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result(s) for
"Delclòs, Xavier"
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Arthropods in modern resins reveal if amber accurately recorded forest arthropod communities
2018
Amber is an organic multicompound derivative from the polymerization of resin of diverse higher plants. Compared with other modes of fossil preservation, amber records the anatomy of and ecological interactions between ancient soft-bodied organisms with exceptional fidelity. However, it is currently suggested that ambers do not accurately record the composition of arthropod forest paleocommunities, due to crucial taphonomic biases. We evaluated the effects of taphonomic processes on arthropod entrapment by resin from the plant Hymenaea, one of the most important resin-producing trees and a producer of tropical Cenozoic ambers and Anthropocene (or subfossil) resins. We statistically compared natural entrapment by Hymenaea verrucosa tree resin with the ensemble of arthropods trapped by standardized entomological traps around the same tree species. Our results demonstrate that assemblages in resin are more similar to those from sticky traps than from malaise traps, providing an accurate representation of the arthropod fauna living in or near the resiniferous tree, but not of entire arthropod forest communities. Particularly, arthropod groups such as Lepidoptera, Collembola, and some Diptera are underrepresented in resins. However, resin assemblages differed slightly from sticky traps, perhaps because chemical compounds in the resins attract or repel specific insect groups. Ground-dwelling or flying arthropods that use the treetrunk habitat for feeding or reproduction are also well represented in the resin assemblages, implying that fossil inclusions in amber can reveal fundamental information about biology of the past. These biases have implications for the paleoecological interpretation of the fossil record, principally of Cenozoic amber with angiosperm origin.
Journal Article
A 10 m resolution urban green space map for major Latin American cities from Sentinel-2 remote sensing images and OpenStreetMap
2022
Mapping is fundamental to studies on urban green space (UGS). Despite a growing archive of land cover maps (where UGS is included) at global and regional scales, mapping efforts dedicated to UGS are still limited. As UGS is often a part of the heterogenous urban landscape, low-resolution land cover maps from remote sensing images tend to confuse UGS with other land covers. Here we produced the first 10 m resolution UGS map for the main urban clusters across 371 major Latin American cities as of 2017. Our approach applied a supervised classification of Sentinel-2 satellite images and UGS samples derived from OpenStreetMap (OSM). The overall accuracy of this UGS map in 11 randomly selected cities was 0.87. We further improved mapping quality through a visual inspection and additional quality control of the samples. The resulting UGS map enables studies to measure area, spatial configuration, and human exposures to UGS, facilitating studies on the relationship between UGS and human exposures to environmental hazards, public health outcomes, urban ecology, and urban planning.Measurement(s)urban green spaceTechnology Type(s)remote sensing • volunteered geographic information • supervised machine learningSample Characteristic - EnvironmentcitySample Characteristic - LocationArgentina • Brazil • Chile • Colombia • Costa Rica • El Salvador • Guatemala • Mexico • Nicaragua • Panama • Peru
Journal Article
Unravelling the mystery of “Madagascar copal”: Age, origin and preservation of a Recent resin
by
Peñalver, Enrique
,
Delclòs, Xavier
,
Ranaivosoa, Voajanahary
in
Amber
,
Amber - chemistry
,
Amber - history
2020
The loss of biodiversity during the Anthropocene is a constant topic of discussion, especially in the top biodiversity hotspots, such as Madagascar. In this regard, the study of preserved organisms through time, like those included in \"Madagascar copal\", is of relevance. \"Madagascar copal\" originated from the leguminous tree Hymenaea verrucosa, which produced and produces resin abundantly. In the last 20 years, interest has focused on the scientific study of its biological inclusions, mainly arthropods, described in dozens of publications. The age and origin of the deposits of \"Madagascar copal\" have not yet been resolved. Our objectives are to determine its age and geographical origin, and thus increase its scientific value as a source of biological/palaeobiological information. Although Hymenaea was established in Madagascar during the Miocene, we did not find geological deposits of copal or amber in the island. It is plausible that the evolution of those deposits was negatively conditioned by the type of soil, by the climate, and by the development of soil/litter microorganisms, which inhibit preservation of the resin pieces in the litter and subsoil over 300 years. Our results indicate that \"Madagascar copal\" is a Recent resin, up to a few hundred years old, that originated from Hymenaea trees growing in the lowland coastal forests, one of the most endangered ecosystems in the world. The included and preserved biota is representative of that ecosystem today and during historical times. Inclusions in this Recent resin do not have the palaeontological significance that has been mistakenly attributed to them, but they do have relevant implications for studies regarding Anthropocene biodiversity loss in this hottest hotspot.
