-
An endemic species flock of Candonidae Kaufmann, 1900 (Crustacea, Ostracoda) from wells in Benin (West Africa), with the description of a new subfamily, a new genus and five new species
-
Between 2015 and 2022, over 200 wells were sampled in four catchment areas of Benin, using both Cvetkov plankton nets (funnel 200 μm mesh size, 150 μm below valve) and baited traps. As artificial wells serve as ecotones (interfaces between surface and groundwater ecosystems), the ostracod fauna is mostly represented by two families; Cyprididae (mainly epigeic) and Candonidae (hypogeic). Here, we describe a new subfamily of Candonidae from the wells in Benin, the Benincandoninae subfam. nov. Hotèkpo & Martens, represented by one genus, Benincandona gen. nov. Hotèkpo & Martens. we found 35 species belonging to this evolutionary radiation, of which we describe five new species: Benincandona martini gen. et spec. nov. Hotèkpo & Martens, B. ibikounlei gen. et spec. nov. Hotèkpo & Martens, B. sakitii gen. et spec. nov. Hotèkpo & Martens, B. cebios gen. et spec. nov. Hotèkpo & Martens and B. trapezoides gen. et spec. nov. Hotèkpo & Martens. The new subfamily and genus are characterised by a unique combination of characters, such as a seven-segmented antennula and a caudal ramus with a fully developed ramus, a single apical (anterior) claw and three short setae. Species within the genus can be distinguished by their carapace and hemipenis morphology, together with some limb characteristics. whereas extensive subterranean candonid radiations have previously been reported from Europe, North and Central America and Northwest Australia (Pilbara), this is the first time such a vast radiation of subterranean candonids is reported from (west) Africa.
Located in
Library
/
RBINS Staff Publications 2024
-
Evidence for a single population expansion event across 24,000 km: the case of the deep‑sea scavenging amphipod Abyssorchomene distinctus
-
Anthropogenic activities such as mining pose a putative threat to deep-sea ecosystems and baseline studies of key indicator species are required to assess future loss of biodiversity. We examined population genetic structure, connectivity, cryptic diversity and phylogeography of the deep-sea scavenging amphipod, Abyssorchomene distinctus, using DNA sequence data (mitochondrial COI and nuclear 28S genes) from 373 specimens collected from six abyssal basins. We observed a striking absence of cryptic diversity, suggesting a single, widely distributed species in the Pacifc and Indian Ocean. A single event of population expansion across distances up to 24,000 km is further supported by a main ancestral haplotype in the star-like shaped COI haplotype network, a skewed nucleotide mismatch distribution and deviations from evolutionary neutrality tests. In the Pacifc, A. distinctus showed weak genetic population structure and low diferentiation between the basins of the Clarion-Clipperton Zone and the DISCOL Experimental Area, suggesting a possible higher chance of recovery from deep-sea mining impacts. However, since our data indicate a single recent historic population expansion event, A. distinctus populations will likely be afected to unknown extents, as the exact drivers shaping distribution and dispersion of A. distinctus are still unclear
Located in
Library
/
RBINS Staff Publications 2024
-
The Ostracod Clumped-Isotope Thermometer: A Novel Tool to Accurately Quantify Continental Climate Changes
-
This study presents a methodological advancement in the field of clumped-isotope (∆47) thermometry, specifically tailored for application to freshwater ostracods. The novel ostracod clumped isotope approach enables quantitative temperature and hydrological reconstruction in lacustrine records. The relationship between ∆47 and the temperature at which ostracod shell mineralized is determined by measuring ∆47 on different species grown under controlled temperatures, ranging from 4 ± 0.8 to 23 ± 0.5ºC. The excellent agreement between the presented ∆47 ostracod data and the monitored temperatures confirms that ∆47 can be applied to ostracod shells and that a vital effect is absent outside the uncertainty of measurements. Results are consistent with the carbonate clumped-isotope unified calibration (Anderson et al., 2021, https://doi.org/10.1029/2020gl092069), therefore, an ostracod-specific calibration is not needed. The ostracod clumped-isotope thermometer represents a powerful tool for terrestrial paleoclimate studies all around the world, as lakes and ostracods are found in all climatic belts.
