Mammal Assemblages Research Articles

Fine‐scale variation in the medium and large‐sized mammal assemblage composition in northeastern Amazon: Drivers of β‐diversity and species interactions

AbstractUnderstanding fine‐scale assemblage composition patterns of mammals is important to increase ecological knowledge and support conservation actions. We investigated whether β‐diversity of medium and large‐sized mammals and its components (replacement and richness difference) are related to distance to major rivers, height above the nearest drainage (HAND), and vegetation height; and whether species interactions shape their spatiotemporal distribution. We used camera traps to monitor the mammal assemblage of the Tumucumaque Mountains National Park, Northeastern Amazon. The difference (Δ) in distance to major rivers and geographic distance between sites affected positively the total β‐diversity and both its components. ΔVegetation height affected total β‐diversity and species replacement, while ΔHAND affected richness differences, and to a lower extent, species replacement. We found evidence that spotted pacas (Cuniculus paca) and ocelots (Leopardus pardalis) adjust their spatiotemporal dynamics to escape from predation and to overlap with abundant prey, respectively. However, we did not find evidence that competition affects the spatiotemporal distribution of any other species. Vegetation height, distance to rivers and HAND influenced mammal assemblages probably through shaping the quality and amount of resources. Predation risk seems to be important in shaping the use of time and space by prey, while the distribution of prey is important for the use of time and space for predators. Furthermore, other niche differentiation mechanisms may explain why competition did not affect the species' spatiotemporal dynamics. We highlight the need to include different environmental contexts within protected areas to promote mammal diversity and conservation.

The last 20,000 years of climate change in the Iberian Peninsula characterized by the small-mammal assemblages

Climate and environments have undergone significant changes throughout the Earth's history, which are reflected in the faunal record. In that sense, small mammals provide valuable palaeoecological insights due to their close relationship with their associated environments. Our research investigates the dynamics of small mammal communities in the Iberian Peninsula from the Late Pleistocene to the Holocene, comparing regional environmental variations as well as anthropogenic impacts. Our review of the small mammal assemblages from 26 archaeological sites across the Iberian Peninsula revealed a differential response of the small mammal communities between the northern and southern areas. The colder climatic conditions which characterized the Late Pleistocene favoured the presence of mid-European species (e.g., Alexandromys (Oecomicrotus) oeconomus, Chionomys (Chionomys) nivalis) in northern regions until the Mid Holocene, while other taxa today restricted to northern Iberia (e.g., Arvicola amphibius, Microtus gr. (Euarvicola) arvalis, Sorex araneus-coronatus) reached southern regions during the Last Glacial Maximum but disappeared at the beginning of the Holocene period. Palaeoenvironmental reconstructions indicate predominantly open landscapes and colder climates in the Late Pleistocene, with increased forest cover during the Early-Mid Holocene in northern areas. In contrast, the southern regions exhibited more stable environments compared to the northern ones. Our results underscore how the great environmental diversity and interactions between natural and anthropogenic factors affected the composition of Iberian small mammal communities during the last 20,000 years. Most specifically, during the Late Holocene, biogeographical patterns of the small mammals are mostly affected by anthropic activities, with changes in the distribution of some species (Microtus (Iberomys) cabrerae), and the entrance of new ones (synanthropic species).

Linking functional and phylogenetic diversity to assess decay in ecosystem services induced by metacommunity‐level mammal extirpations

AbstractDefaunation is an increasingly pervasive process, reaching ever larger spatial scales worldwide. We integrated data on thousands of putative local mammal assemblages across the Neotropics into 518 metacommunities to predict the phylogenetic trait‐based effects of regional defaunation—here defined as meta‐extirpation (i.e. extinction at the metacommunity level)—on dozens of putative ecosystem services (ESs). Further, based on 1029 real‐world mammal assemblages coalesced into 236 metacommunities, we assessed the spatial extent of meta‐extirpations across the Neotropics, while empirically quantifying losses in ESs in comparison with putative scenarios. Using observed data, we also sought to understand changes in the mean body size of metacommunities for different dietary guilds. We examined patterns of mammal diversity, evaluated the erosion of ESs based on ecological networks and measured the relationships between diversity metrics and ESs via dissimilarity arrangements and generalized linear models. Meta‐extirpation regimes lead to a mean loss of 49.6% of the ESs provided by Neotropical mammals within metacommunities, whereas real‐world meta‐extirpations derived 47.2% of ES loss. We show that simulated meta‐extirpations penalizing large‐bodied species, induced the most severe losses in ESs. Regional‐scale meta‐extirpations lead to changes in the metabolic allometry and trophic structure of consumers, inducing significant metacommunity downsizing. We conclude that once‐thriving mammal‐mediated roles in natural ecosystems are fading, with significant consequences for human livelihoods. Many mammal populations have succumbed in several Neotropical ecoregions; so it is critical to protect representative fractions of Neotropical landscapes and regional species pools. Finally, we reinforce the appeal for effective conservation action, given that meta‐extirpations are already a global reality.

