Preliminary taphonomic approach to “Lo Hueco” palaeontological site (Upper Cretaceous,Cuenca, Spain)

“Lo Hueco” encloses an extraordinary upper Campanian-lower Maastrichtian fossil assemblage, composed mainly of vertebrates but also plants and invertebrates, and concentrated in a sandy channel structure (C), two grey marly mudstone levels (G1 and G2) and the lower part of a red marly mudstone level (R2). Regarding biostratinomy, the C structure (interpreted as a distributary sandy channel) contains numerous highly altered and randomly distributed macrofossils. The G1 level (the proximal part of a flooded muddy plain) preserves several totally or partially articulated specimens, mainly sauropods, with low degree of scattering and preferred orientation with respect to C. The G2 level (the distal part of a flooded muddy plain) and the lower part of the R2 level (the dried part of a muddy plain) contain numerous rarely articulated and randomly scattered macrofossils. Concerning fossil diagenesis, macroscopically, most bones present a first infilling of gypsum in spongy cavities, a ferruginous crust over outer surfaces and a second precipitation of gypsum over outer surfaces and eventually crossing the ferruginous crust and the first infilling of gypsum. Microscopically, most bones from the C structure and the G1 level additionally show radial microcracks in secondary osteons and ferruginous rings in Haversian channels. Given their particular geological and taphonomic characteristics, the C structure, the G1 and G2 levels and the lower part of the R2 level constitute four distinct taphofacies or bonebeds.     

The first Tanyderidae (Diptera) from Lower Cretaceous Álava amber (Spain)

A new genus and species, Espanoderus barbarae gen. et sp. nov., belonging to the family Tanyderidae (Diptera, Nematocera), is described from Lower Cretaceous amber of Spain (Álava amber). The new genus is the smallest member of Tanyderinae and the first member of the family from the Álava amber. The position of the new genus in a phylogenetic tree of Tanyderidae is presented.

http://zoobank.org/urn:lsid:zoobank.org:pub:EC3284BA-C07F-48AC-8AF5-4F9D2EF4EA6C     

Environmental significance of gypsum-bearing layers at the “Lo Hueco” paleontological site (Upper Cretaceous,Cuenca, Spain): petrography,fluid inclusions,and isotopic relations

“Lo Hueco” (Cuenca, Spain) is an upper Campanian–lower Maastrichtian Fossil-Lagerstätte that has provided more than 8,500 well-preserved macrofossils, including titanosaur sauropod dinosaurs. Although the facies and fossil record point to both fresh and brackish or marine water influences, a detailed study of the sulphate-bearing layers of the site through petrography, fluid inclusions, and isotopes has been undertaken to evaluate the possible marine influence. The two main sulphate units of the “Lo Hueco” site consist chiefly of bimodal micro- to meso- lenticular gypsum crystals that grew displacively in a clayey-carbonate sediment. The well-preserved lenticular gypsum crystals are primary, as demonstrated by the presence of the original twinning and the absence of hydration textures or anhydrite relicts. Primary fluid inclusions of the lenticular gypsum crystals indicate a vadose environment of formation, with salinities between 1,800 and 14,000 ppm, pointing to a brackish but non-marine environment. Furthermore, gypsum exhibits ⁸⁷Sr/⁸⁶Sr values between 0.708034 and 0.708120, which are higher than those from marine evaporites of Campanian–Maastrichtian age, indicating a clear influence of fresh water. Gypsum δ ³⁴S _VCDT values (18.1 to 19.0 ± 0.5 ‰) and δ ¹⁸O_VSMOW values (11.0 to 15.2 ± 0.5 ‰), on the other hand, are typical isotopic values recorded in marine evaporites of this age. This apparent contradiction between fluid inclusion and Sr isotopic data is probably the result of some recycling from Upper Cretaceous evaporites. Based on all these observations, the sulphate-bearing layers are interpreted as probably formed in a near-coastal saline mudflat of a playa lake. As a whole, this study highlights the importance of combining different proxies when dealing with evaporites formed in brackish-water environments.     

Discovery of soft parts of a fossil brachiopod in the “Hunsrückschiefer” (Lower Devonian, Germany)

The author recently discovered among 16 discinid brachiopods from the Lower Devonian Hunsrück Slate, by using the X-ray technique, two specimens with mineralized soft parts and pedicle. These are truly unique finds, as previously no bodily preserved pedicle of fossil discinids has been described. Also, they prove that in the Hunsriick Slate soft parts can be pyritized. New shell observations give rise to doubts on the generic assignment ofOrbiculoidea mediorhenana Fuchs 1915. By comparing the anatomy of the related, livingLingula with the extinct discinid in question, a reconstruction of the latter is presented.     