Located in
Library
/
RBINS Staff Publications 2024
-
Multiple genetic species in a halophilic non-marine ostracod (Crustacea)
-
The discovery of animal genetic (mostly also cryptic) species has known an exponential increase since molecular techniques became available. Also in non-marine ostracods (small, bivalved crustaceans with an excellent fossil record), several morphospecies have been shown to comprise several genetic species. Here, we screen 13 populations from Central Europe and the circum-Mediterranean region of the halophilic continental ostracod species Heterocypris salina with DNA sequences from a mitochondrial (COI) and a nuclear (28S) marker. We apply four species delimitation methods to show that this nominal species consists of four genetic species in both DNA datasets, and that these two sets of genetic species show mitonuclear discordance. Most investigated specimens belonged to one of these four genetic species. There was no clear correlation between geographic and genetic distances, but we found that, apart from historical processes, environmental factors such as ecoregion, seasonality and salinity might have been important drivers shaping discrete genetic diversity. Following the palaeontological literature, the H. salina species cluster is at least 11–9 Myr old.
Located in
Library
/
RBINS Staff Publications 2024
-
The cranium and dentition of Khirtharia (Artiodactyla, Raoellidae): new data on a stem taxon to Cetacea
-
Raoellid mammals are small artiodactyls from the Eocene of Asia, hypothesized to be closely related to stem Cetacea. Knowledge of the cranial and dental morphology of Raoellidae comes mostly from one species, Indohyus indirae. Here we describe new material of another raoellid genus, Khirtharia, based on material retrieved from the Kalakot area, Jammu and Kashmir. This new material, comprising an almost complete, lightly deformed cranium and a partial snout with associated partial mandible, greatly adds to our knowledge of raoellid morphology. It highlights the similarity of cranial characters with Indohyus, such as a long snout with raptorial incisors, a thick and narrow supraorbital region, a strong postorbital constriction, a triangular shaped braincase, and a thickened medial wall to the auditory bulla (involucrum). The new specimen is similar to Indohyus cranially but differs dentally in being more bunodont. The presence of these traits in two different raoellid genera suggests they may be present more broadly across Raoellidae. These characters are also observed in early cetaceans, highlighting the need to investigate their phylogenetic impact. Some cranial features support aquatic habits of members of this family.
Located in
Library
/
RBINS Staff Publications 2024 OA
-
Endocranial anatomy and phylogenetic position of the crocodylian Eosuchus lerichei from the late Paleocene of northwestern Europe and potential adaptations for transoceanic dispersal in gavialoids
-
Eosuchus lerichei is a gavialoid crocodylian from late Paleocene marine deposits of northwestern Europe, known from a skull and lower jaws, as well as postcrania. Its sister taxon relationship with the approximately contemporaneous species Eosuchus minor from the east coast of the USA has been explained through transoceanic dispersal, indicating a capability for salt excretion that is absent in extant gavialoids. However, there is currently no anatomical evidence to support marine adaptation in extinct gavialoids. Furthermore, the placement of Eosuchus within Gavialoidea is labile, with some analyses supporting affinities with the Late Cretaceous to early Paleogene “thoracosaurs.” Here we present novel data on the internal and external anatomy of the skull of E. lerichei that enables a revised diagnosis, with 6 autapormorphies identified for the genus and 10 features that enable differentiation of the species from Eosuchus minor. Our phylogenetic analyses recover Eosuchus as an early diverging gavialid gavialoid that is not part of the “thoracosaur” group. In addition to thickened semi-circular canal walls of the endosseous labyrinth and paratympanic sinus reduction, we identify potential osteological correlates for salt glands in the internal surface of the prefrontal and lacrimal bones of E. lerichei. These salt glands potentially provide anatomical evidence for the capability of transoceanic dispersal within Eosuchus, and we also identify them in the Late Cretaceous “thoracosaur” Portugalosuchus. Given that the earliest diverging and stratigraphically oldest gavialoids either have evidence for a nasal salt gland and/or have been recovered from marine deposits, this suggests the capacity for salt excretion might be ancestral for Gavialoidea. Mapping osteological and geological evidence for marine adaptation onto a phylogeny indicates that there was probably more than one independent loss/reduction in the capacity for salt excretion in gavialoids.
