Cretaceous amber inclusions of Spain and Myanmar demonstrate early diversification and wide dispersal of Cephenniitae (Coleoptera: Staphylinidae: Scydmaeninae)

The taxonomic status of previously misplaced species of an ant-like stone beetle from Spanish amber (Albian) is clarified. Specimens of Kachinus magnificus (originally placed as incertae sedis within Scydmaenitae) were re-examined and their characters were found different from those of the type species of Kachinus from Myanmar amber. Consequently, Archeutheia gen. nov. is proposed to accommodate the Spanish species, resulting in Archeutheia magnifica comb. nov. Moreover, in a comprehensive phylogenetic analysis Archeutheia was placed as a sister group to extant Eutheia, within the tribe Eutheiini of Cephenniitae. A specimen of an undetermined genus from Myanmar amber clearly belonging in Cephenniini is also recorded. Both taxa represent the first definite Cretaceous Cephenniitae, a supertribe whose recent members are distributed on all continents but are especially diverse in the Oriental and East Palaearctic regions. This finding demonstrates a diversification of two presently most species-rich tribes of Cephenniitae already in Early Cretaceous. Archeutheia is strikingly similar to the extant species of Eutheia and Veraphis, showing male dimorphic characters (modified protrochanters) and antennal cavities characteristic of Palaearctic Eutheiini. This fact suggests a long morphological stability in the supertribe. A previously proposed hypothesis of an early presence of the Cephenniitae in the Northern Hemisphere is for the first time supported by the fossil record, and the palaeolocalities (western Europe and Southeast Asia) demonstrate a wide distribution of Cephenniitae in the Cretaceous and an early split of its ancestral lineage.     

Magnetostratigraphy and lithostratigraphy of the Laño vertebrate-site: Implications in the uppermost Cretaceous chronostratigraphy of the Basque-Cantabrian Region

Here we present the magnetostratigraphic dating of the Laño locality (Condado de Treviño, northern Iberian Peninsula), one of the most noteworthy Campanian-Maastrichtian vertebrate sites of Europe. A composite section of 75 m thickness (Laño quarry) constructed from multiple, overlapping profiles and a continuous one (Faido) have been sampled for magnetostratigraphy. Thermal demagnetization techniques were systematically applied to 161 standard specimens and allowed characterizing the characteristic remanent magnetism, mostly carried out by magnetite. The palaeomagnetic signal is slightly scattered due to variety of lithologies, but the primary character can be guaranteed, since the normal and reverse directions are pseudo antiparallel; 346, 28 (α₉₅: 11.9°, k: 5.3) and 175, −35 (α₉₅: 16.4°, k: 4.6). Reliable samples allowed us to build the local polarity sequence made of eight magnetozones that has been used to correlate to the Global Polarity Time Scale. The age of the lower part of the Laño-village succession is basal late Campanian (Hoplitoplacenticeras marroti ammonite zone) and fits with the long reversed zone that must correlate to Chron C33r. The pattern of magnetozones allows tracking the section up to C30r at the upper part of the profile. In this correlation, the Laño vertebrate site is regarded as latest Campanian in age as it falls within the C32n (≈72–73.5 Ma). The combined lithostratigraphic and magnetostratigraphic analyses have yielded additional conclusions regarding the vertebrate assemblages that are representative of the Late Campanian of the Iberian Peninsula, in addition to highlight an older occurrence in Europe of some vertebrate groups such as salamandrid lissamphians and anguid lizards (or amphisbaenians).     

A new climatology of maximum and minimum temperature (1951–2010) in the Spanish mainland: a comparison between three different interpolation methods

This study presents a new climatology of monthly temperature for mainland Spain (1951–2010), performed with the highest quality and spatially dense, up-to-date monthly temperature dataset available in the study area (MOTEDAS).

Three different interpolation techniques were evaluated: the Local Weighted Linear Regression (LWLR), the Regression-Kriging (RK) and the Regression-Kriging with stepwise selection (RKS), a modification of RK. The performances of the different models were evaluated by the leave-one-out validation procedure, comparing the results from the models with the original data and calculating different error measurements.

The three techniques performed better for T_max than for T_min, and for the cold, rather than warmer months, also at lower altitude than highland areas. The best results were achieved with LWLR applied for the first time on temperatures in the Spanish mainland. This method improved the accuracy of the temperature reconstruction with respect to RK and RKS.

We present a collection of T_max and T_min monthly charts, using the same temperature legend to prevent any visual bias in the interpretation of the results. The dataset is available upon request.     