Identification of Neandertal individuals in fragmentary fossil assemblages by means of tooth associations: The case of El Sidrón (Asturias,Spain)

Identification of the individuals represented in a fragmentary fossil assemblage is a key step in paleobiological research, as ensuing organism-level studies, as well as sampling strategies (e.g., DNA, isotopes, dating, etc.), may depend on the reliability of such estimates. In the human fossil record, dental remains represent the most abundant and informative material, allowing individual identification on the basis of a variety of diagnostic criteria. In this paper, we present a procedure for sequential association of the dental remains and the identification of the minimum number of individuals (MNI) represented in the 49,000-year-old Neandertal assemblage from El Sidrón (Asturias, Spain). In order to quantify the possible association errors, the 12 criteria used in this study are organised according to three levels of reliability. Following this procedure, a minimum of 13 individuals (seven adults, three adolescents, two juveniles and one infant) have been identified at El Sidrón, two of them uniquely represented by postcranial elements. A next step in this investigation foresees the development of methods for associating postcranial elements with the dentally-based identified individuals.     

Bone remodelling in Neanderthal mandibles from the El Sidrón site (Asturias, Spain)

Skull morphology results from the bone remodelling mechanism that underlies the specific bone growth dynamics. Histological study of the bone surface from Neanderthal mandible specimens of El Sidrón (Spain) provides information about the distribution of the remodelling fields (bone remodelling patterns or BRP) indicative of the bone growth directions. In comparison with other primate species, BRP shows that Neanderthal mandibles from the El Sidrón (Spain) sample present a specific BRP. The interpretation of this map allows inferences concerning the growth directions that explain specific morphological traits of the Neanderthal mandible, such as its quadrangular shape and the posterior location of the mental foramen.     

Squamate finding in “Lo Hueco” (Late Campanian-Early Maastrichtian, Cuenca Province, Spain): the second non-marine pythonomorph lizard

Two squamate vertebrae were discovered in the site of “Lo Hueco” (Cuenca, Spain; Late Campanian-Early Maastrichtian), which has yielded a rich and diversified fossil fauna. Their anatomical and microanatomical features are described. They reveal that these vertebrae probably belong to a new genus of Pythonomorpha. This taxon corresponds to the second non-marine pythonomorph lizard hitherto described. Anatomical, microanatomical and sedimentological data suggest a terrestrial or amphibious mode of life. This discovery raises questions about the evolutionary history of pythonomorph lizards in non-marine deposits.     

Seasonality and Paleoecology of the Late Cretaceous Multi-Taxa Vertebrate Assemblage of “Lo Hueco” (Central Eastern Spain)

Isotopic studies of multi-taxa terrestrial vertebrate assemblages allow determination of paleoclimatic and paleoecological aspects on account of the different information supplied by each taxon. The late Campanian-early Maastrichtian “Lo Hueco” Fossil-Lagerstätte (central eastern Spain), located at a subtropical paleolatitude of ~31°N, constitutes an ideal setting to carry out this task due to its abundant and diverse vertebrate assemblage. Local δ¹⁸O_PO4 values estimated from δ¹⁸O_PO4 values of theropods, sauropods, crocodyliforms, and turtles are close to δ¹⁸O_H2O values observed at modern subtropical latitudes. Theropod δ¹⁸O_H2O values are lower than those shown by crocodyliforms and turtles, indicating that terrestrial endothermic taxa record δ¹⁸O_H2O values throughout the year, whereas semiaquatic ectothermic taxa δ¹⁸O_H2O values represent local meteoric waters over a shorter time period when conditions are favorable for bioapatite synthesis (warm season). Temperatures calculated by combining theropod, crocodyliform, and turtle δ¹⁸O_H2O values and gar δ¹⁸O_PO4 have enabled us to estimate seasonal variability as the difference between mean annual temperature (MAT, yielded by theropods) and temperature of the warmest months (TWMs, provided by crocodyliforms and turtles). ΔTWMs-MAT value does not point to a significantly different seasonal thermal variability when compared to modern coastal subtropical meteorological stations and Late Cretaceous rudists from eastern Tethys. Bioapatite and bulk organic matter δ¹³C values point to a C₃ environment in the “Lo Hueco” area. The estimated fractionation between sauropod enamel and diet is ~15‰. While waiting for paleoecological information yielded by the ongoing morphological study of the “Lo Hueco” crocodyliforms, δ¹³C and δ¹⁸O_CO3 results point to incorporation of food items with brackish influence, but preferential ingestion of freshwater. “Lo Hueco” turtles showed the lowest δ¹³C and δ¹⁸O_CO3 values of the vertebrate assemblage, likely indicating a diet based on a mixture of aquatic and terrestrial C₃ vegetation and/or invertebrates and ingestion of freshwater.     