Functional and phylogenetic structure of mammals along elevational gradients in the Central and East Himalayas

BackgroundMountain ecosystems are critical hotspots of global biodiversity, yet the dynamics of community assembly along their elevational gradients are not well understood. This gap is primarily due to the complexity of environmental and biotic interactions that influence species distribution and community structure. Although extensive research has been conducted on certain taxa, such as small mammals and bats, comprehensive studies encompassing entire mammal assemblages are lacking. Our research aims to bridge this gap by examining the taxonomic, phylogenetic, and functional diversity, as well as the assemblage structures of mammal communities across elevational gradients in the Central and East Himalayas, exploring how diverse ecological and evolutionary processes impact community assembly.MethodsWe analyzed mammal elevational diversity patterns using species richness, functional diversity (FD), and phylogenetic diversity (PD). We compared the observed values of community structure, such as mean pairwise phylogenetic distance (MPD) and mean pairwise functional distance (MFD), with null-model corrected effect sizes to identify patterns and processes of community assembly. Using structural equation modeling and hierarchical partitioning, we investigated the relationships between climate, productivity, and various facets of diversity, describing the organization of each component across different elevations.ResultsTaxonomic, functional, and phylogenetic diversity generally decreased with elevation but showed varied patterns such as mid-elevation peaks, low-elevation plateaus, or monotonic declines across different regions. Richness-controlled functional diversity increased towards mid-low elevations and decreased at higher elevations in both regions, whereas richness-controlled phylogenetic diversity lacked consistent patterns. Phylogenetic structures tended to cluster from mid to high elevations, indicating closer relationships than those observed in random communities, likely due to significant environmental turnover near tree lines. Functional structure showed greater clustering at high elevations and increased over-dispersion at lower elevations, suggesting that species are more functionally similar than expected at higher elevations and more diverse at lower elevations. Our results revealed that environmental factors, evolutionary histories, and trait-driven ecological processes collectively shape species richness along these gradients.ConclusionsOur results showed incongruent community structures across phylogenetic and functional diversity. Generally, functional traits are closely linked to environmental conditions, reducing the chance of observing traits that are misaligned with their surroundings. Species with similar ecological roles or distinct evolutionary lineages often show convergent adaptations to highland environments. Additionally, our findings emphasize that community assembly varies with the biogeography and diversification history of individual mountain ranges, complicating the development of a generalized theory. Using multiple measures is important for accurate community structure assessments and effective conservation planning, as variable elevational patterns exist across different diversity dimensions.

Large mammal faunas and ecosystem dynamics during the late Middle to early Late Pleistocene at Grotta Romanelli (southern Italy)

Since the beginning of the XIX century, Grotta Romanelli gained recognition in European stratigraphy as an important site for the Late Pleistocene, due to the attribution of its basal sediments to the Last Interglacial (MIS 5e). Its abundant archaeological and paleontological findings made the cave a key reference point for the study of human evolution and faunal dynamics in the larger Mediterranean area over approximately the last 130,000 years. After a century, a new chronostratigraphic reassessment of Grotta Romanelli revised the timeframe of its lower levels, predating them to the late Middle Pleistocene.In this study, we re-evaluate selected historical museum collections from the so-called “lower complex” of Grotta Romanelli and examine the new fossils excavated between 2015 and 2022. We identify three main mammal assemblages associated with three different interglacial periods spanning the last 350,000 years. Our findings offer new insights into terrestrial ecosystems in Mediterranean Europe from the late Middle Pleistocene to early Late Pleistocene. Additionally, they provide valuable information to the biochronological framework of the European large mammal faunas.

