP. The effect of global and regional climatic forcing factors (e.g., orbital forcing, North Atlantic Oscillation: NAO) and their subsequent control on water temperature, sea-level, hydrology and continental influence were investigated by studying planktic and benthic foraminiferal faunas (>150μm), sedimentology, and stable isotopes. Results indicate probable episodic long-term incursions of the warm and salty Iberian Poleward Current (IPC) into the Bay of Biscay during the Holocene by the intermittent presence of subtropical Globigerinoides ruber in the otherwise temperate fauna. These incursions seem to be triggered by negative NAO-like conditions. Our data show five main climatic periods, which are in general agreement with the literature data on the climatic variability in the North Atlantic and the Iberian Peninsula: The early Holocene (~9000–7400calyr BP) is characterized by low sea-level, significant downslope transport, eutrophic benthic settings and high surface water productivity. These environmental characteristics are probably due to the general wet and warm climate under a prevailing negative NAO, increasing precipitation and river runoff and favouring the incursion of the IPC into the Bay of Biscay. The climatic optimum appears between ~7400 and 6000calyr BP under a generally positive NAO index. In the following (~6000–3500calyr BP), surface water cooling is matching a steep decline of the Northern Hemisphere summer insolation. Meanwhile, benthic settings are changing progressively towards present day trophic conditions. The time interval from ~3500 to 1800calyr BP encompasses the Iberian–Roman Humid period characterized by warm and humid conditions, and increasing primary production under a prevailing negative NAO index. The last 1800years were characterized by stable cool conditions, reflecting a change towards a positive NAO state.