Caves are unique, extreme ecosystems, hosting diverse microbial communities adapted to these ecological niches that exhibit important roles in supporting underground ecosystems. One of the sources of caves microbiome is represented by bat guano deposits. The very diverse diet of Chiroptera (mainly insectivory, but also frugivory, nectarivory, hematophagy, and carnivory) (Graham, 1994) influences the diversity of their microbiota.

Mesoniscus Carl, 1906 is a genus of terrestrial isopods (Isopoda: Oniscidea), from the family Mesoniscidae, section Microcheta. The genus is the only member of the family and contains two cavernicolous species, with a distribution strictly limited to the Alpino-Carpathian chain.

The excessive use of herbicides has led to their accumulation in the environment, resulting in severe ecological and health consequences. Thus, the development of efficient on-site methods to detect herbicides is becoming increasingly important. Electrochemical biosensors that rely on the inhibition of photosynthesis of microorganisms by herbicides have emerged as an attractive alternative to conventional analytical techniques due to their high level of specificity, sensitivity, speed, and relatively low cost (Tucci et al., 2019). Phototrophic microorganisms adapted to cold environments may serve as ideal models for developing biosensors that can operate effectively in low-temperature environments, such as seawater. In this context, our study aimed to explore the potential of microorganisms isolated from Scărișoara Ice Cave for developing cold-active electrochemical biosensors for herbicides.

Fungi are a critical component of the carbon cycle, having an important role in the decomposition of soil organic matter. During the decomposition process, CO2 is released in the soil where it dissolves into infiltrating water, forming carbonic acid. In carbonate settings, the resulting carbonic acid is the main driver behind karst formation and speleothem deposition. The isotopic composition of carbon in CO2 is one of the main factors affecting the δ13C in speleothems, an important paleoenvironmental proxy.

The Mangalia town region in Southern Dobrogea, Romania, conceals dark, isolated, and sulfide-rich overlapping aquifers hiding intriguing and complex hydrogeological characteristics (Marin & Nicolescu, 1993; Sarbu, 2000). This unique ecosystem is sustained by a high level of primary production through chemosynthesis, mainly supported by chemoautotrophic bacteria and protozoa that derive their energy from chemical reactions with inorganic molecules such as hydrogen sulfide, elemental sulfur, and ammonia under low oxygen or anaerobic conditions (Sarbu et al., 1994, 1996; Engel, 2007; Kumaresan et al., 2014; Sarbu et al., 2019). The Upper Sarmatian sulfidic mesothermal aquifer, the focus of the current study, which is accessible through the old handdugwells (sulfidic and non-sulfidic water), and the Movile Cave provide a suitable habitat for a diverse community of cyclopoid crustaceans (eight species) with a preponderance of stygobites (75%), from the following genera: Acanthocyclops Kiefer, 1927, Diacyclops Kiefer, 1927, Tropocyclops Kiefer, 1927, and Eucyclops Claus, 1893. The spatial distribution of the identified species does not indicate a distinct affinity for a specific type of water, sulfidic or non-sulfidic.

Ice caves can be found at mid-to-high northern latitudes, with elevations ranging from 0 to over 3000 meters above sea level (Perșoiu et al., 2021). These caves are home to rare and endemic species, as well as glacial relicts that require cold microclimates to survive (Iepure, 2018). The extremely low temperatures in these caves have played a significant role in shaping the structure of both terrestrial and aquatic communities (Iepure, 2018)

Cave sediments are natural repositories that store geochemical and palaeobiological information and sometimes archaeological materials, thus providing evidence of past changes in the environment and clues of human activities over long temporal scales (Springer, 2019). Here we aimed to reconstruct the Holocene ecosystem dynamics using poorly studied, non-disturbed cave sediments from important sites with known hominin occupation (Ciur Izbuc and Toplița de Vida) located in the Apuseni Mountains (western Romania, Fig. 1).

The diet of large mammals can be studied based on the carbon and nitrogen isotopic composition of bone collagen. The stable isotope composition of these elements undergoes fractionation along the food chain and one can distinguish the trophic level and food source of mammals based on their isotopic signature (Bocherens & Drucker, 2003).

This study aims to compare stable isotopes of carbon and nitrogen in wolves and domesticated dogs populations from various paleontological and archaeological sites from Romania.

The Quaternary fauna of Romania contained several species belonging to the Vulpes genus (family Canidae, subfamily Caninae, tribe Vulpini), namely Vulpes vulpes, Vulpes corsac, and Vulpes lagopus. The most diverse Vulpes fauna reported so far from Romania was discovered at La Adam Cave and contains all three species mentioned above (Dumitrescu et al., 1963, 1965). Nevertheless, the fox specimens from this site were not systematically studied. We propose here to identify the individuals belonging to these three species, using the morphology of the first lower molar (m1), following the approach of Gimranov et al. (2015).

Pleistocene climate changes have led to vegetation type and distribution changes. In Central-Eastern Europe, long paleoenvironmental archives are scarce, thus for this region environmental reconstructions on glacial/interglacial time scales are not available.

In southern Dobrogea, around the town of Mangalia, there is an important karst area where large dolines are dominating the landscape. The presence of mesothermal groundwater rich in H2S and CH4 created conditions for the development of hypogene karst (Sârbu & Lascu, 1997; Onac & Drăgușin, 2017; Drăgușin et al., 2021), while also providing the basis of a chemoautotrophic ecosystem (Sârbu & Lascu, 1997; Sârbu et al., 2019; Brad et al., 2021).

The aim of the osteometric analyses is to assess the limit of the dimensional variation for a certain species during a certain period. In Quaternary palaeontology, where the fossils have better occurences (i.e. when comparing with the Mesosoic era), especially in cave bears - whose bones are the most encountered among all the mammals found in cave deposits - the osteometric comparisons between populations from different sites (either contemporaneous orwith different age)may indirectly provide information about the palaeobiology of this species and climate changes of the ecosystems where these animals lived (Tsoukala & Grandald’Anglande, 2002).