Wilderness areas maintain mammal assemblage in subtropical mountain forests

Wilderness areas maintain mammal assemblage in subtropical mountain forests

Plio-Pleistocene hydrothermal events of the Baza Basin (Betic Cordillera, SE Spain) and their paleoecological implications

AbstractThe Lower Pliocene to upper Middle Pleistocene continental sedimentary infillings of the Baza Basin (Guadix-Baza Depression, SE Spain) are worldwide unique by their high stratigraphic completeness and exceptional preservation of their fossil record of terrestrial vertebrates. These sediments were deposited in fluvio-lacustrine environments and preserve huge assemblages of large mammals, including the oldest evidence of hominin presence in Western Europe at the late Lower Pleistocene sites of Barranco León and Fuente Nueva-3, dated to ∼1.4 Ma. Since latest Miocene times, the basin was subject to intense tectonic activity, showing sedimentary deposits originated from ancient hot springs. These hot springs were developed in a spatio-temporal network related to tectonic fractures, showing a higher concentration in the Orce sub-basin during Late Pliocene to Holocene times. Compositional analyses of cherts and other facies associated with these hot springs show geochemical and mineralogical markers linked to hydrothermal scenarios. The contribution of hot springs in the Baza Basin resulted in rich and productive biotopes, which supported a high diversity and biomass of terrestrial mammals. Similar geological, hydrochemical and ecological environments are found along hotspot lines in East Africa, the Levantine Corridor and the circum-Mediterranean realm. We hypothesize here that the presence of these hot springs corridors favored the dispersal of hominins and other large mammals during the Plio-Pleistocene, which led to the first hominin arrival in Europe.

Tuff deposits as preservational context for a Miocene continental mammal assemblage from Patagonia, Argentina

The CO tuff is one of the volumetrically largest volcaniclastic events so far recorded in the Early-Middle Miocene Santa Cruz Formation (Patagonian Argentina). It represents aeolian processes, related with westerlies, that reworked and transported enormous quantities of volcanic ash from the Andes into the continental interior that accumulated in fluvial floodplain deposits. This volcanic event generated a major environmental change at ∼17 Ma (Burdigalian) and hostile living conditions for the biota of the area, at least during the time of deposition. We performed here a comprehensive study including taxonomic, sedimentological, and taphonomic aspects of the mammal assemblage recovered from this tuff deposit. The assemblage is constituted by representatives of Microbiotheria, Paucituberculata, Folivora, Cingulata, Rodentia, Notoungulata, and Litopterna, reflecting a wide mammalian diversity. The formation of the assemblage can be linked to a normal attritional model, in which the death of the individuals and subsequent deposition and burial of their remains would have occurred gradually over time, simultaneously with the accumulation of volcanic ash, at the place of death or very close to it. The time between the death and burial would have been relatively short, in accordance with the rapid and continuous influx of volcanic ash to the depositional environment. This multidisciplinary study allows us to interpret and reconstruct the possible taphonomic pathways of the mammal assemblage and to provide novel information on this particular preservation context linked to volcanically-influenced fluvial environments.

Socio-environmental factors associated with small mammal assemblage and Leptospira prevalence in Suburban Areas of Terengganu, Malaysia

Objective: To examine the socio-environmental factors associated with the assemblage of small mammals and the prevalence of Leptospira pathogen in poor suburban communities of Terengganu, Malaysia. Methods: We trapped small mammals from 119 trapping points scattered around three suburban communities of Terengganu using sausage-baited live traps. On the average, we set up five traps for three nights at each sampling point during the trapping period. Kidneys of captured animals were harvested and processed for Leptospira investigation. Additionally, environmental survey was conducted at each trapping point to obtain information about possible variables supporting small mammal assemblage. We used a generalized linear model to evaluate the effect of different socio-environmental variables on small mammals’ assemblage. Results: A total of 89 small mammals, specifically, Rattus norvegicus (n=39), Rattus rattus (n=27), Rattus exulans (n=10), Suncus murinus (n=11), and Tupaia glis (n=2) were captured from 1 385 trap nights. Fourteen individuals (15.7%) of the captured animals tested positive for Leptospira bacteria using PCR detection. Results of our generalized linear model showed only residences bordering vacant lots as the variable positively associated with small mammal occurrence in the three study sites. Conclusions: Small mammal community, especially the often neglected species, could harbour and potentially contribute towards pathogenic Leptospira maintenance in the study sites. To adequately control small mammals’ population and subsequent human zoonoses transmission, it is critical to advocate and promote appropriate infrastructure and suburban services, together with good hygiene practices that can reduce the animals’ access to food and harborage.