Examining the sarcosaprophagous fauna in a natural mountain environment (Sierra Espuña,Murcia, Spain)

The sarcosaprophagous community has been studied in a natural mountainous area at 400 m altitude, in Sierra Espuña (Murcia, SE Spain) during April and May 2007, using a modified Schoenly trap baited with a 5 kg piglet (Sus scrofa Linnaeus, 1758). In total, 13,527 specimens from 15 orders of arthropods were collected. A summary of the overall results is presented detailing the most relevant taxa. The relationship between colonizing fauna and the phase of decomposition of the carcass, which is a relevant aspect in determining the post mortem interval, has been also studied using PERMANOVA and SIMPER analysis. The importance of Diptera over other arthropods orders, and the fact that the entomosarcosaprophagous fauna configure a well-structured and progressively organized community, has been noted.     

New record of a sauropod in the Jurassic–Cretaceous transition of the Iberian Peninsular (Spain): palaeobiogeographical implications

In recent decades a unique association of basal neosauropod and turiasaur sauropods has been described from the Jurassic–Cretaceous transition of Spain. In this context, a sauropod femur from the Tithonian–Berriasian is studied for the first time. The femur in question is an isolated specimen, recovered from the Tera Group in Tera (Soria). It displays a unique mosaic of derived characters as yet undescribed in femora of the Upper Jurassic and Lower Cretaceous of Spain. A prominent lateral bulge, high eccentricity, and a lateromedially flattened proximal end link the femur from Tera with Titanosauriformes. Moreover, it presents a significant distal projection of the tibial condyle, a character observed in Asiatic Titanosauriformes of the Lower Cretaceous. The femur from Tera adds a fifth sauropod taxon to the Tithonian–Berriasian of Spain, and, for the first time, a representative of Titanosauriformes.     

The La Voulte-sur-Rhône Lagerstätte (Middle Jurassic,France)

The La Voulte Lagerstätte (Jurassic, France) is characterized by a diverse and exceptionally well-preserved fauna. It was located along the western Tethyan margin where the submarine relief was steep. The sedimentation was dominated by marls suggesting a low energy and deep-water depositional environment. The La Voulte biota is remarkable for its biodiversity with about 60 different species. The major components are the arthropods (50% of the species), the cephalopods (10%) and the echinoderms (10%). Among the arthropods, the composition and some anatomical features suggest a relatively deep-water environment characterized by dim-light conditions. The cephalopods and other organisms (pycnogonids, asterids), have extant analogues that all live in deep-water niches always exceeding 200 m. The fauna as a whole bears the characteristic features of the present-day bathyal fauna. The La Voulte Lagerstätte may be one of the rare Jurassic Lagerstätten, if not the unique, to have fossilized a deep marine fauna.     

What's in a beach? Soil micromorphology of sediments from the Lower Paleolithic site of 'Ubeidiya, Israel

A micromorphological study of archaeological sediments from the early Pleistocene site of 'Ubeidiya (Jordan Valley, Israel) was conducted to provide microenvironmental detail for the hominin occupation contexts and investigate site formation issues. Previous research shows that the hominin groups occupied the marshes and pebbly beaches at the shores of a lake during a regressive period, but given that some portions of the lithic and faunal assemblages are abraded and others fresh, there remains a question of whether the archaeological assemblages are in situ or reworked, and if reworked, by what mechanisms and from where. The rates of sedimentation within the regressive cycle, by which we can learn about the frequency and duration of exposed surfaces amenable for hominin occupation is also unknown. Finally, the artificial nature of some of the pebbly layers has been questioned. The micromorphological analysis yielded the identification of twelve microfacies; the majority of these represent fluvially derived floodplain soils or distal mudflow deposits, and a minor number are sediments of lacustrine origin: mudflats and shallow subaqueous sediments. These represent the natural habitats of the 'Ubeidiya hominins and might serve as a reference to similar contexts of other early hominin sites. The sedimentary model proposed here entails the rapid deposition of fluvially derived low-energy sediments at and around the shoreline, followed by prolonged periods of exposure, during which surfaces stabilized within a relatively wet, marshy environment. This interpretation suggests that the abraded portions of the archaeological assemblages are a result of prolonged surface exposure rather than high-energy transport from a distant source or to wave reworking at the shoreline, and supports the consideration of these assemblages as archaeological palimpsests, with locally reworked fresh and abraded elements. No micromorphological evidence supporting anthropogenic agency in the formation of the pebbly layers was found. The entire regressive cycle entailed unvarying climatic conditions with seasonal fluctuations and episodic lacustrine incursions, and with a trend towards arid conditions in the end.     