Journal Article
Early evolution and ecology of camouflage in insects
by
Wierzchos, Jacek
,
Engel, Michael S.
,
Pérez-de la Fuente, Ricardo
in
Adaptation, Physiological
,
Amber
,
Animal behavior
2012
Taxa within diverse lineages select and transport exogenous materials for the purposes of camouflage. This adaptive behavior also occurs in insects, most famously in green lacewing larvae who nestle the trash among setigerous cuticular processes, known as trash-carrying, rendering them nearly undetectable to predators and prey, as well as forming a defensive shield. We report an exceptional discovery of a green lacewing larva in Early Cretaceous amber from Spain with specialized cuticular processes forming a dorsal basket that carry a dense trash packet. The trash packet is composed of trichomes of gleicheniacean ferns, which highlight the presence of wildfires in this early forest ecosystem. This discovery provides direct evidence of an early acquisition of a sophisticated behavioral suite in stasis for over 110 million years and an ancient plant–insect interaction.
Journal Article
Ancient amino acids from fossil feathers in amber
2019
Ancient protein analysis is a rapidly developing field of research. Proteins ranging in age from the Quaternary to Jurassic are being used to answer questions about phylogeny, evolution, and extinction. However, these analyses are sometimes contentious, and focus primarily on large vertebrates in sedimentary fossilisation environments; there are few studies of protein preservation in fossils in amber. Here we show exceptionally slow racemisation rates during thermal degradation experiments of resin enclosed feathers, relative to previous thermal degradation experiments of ostrich eggshell, coral skeleton, and limpet shell. We also recover amino acids from two specimens of fossil feathers in amber. The amino acid compositions are broadly similar to those of degraded feathers, but concentrations are very low, suggesting that much of the original protein has been degraded and lost. High levels of racemisation in more apolar, slowly racemising amino acids suggest that some of the amino acids were ancient and therefore original. Our findings indicate that the unique fossilisation environment inside amber shows potential for the recovery of ancient amino acids and proteins.
Journal Article
The Early Cretaceous coastal lake Konservat-Lagerstätte of La Pedrera de Meià (Southern Pyrenees)
2023
A state of the art of the Barremian Konservat-Lagerstätte of la Pedrera de Meià site (Southern Pyrenees) is compiled here including the acquisition of new geological data. The relevance of this site, together with the nearby la Cabroa site, is due to its paleobiotic richness and the fact that 113 holotypes and paratypes of flora and fauna have already been defined. Since its discovery at the end of the 19th century and its exploitation as a lithographic limestone quarry, the site has been the object of paleontological interest by national and foreign research teams that are summarized here (including the catalogue of 224 publications). A survey of the existing type specimens in collections all over Europe is also provided, being France and Germany, the countries where more fossils are hosted other than Spain. The geological frame of this site is also reviewed, by revisiting unpublished geological mappings (mainly that of Krusat, 1966) and integrating it in a comprehensive map that includes 4 revisited outcrops of lithographic limestone which could be potential paleontological sites. Previous stratigraphic sections did allow the precise framing of paleontological data and findings, that now can be allocated in new stratigraphic sections accounting for 50m and that contain a minimum of 40.000 laminae, being a minimum estimation of the years represented in the la Pedrera de Meià site.
Journal Article
Necrophagy by insects in Oculudentavis and other lizard body fossils preserved in Cretaceous amber
by
Peñalver, Enrique
,
Peretti, Adolf M.
,
Solórzano‑Kraemer, Mónica M.
in
631/158
,
631/158/670
,
631/158/856
2023
When a vertebrate carcass begins its decay in terrestrial environments, a succession of different necrophagous arthropod species, mainly insects, are attracted. Trophic aspects of the Mesozoic environments are of great comparative interest, to understand similarities and differences with extant counterparts. Here, we comprehensively study several exceptional Cretaceous amber pieces, in order to determine the early necrophagy by insects (flies in our case) on lizard specimens, ca. 99 Ma old. To obtain well-supported palaeoecological data from our amber assemblages, special attention has been paid in the analysis of the taphonomy, succession (stratigraphy), and content of the different amber layers, originally resin flows. In this respect, we revisited the concept of syninclusion, establishing two categories to make the palaeoecological inferences more accurate: eusyninclusions and parasyninclusions. We observe that resin acted as a “necrophagous trap”. The lack of dipteran larvae and the presence of phorid flies indicates decay was in an early stage when the process was recorded. Similar patterns to those in our Cretaceous cases have been observed in Miocene ambers and actualistic experiments using sticky traps, which also act as “necrophagous traps”; for example, we observed that flies were indicative of the early necrophagous stage, but also ants. In contrast, the absence of ants in our Late Cretaceous cases confirms the rareness of ants during the Cretaceous and suggests that early ants lacked this trophic strategy, possibly related to their sociability and recruitment foraging strategies, which developed later in the dimensions we know them today. This situation potentially made necrophagy by insects less efficient in the Mesozoic.