Birds and mammals assemblages assessment in sub-Antarctic channels of the Kawésqar National Park and Reserve, southern Chile

Clarence Island and its inland channels are part of the Kawésqar National Park and Kawésqar National Reserve, an extensive wilderness area dominated by pristine sub-Antarctic environments and high marine biodiversity. During the summer and winter of 2020, the assemblages of birds and mammals were recorded in 10 sites, and these data, the following aspects were evaluated: 1) the sampling effort used with species accumulation curves and 2) the community structure of the assemblages with alpha and beta diversity. The total richness was 35 species of birds and 6 species of mammals, representing 17% of both groups documented for the sub-Antarctic Ecoregion of Magellan. During summer and winter, low and high values of species richness and abundance were registered, which modulated low and medium values of diversity. The moderate diversity was consistent with the beta diversity values from the Whittaker index, which on average indicates low species replacement in response to seasonal change. By considering that 20 % of the recorded species have high conservation risks, it can be concluded that this type of fauna survey contributes to improve the knowledge and dissemination of the current distribution of these species, and in future scenarios it will be useful to help predict local extinction events for anthropogenic or natural reasons.

New Early Cretaceous zalambdalestid stem placental mammal from Mongolia and evolution of Zalambdalestidae

ABSTRACT Prozalambdalestes cratodus gen. et sp. nov. is based on a fragmentary dentary from the Lower Cretaceous (Aptian–Albian) Khovoor locality in Gobi Desert, Mongolia. This is the largest eutherian in the Khovoor mammal assemblage. It shows dental specializations of Zalambdalestidae such as procumbent, ever-growing gliriform first lower incisor with restricted enamel and reaching posteriorly p5, and mesiodistally compressed lower molar trigonids. The enamel is restricted to the ventrolabial and ventrolingual sides of the mesial half of the incisor and the enamel band is higher on the labial side. The new taxon retains five lower premolars, with p1 smaller than p2 and p3 smaller than adjacent premolars, and the Meckelian groove. It also differs from other zalambdalestids by position of mental foramina (under p3 and p5), p1–3 obliquely set in dentary, and lower molar talonids wider than trigonids. Phylogenetic analysis places Prozalambdalestes gen. nov. in a polytomy with Albian Zhangolestes, Turonian Kulbeckia, and the clade of Campanian zalambdalestids from Mongolia and Kazakhstan. CT data in Zalambdalestes and comparison with Prozalambdalestes gen. nov. show that the four lower premolars in Zalambdalestes are p2, p3 (variable present), p4, and p5. Consequently, the three lower premolars of Barunlestes and Zofialestes are p2, p4, and p5. The other diagnostic characters of Zalambdalestidae are reviewed.

Use of native and human-modified habitats by different mammal guilds in West Africa

Over millennia, mammals have coexisted with humans across the forest-savannah mosaics characterising part of West Africa. While some savannahs have long been used for rice cultivation in Guinea-Bissau, savannas and forests are now being rapidly converted into cashew monocultures. To understand how species cope with such land-use changes, we investigated how mammals make use of forest patches, cashew orchards and rice paddies over two contrasting periods: early and late rainy season. Using camera-trapping, we examined mammal diversity and trophic guild activity across seven landscapes, each with one sampling site per habitat type in Northern Guinea-Bissau. Based on 937 records from 21 species, species richness and activity were similar across habitat types, but generally higher in the late-rainy season. In this season, species composition differed between the cashew orchards and rice paddies. At the guild-level, carnivore activity was lower in the rice paddies than in forests, while herbivore activity was lower in the cashew orchards in comparison to that in forests in the early-rainy season. The relatively similar assemblage-wide diversity across habitat types seems to be enabled by the high habitat heterogeneity, but likely offset by previous extinctions from the area. Yet, guild-level habitat use highlighted the fundamental role of forests to sustain functionally healthy mammal assemblages. Maintaining habitat heterogeneity, including patches of native forests, seems to be key in optimizing the long-term conservation of mammal diversity in rural West Africa.