Located in
Library
/
RBINS Staff Publications 2024 OA
-
Timing of intercontinental faunal migrations: Anguimorph lizards from the earliest Eocene (MP 7) of Dormaal, Belgium
-
Here we report on anguimorph lizards from the earliest Eocene (MP 7) of the Dormaal locality in Belgium, from the time of the warmest global climate of the past 66 million years. Several clades can be identified in this site: Glyptosauridae, Varanidae, and Palaeovaranidae. Our study focuses on glyptosaurid specimens previously reported from the site, some of which had been provisionally described as a new species,?Placosaurus ragei, and some assigned to an unnamed Placosauriops-like ‘melanosaurine’. Our study presents data on new material, including an almost complete glyptosaurine frontal that has enabled us to assign much of the previously described material to a single genus and species. The specimens that had been assigned to both ?P ragei and the ‘melanosaurine’ share apomorphies (flat osteoderms and chevron-shaped osteoderms) with Gaultia, a glyptosaurid previously known from the earliest Eocene of Wyoming, USA. The Dormaal material represents the first record of this genus outside North America. In fact, the only potential evidence of the occurrence of ‘Melanosaurinae’ in Dormaal might be a single isolated vertebra described here. Here we also describe previously unfigured material of Saniwa and palaeovaranids from Dormaal. The presence of previously reported helodermatids cannot be supported in this Belgian site.
Located in
Library
/
RBINS Staff Publications 2024 OA
-
Revision of the Eurybrachidae XVIII. The Australian genus Olonia Stål, 1862: Four new species, new records and biological data (Hemiptera: Fulgoromorpha)
-
Located in
Library
/
RBINS Staff Publications 2024
-
Agropastoral and dietary practices of the northern Levant facing Late Holocene climate and environmental change: Isotopic analysis of plants, animals and humans from Bronze to Iron Age Tell Tweini
-
One of the largest isotopic datasets of the ancient Eastern Mediterranean region is evaluated, based on plants (n = 410), animals (n = 210) and humans (n = 16) from Tell Tweini (Syria). Diachronic analysis of plant and faunal specimens from four main periods of occupation: Early Bronze Age (2600–2000 BC), Middle Bronze Age (2000–1600 BC), Late Bronze Age (1600–1200 BC) and Iron Age (1200–333 BC) were investigated. Mean Δ13C results from seven plant species reveal emmer and free threshing wheat, olives, bitter vetch, rye grass and barley were adequately or well-watered during all periods of occupation. The grape Δ13C results suggest excellent growing conditions and particular care for its cultivation. The δ15N results indicate that especially the emmer and free threshing wheats received some manure inputs throughout the occupation sequence, while these were likely further increased during the Iron Age, encompassing also the olive groves and grape vineyards. Generally, domestic animals (cattle, sheep, goats) had C3 terrestrial diets and were kept together in similar environments. However, some animals consumed significant amounts of marine or C4 plants, possibly from disturbed habitats due to land use pressure or salt tolerant grasses and shrubs from wetland environments, which were recorded in the direct vicinity of the site. Middle Bronze Age humans consumed a C3 terrestrial diet with no measurable input from C4, freshwater or marine protein sources. Interestingly, the human diet was relatively low in animal protein and appears comparable to what is considered today a typical Mediterranean diet consisting of bread (wheat/barley), olives, grapes, pulses, dairy products and small amounts of meat. The combined isotopic analysis of plants, animals and humans from Tell Tweini represents unbroken links in the food chain which create unparalleled opportunities to enhance our current understanding of environmental conditions, climate change and lifeways in past populations from the Eastern Mediterranean.
Located in
Library
/
RBINS Staff Publications 2024
-
Host lifestyle and parasite interspecific facilitation mediate co- infection in a species-poor host–parasite system
-
Located in
Library
/
RBINS Staff Publications 2024