A low resolution map of Europa from four occultations by Io

Analysis of three occultations of JII (Europa) by JI (Io) has resulted in a preliminary reflectivity map of JII for the hemisphere centered on longitude 324°, a measurement of 1483±20 km for the radius of JII, estimates of the event impact parameters, determination of the mid event times, and a visual geometric albedo, p_ν = 0.74, for JII. A fourth occultation light curve was used after derivation of the results to confirm their validity.     

Life Cycle of Liocarcinus arcuatus (Brachyura: Portunidae) in the Ría de Arousa (Galicia, NW Spain): Role of Beach and Mussel Raft Culture Areas

Abstract. The population biology of the portunid crab Liocarcinus arcuatus is analyzed over a yearly cycle in beach zones and mussel raft culture areas in the Ria de Arousa.
The breeding cycle of this species has two annual peaks, which result in two annual cohorts that are recruited in different areas. The growth rate is higher in the group settled in spring than in autumn, and, especially, in the culture areas compared with the beach zones. There are movements from the beach zones to the raft polygons related to reproductive and feeding behavior as well as growth. The role of mussel culture in the dynamics of this species is discussed.     

Nitrogen cycling in deep-sea sediments of the Porcupine Abyssal Plain, NE Atlantic

Rates of transformation, recycling and burial of nitrogen and their temporal and spatial variability were investigated in deep-sea sediments of the Porcupine Abyssal Plain (PAP), NE Atlantic during eight cruises from 1996 to 2000. Benthic fluxes of ammonium (NH₄) and nitrate (NO₃) were measured in situ using a benthic lander. Fluxes of dissolved organic nitrogen (DON) and denitrification rates were calculated from pore water profiles of DON and NO₃, respectively. Burial of nitrogen was calculated from down core profiles of nitrogen in the solid phase together with ¹⁴C-based sediment accumulation rates and dry bulk density. Average NH₄ and NO₃-effluxes were 7.4 ± 19 μmol m⁻² d⁻¹ (n = 7) and 52 ± 30 μmol m⁻² d⁻¹ (n = 14), respectively, during the period 1996–2000. During the same period, the DON-flux was 11 ± 5.6 μmol m⁻² d⁻¹ (n = 5) and the denitrification rate was 5.1 ± 3.0 μmol m⁻² d⁻¹ (n = 22). Temporal and spatial variations were only found in the benthic NO₃ fluxes. The average burial rate was 4.6 ± 0.9 μmol m⁻² d⁻¹. On average over the sampling period, the recycling efficiency of the PON input to the sediment was 94% and the burial efficiency hence 6%. The DON flux constituted 14% of the nitrogen recycled, and it was of similar magnitude as the sum of burial and denitrification. By assuming the PAP is representative of all deep-sea areas, rates of denitrification, burial and DON efflux were extrapolated to the total area of the deep-sea floor (>2000 m) and integrated values of denitrification and burial of 8 ± 5 and 7 ± 1 Tg N year⁻¹, respectively, were obtained. This value of total deep-sea sediment denitrification corresponds to 3–12% of the global ocean benthic denitrification. Burial in deep-sea sediments makes up at least 25% of the global ocean nitrogen burial. The integrated DON flux from the deep-sea floor is comparable in magnitude to a reported global riverine input of DON suggesting that deep-sea sediments constitute an important source of DON to the world ocean.     

Seasonal variation in the concentrations of nutrients in two green macroalgae and nutrient levels in sediments in the Rías Baixas (NW Spain)

Seasonal monitoring of the levels of carbon, nitrogen and phosphorus in two green macroalgae (Ulva and Enteromorpha) was carried out at 22 sampling sites in four embayments (rías) on the northwest coast of Spain. Sediments were also analysed to determine the concentrations of these elements as well as organic matter, organic carbon, iron and texture. In addition, accumulations of Ulva were monitored. Nitrogen levels in algae were similar to those found in comparable studies, whereas carbon concentrations were generally higher and those of phosphorus were lower. As a result the macroalgae were relatively enriched by carbon and nitrogen compared with phosphorus. Seasonal variations in algal tissue nitrogen and phosphorus followed the usual pattern for temperate zones, with minimum levels in summer and maximum levels in winter. Variations in carbon concentrations were much less accentuated. The low levels of P in the algae appear to indicate limitation by this element, however, comparison of the monthly changes in nitrogen and phosphorus in Ulva with the critical concentrations of these elements suggests dual nutrient limitation in this alga in summer. By contrast, the sediments were more enriched by phosphorus; high retention of this element by the sediment may explain the low levels in algae. The highest accumulations of Ulva occurred in spring and summer; hydrodynamic factors appeared to be important in determining the extent of these accumulations.