Combined effects of climate and land-use changes on the alpha and beta functional diversities of terrestrial mammals in China.

Climate and land-use changes are predicted to impact biodiversity, threatening ecosystem services and functions. However, their combined effects on the functional diversity of mammals at the regional scale remain unclear, especially at the beta level. Here, we use projected climate and land-use changes in China to investigate their potential effects on the alpha and beta functional diversities of terrestrial mammals under low- and high-emission scenarios. In the current projection, we showed strong positive spatial correlations between functional richness and species richness. Functional evenness (FEve), functional specialization (FSpe), and functional originality (FOri) decreased with species richness, and functional divergence (FDiv) increased first and then plateaued. Functional beta diversity was dominated by its nestedness component, in contrast to the taxonomic facet. Potential changes in species richness are more strongly influenced by land-use change under the low-emission scenario, while under the high-emission scenario, they are more strongly influenced by climate change. Changes in functional richness (FRic) were inconsistent with those in species richness, with a magnitude of decreases greater than predicted from species richness. Moreover, mammal assemblages showed potential functional differentiation (FD) across the country, and the trends exceeded those towards taxonomic differentiation (TD). Our findings help us understand the processes underlying biodiversity responses to global changes on multiple facets and provide new insight for conservation plans.

A global assessment of nested patterns in insular mammal assemblages

A global assessment of nested patterns in insular mammal assemblages

Small mammal assemblages in heterogeneous landscapes at the Southern tip of Italian peninsula evidence clear eco-biogeographic patterns

We investigated the frequencies of sympatric small mammal species in 12 habitat-types located in the extreme south of the Italian peninsula (Calabria) using trapping techniques. Ten species were detected with Apodemus sylvaticus, the most abundant species. The assemblages of small mammal species recorded in the 12 selected habitat types revealed clear ecological and biogeographical patterns in the extreme southern tip of the Italian peninsula. Ecologically, we observed a clear dissimilarity between a guild of species linked to thermo-xerophilous habitat types and a comparable guild of mesophilous species linked to forest and sciaphilous habitat types. The differences among communities inhabiting in different habitat types also emerged in rarefaction curves, DCA analysis and Whittaker plots. Thus, all these sets of analyses were consistent in their interpretation of the variation of small mammal community structure along the gradient (β-diversity) among habitat types. From a biogeographical point of view, this is an apparent expression of a clear North–South gradient pattern that was already observed at the species level with Calabria being characterized by a strong impoverishment in species’ richness and diversity (“peninsula effect”). However, this rationale has been based so far on indirect data of small mammals preyed upon and recorded in owl’s pellets: the fact that a similar pattern was obtained also using small mammals recorded by traps indicates that the results were robust and generalizable. Ecological factors at the local scale and biogeographical factors at the peninsular scale could explain the community patterns that we observed in the present study.

Mammalian community responses in relation to anthropogenic disturbances and resource gradients in the shade coffee forest ecosystem of Southwestern Ethiopia

Understanding the effects of variation in resource availability and habitat disturbance on the ecology of mammals is vital for successful conservation management. In this study, we examined how human disturbances, resource availability and elevation gradients influence mammal assemblages in both managed coffee forest and natural forest of the Belete-Gera National Forest Priority Area, southwestern Ethiopia. We surveyed mammals using motion-detecting infrared camera traps in 90 locations for a total of 4142 camera days. We measured distance from main roads and settlements as disturbance factors, and distance from water sources, key grazing sites, and forest edges and woody plant diversity as resource variables. We assessed the mammal assemblages in coffee forest and natural forests using generalized linear models. Further, we used linear modelling to compare the relationships of mammal detection rates by feeding guilds and body size to resource variables. In total, we recorded 8815 videos identifying 23 different mammal species. The mammal assemblages in coffee forests were negatively associated with increasing distances from key grazing sites, water sources, and elevation. In contrast, the association with increasing distance from the road and woody plant diversity was positive. In addition, herbivores and large (25–200 kg) and very large (≥200 kg) mammals, were all negatively associated with increasing distance from the natural forest edges. With the conversion of natural forest to coffee forest and the intensification of coffee forest management, sustainable management of key grazing sites, water sources, and diverse woody plant species will be essential to the conservation of mammals. In addition, to ensure mammal conservation, adjacent natural forests around coffee forests should also be protected.