Modern and fossil diatom assemblages from Bol’shoy Lyakhovsky Island (New Siberian Archipelago,Arctic Siberia)

This article discusses the results of a taxonomic and ecological investigation of diatoms from polygonal ponds and Quaternary permafrost deposits of Bol’shoy Lyakhovsky Island (New Siberian Archipelago) and the reconstruction of climatic changes on the Island during late Pleistocene/Holocene transition using fossil diatom assemblages from the permafrost deposits. The taxonomic list of diatoms includes 159 diatom species. The main ecological factors that determine the distribution of diatoms in the investigated data set are mean July air temperature, рН, electrical conductivity, water depth, and concentrations of Si⁴⁺ and Al³⁺. An increase in water depth and stable lacustrine conditions in the Lateglacial–Holocene in the ancient thermokarst lake relate to Lateglacial warming before 11860 ± 160 years BP and during the early Holocene between 11210 ± 160 and 7095 ± 60 years BP.     

Late Holocene environmental changes inferred from diatom,chironomid, and pollen assemblages in an Andean lake in Central Chile,Lake Laja (36°S)

A sediment core encompassing the last 2000 years was extracted from Lake Laja, Chile, (36°54′S, 71°05′W) using an Uwitec drilling platform. The sediment was subsampled for loss on ignition, nutrients, biogenic silica, and biological proxies (diatoms, chironomids, pollen). The sedimentary profile was characterized by several coarse volcanic layers. Loss on ignition, nutrients, and biogenic silica showed an increasing trend that suggests a recent shift to a higher trophic status. Diatom assemblages also suggested higher nutrient content with increased abundances of Aulacoseira granulata, A. distans, and Asterionella formosa. At the same time, a marked change in the benthic and facultative planktonic taxa may be associated with cooling. This period of change coincides with the European Little Ice Age (LIA). The chironomid profile showed four key zones distinguished largely by changes in the abundance of Tanytarsini, Parachironomus, and Macropelopia. Like diatoms, chironomids also seemed to reflect a shift to higher trophic conditions in the upper part reflected by increasing abundance of taxa such as Tribelos/Phaenopsectra, Cricotopus/Orthocladius, and Ablabesmyia. The most striking feature in the chironomid assemblage is the abundance of Podonominae, Parapsectrocladius, and Limnophyes/Compterosmittia, which could be associated with a cold-dry period between 1500 and 1900 AD in Lake Laja (the period of the European LIA). Pollen assemblages indicated fluctuations in humidity through changes in Nothofagus dombeyi-type, Poaceae, and Ephedra, and we inferred a strong human impact over the last 100 years from the appearance of Plantago and increased levels of Poaceae and Asteraceae subf. Cichorioidae. Finally, the three proxies showed the occurrence of a cold-dry event in Lake Laja (~1550–1900 AD), which roughly coincides with the European LIA. However the data from this research, does not prove neither rejects the existence of the occurrence of the MWP in the central Andes.     

A new Microphorites in the Lower Cretaceous amber of the Southwest of France (Diptera: Dolichopodidae, “Microphorinae”)

A new deposit of Lower Cretaceous amber, found in Charente-Maritime (SW France) has yielded an important entomofauna with numerous arthropod associations characteristic of moist ground. We describe a new species of Dolichopodidae: ‘Microphorinae’(Diptera: Empidoidea), Microphorites deploegi n. sp. on the basis of seven male and female specimens of exceptional state of preservation. This genus was previously only known from Lebanese amber of the Lower Cretaceous. The present discovery supports a reconstruction of the palaeoenvironment as a sandy beach along the sea, under a warm climate.     

Beyond nature: The management of a productive cultural landscape in Las Médulas area (El Bierzo,León,Spain) during pre-Roman and Roman times

Abstract

This article focuses on the analysis of plant remains (seeds/fruits, charcoal, pollen, spores, and non-pollen palynomorphs) from two archaeological sites (pre-Roman and Roman) located in Las Médulas, a cultural landscape, in the northwestern part of the Iberian Peninsula. The article explores the way the communities living in the area managed their environment and the impact of productive activities on the landscape. This research has shown the multiplicity of needs this landscape satisfied and the various ways these communities managed the surrounding environment through different productive activities (agriculture, animal husbandry, and mining amongst others).