Journal Article
Mating and aggregative behaviors among basal hexapods in the Early Cretaceous
2018
Among the many challenges in paleobiology is the inference and reconstruction of behaviors that rarely, if ever, leave a physical trace on the environment that is suitable for fossilization. Of particular significance are those behaviors tied to mating and courtship, individual interactions critical for species integrity and continuance, as well as those for dispersal, permitting the taxon to expand its distribution as well as access new habitats in the face of local or long-term environmental change. In this context, two recently discovered fossils from the Early Cretaceous amber of Spain (ca. 105 mya) give a detailed view of otherwise fleeting ethologies in Collembola. These occurrences are phylogenetically spaced across the class, and from species representing the two major clades of springtailsÐSymphypleona and Entomobryomorpha. Specifically, we report unique evidence from a symphypleonan male (Pseudosminthurides stoechus SaÂnchez-GarcõÂa & Engel, 2016) with modified antennae that may have functioned as a clasping organ for securing females during mating on water's surface, and from an aggregation of entomobryomorphan individuals (Proisotoma communis Sánchez-García & Engel, 2016) purportedly representing a swarming episode on the forest floor. We demonstrate that the mating behavioral repertoire in P. stoechus, which is associated with considerable morphological adaptations, likely implied elaborate courtship and maneuvering for guarantee sperm transfer in an epineustic species. These discoveries reveal significant behaviors consistent with modern counterparts and a generalized stasis for some ancient hexapod ethologies associated with complex mating and courtship and social or pre-social aggregations, so critical to specific constancy and dispersal.
Journal Article
parasitised feathered dinosaurs as revealed by Cretaceous amber assemblages
by
Grimaldi, David A
,
Pérez-de la Fuente, Ricardo
,
Peñalver, Enrique
in
Amber
,
Animals
,
Dinosaurs - anatomy & histology
2017
Ticks are currently among the most prevalent blood-feeding ectoparasites, but their feeding habits and hosts in deep time have long remained speculative. Here, we report direct and indirect evidence in 99 million-year-old Cretaceous amber showing that hard ticks and ticks of the extinct new family Deinocrotonidae fed on blood from feathered dinosaurs, non-avialan or avialan excluding crown-group birds. A †Cornupalpatum burmanicum hard tick is entangled in a pennaceous feather. Two deinocrotonids described as †Deinocroton draculi gen. et sp. nov. have specialised setae from dermestid beetle larvae (hastisetae) attached to their bodies, likely indicating cohabitation in a feathered dinosaur nest. A third conspecific specimen is blood-engorged, its anatomical features suggesting that deinocrotonids fed rapidly to engorgement and had multiple gonotrophic cycles. These findings provide insight into early tick evolution and ecology, and shed light on poorly known arthropod-vertebrate interactions and potential disease transmission during the Mesozoic.
Journal Article
Mobility Patterns and Spatial Behavior of Cruise Passengers Visiting Barcelona
2025
Cruise ship tourism in port cities, while offering opportunities, has brought its own challenges, including overcrowding, disruption to local community mobility, and growing resident concerns, which recently escalated to anti-tourism activities. This article aims to understand the mobility patterns, transportation preferences, and spatial behaviors of cruise ship passengers within the City of Barcelona (Spain). The study is based on a survey conducted with cruise ship tourists visiting the city (n = 793). The key findings reveal the concentration of tourist activity in the old part of the city, and the similarity in spatial behaviors within the city, while the primary mode of exploration is walking, supported by motorized modes of transfer to access distant attractions. Socio-demographic factors and visit characteristics, such as age, group composition, and expenditure levels, are associated with mobility and spatial behavior. This article adds new evidence on the mobility patterns and spatial behaviors of cruise ship tourists visiting a major tourist city. With better knowledge of where cruise ship passengers concentrate, what activity patterns they show, and their preferred modes of transport, policymakers can manage more effectively the influx during peak times and in high-density areas. Strategies to distribute visitors more evenly across the city could be devised to alleviate pressure on heavily frequented zones.
Journal Article