Species richness and ecological connectivity of the mammal communities in urban and peri-urban areas at Mexico City

Urban expansion has emerged as a pervasive driver of biodiversity loss in Mexican cities due to shifts in landscape composition and configuration. Hence, the preservation of forest cover, green spaces and isolated trees assume a critical role in conserving the biodiversity within urban areas. We compared mammal assemblages across 520 sites in Mexico City examining the impact of local vegetation and site characteristics (e.g., patch size, isolation distance) on diversity patterns. Then, we used a generalized linear model to evaluate the relationship between mammal assemblages (including both alpha and beta diversities) and the level of structural and functional connectivity across the landscape. We collected 5,063 records of 38 species from the sampled sites. Mammalian richness ranged from 1 to 9 spp./site, and the mean of taxonomic and functional (Functional Distance [MFD]) alpha diversities were 1.9 ± 1.3 spp./site and 0.41 ± 0.60 MFD/site, respectively. The average size of habitat fragments was 0.41 hectares, and the percent forest cover per site ranged from 0.5 to 100%. Both species and functional alpha diversities were different among the land-use and vegetation types (including protected vs. non-protected areas). There was a clear distinction (β value > 0.40) in species composition across the landscape, which was positively related to geographical distance and negatively related to connectivity between sites. We identified four main patches especially important to connectivity across the city and argue that conserving them is critical for restoring key components of biodiversity and ecosystem services in urban and peri-urban areas of Mexico City.

Relationships between Anthropogenic Activities and Distribution of Medium to Large Mammal Species Assemblage in Madi Wildlife Corridor: Implication for Biodiversity Conservation in Uganda

Wildlife corridors between protected areas increase connectivity by integrating populations into single demographic units, thereby increasing gene flows within populations and thus probability of survival. This study assessed the relationship between anthropogenic activities and mammal species assemblage within and around Madi wildlife corridor. The study adopted recce walks along a zig-zag line transect and straight line transect methods of game tracking. Global Position System (GPS) was used to map locations of direct mammal sightings, vocalizations, tracks, dung/droppings, diggings, carcasses, and skeletal remains of mammal species. Similarly, anthropogenic activities such as hunting using bow and arrows, rifles, trapping, tree cutting, charcoal burning, bush burning, cultivation, and settlements that seemed to influence assemblage of the mammals in the area of study were mapped. The result showed that the Madi wildlife corridor still contained diverse mammal species including but not limited to; the African Elephants (Loxodonta Africana sp.), Buffaloes (Syncerus caffer) Leopards (Panthera pardus), Spotted Hyena (Crocuta Crocuta), Northern Giraffe (Giraffa Camelopardalis), Uganda kob (Kobus kob thomasi), Hartebeest (Alcelaphus buselaphus) and Reedbuck (Redunca arundinum), which were comparable to that of the adjacent Murchison Falls National Park (MFNP). The relationship between anthropogenic activities and species assemblage showed a negatively skewed distribution of some of the large mammal species specifically Elephants, Giraffes, and Hippopotamus. The study recommends gazettement of a wildlife corridor between MFNP and East Madi Wildlife Reserve to promote wildlife connectivity between two adjacent ecosystem-protected areas in northern Uganda. As a long-term strategy for wildlife conservation, it is crucial to undertake a systematic assessment and prioritization and demarcation of wildlife corridors and development of a comprehensive action plan for securing them. We further recommend development of a national Wildlife Corridor Regulations to provide a framework for the sustainable conservation of biodiversity

Analysis of the Early Pleistocene small mammals from Pirro Nord 13 (Apricena, southern Italy) and their implications for reconstructing the palaeoenvironment of the early human occupation in Europe

The Pirro Nord quarry (Apricena, Foggia, southern Italy, 41°48′6″N, 15°23′5″ E) is a well-known palaeontological and archaeological locality comprising an abundant and diverse Early Pleistocene vertebrate assemblage of mammals, birds, amphibians, and reptiles related to the Late Villafranchian and Early Biharian mammal ages. In this study, we describe the small mammal assemblages (insectivores, rodents, and bats) excavated between 2010 and 2022 to reconstruct the palaeoenvironment surrounding the site using Habitat Weighting and the Bioclimatic model methods. The rodent assemblage comprises mostly Allophaiomys cf. ruffoi, Apodemus sp., and Hystrix refossa, whereas Eliomys cf. intermedius was reported for the first time. Insectivores includes Talpa gr. minor-caeca; Asoriculus sp.; Erinaceus praeglacialis; and Sorex sp. Bats are represented by Rhinolophus ferrumequinum, Rhinolophus gr. euryale-mehelyi, Myotis gr. myotis-blythii, Myotis sp., and Miniopterus schreibersii. Landscape reconstruction attested to the presence of a rich and diverse environment with open areas and forest patches surrounding the Pirro Nord 13 site. The climate was slightly colder than that of current times in the same area, with higher precipitation. The presence of different ecosystems near the sites constituted suitable conditions for the first human dispersion in Europe, as already revealed by evidence from Barranco León D, Atapuerca TE7–14, and Fuente Nueva 3 elsewhere on the Iberian Peninsula. The study of small mammal assemblages improves our understanding of the chronological boundaries of the human occupation of Pirro Nord 13, adding important information in the context of the first peopling of the Mediterranean region between 1.6 and 1.3 million years ago.

The Hasli Formation of the Irchel Plateau – A key record for older Early Pleistocene interglacial sediments in northern Switzerland

In the Alpine region of Central Europe, terrestrial Early Pleistocene deposits with preserved faunal and botanical remains are rare. The predominantly gravelly Höhere Deckenschotter (HDS) deposits of northern Switzerland and adjoining south-western Germany are considered the oldest Quaternary sediments in the northern Alpine Foreland, linked with the first extensive Quaternary Alpine glaciations.This multidisciplinary study investigates the Hasli Formation (HF), a unique silty unit with well-preserved biological remains within an HDS sequence at the Irchel Plateau north of Zürich, providing new climatic and environmental data for these exceptional deposits, as well as crucial information about their age. Systematic mapping of the HF, in addition to the underlying and covering gravel units, has been coupled with sedimentary logging and biostratigraphic analysis at several sites. The HF is present over an area c.4 by up to 1.4 km, and where studied is 1.6–6.2 m thick. The sediments and biological material are indicative of overbank deposits accumulating within the damp floodplain of a large meandering river.The recovered small mammal remains are from eight arvicolid species or genera, including Mimomys pliocaenicus, M. reidi/tigliensis and Clethrionomys cf. kretzoii, which became extinct c.1.8 Ma, and Pliomys episcopalis/simplicior, which first appeared c.2 Ma ago. The over 75k identified molluscs, include c.72k coming from 89 terrestrial species and over 3k from 28 aquatic taxa. The molluscan faunas from all locations where the HF has been studied share important biostratigraphic marker species, and indicate analogous climatic and environmental conditions. The marker species include several that became extinct during the Early Pleistocene, of which Clausilia stranzendorfensis and Cochlostoma salomoni, present throughout the HF, are the most important as they disappeared c.1.8 Ma. Many marker species have modern or palaeo-distributions that lie far to the west, south and east of the Swiss Plateau, showing that the climate was much warmer than today, typical for the Tiglian warm stage. The alluvial floodplain was covered by rather dense, mature woodland.Amino acid (AA) analysis shows that molluscan remains from the HF are among the oldest of the Quaternary shell material studied from across the Swiss Plateau. Palaeomagnetic data shows a change from reversed to normal polarity within the upper part of the HF. When combined, the small mammal and molluscan remains, palaeomagnetic measurements, AA geochronology and sedimentary data, suggest an age of 2.1–1.8 Ma for the HF. Recently produced cosmogenic dates bracket the age of the HDS gravels beneath the HF to depositional periods between 2.6 and 0.9 Ma, with the youngest ages being in disagreement with our findings. The abundance and diversity of the molluscs from the Irchel Plateau, with several rare extinct species, together with a notable small mammal assemblage, make this a key palaeontological site and an important reference point for European Quaternary biostratigraphy.