Angela Delgado Buscalioni

Universidad Autónoma de Madrid | UAM · Department of Biology

Las Hoyas (Cuenca, Spain) represents a unique Lower Cretaceous (Barremian) fossil biota of a wetland. The site has yielded a particularly diverse assemblage of more than twenty thousand plant and animal fossils, many of which present unprecedented soft-tissue preservation, including microstructural details. Among the most significant discoveries ar...

A quantitative approach to plant taphonomy focusing on preservation type and fragment size is tested by comparing 3338 Weichselia reticulata fragments from 25 Lower Cretaceous localities of different ages and deposi-tional environments. Moreover, palaeobiological insights are also obtained from the taphonomic analyses. In the case of the specimens...

The Early Cretaceous (129-125 Mya) Las Hoyas wetland in Cuenca (Spain) contains the richest Cretaceous avifauna in the European continent. More than 30 years of paleontological excavations at this site have resulted in the discovery of many relevant enantiornithine fossils. Among these, Iberomesornis romerali, Concornis lacustris, Eoalulavis hoyasi...

We describe a trackway (LH-Mg-10-16) occurring in laminated carbonated limestones of the Las Hoyas locality, Serranía de Cuenca, Spain. It is unmistakably a large theropod dinosaur trackway encompassing two unusual aspects, namely, wide-steps, and a set of equally deformed left footprints (with a dislocated digit). The layer also preserves other ve...

The bone histology of non-avian theropods such as Troodon, early pygostylians such as Confuciusornis, and neornithines, is characterized by the post-hatching formation of fibrolamellar complex. In contrast, the cortex of enantiornithine birds, like Concornis and Iberomesornis, is made of poorly vascularized parallel-fibred tissue. The cortex of met...

Cuenca, a small city with a rich historical and palaeontological heritage, is the ideal location to explore how the scientific knowledge of its inhabitants has changed over the years. In 2010 and 2019, two surveys were conducted on the streets of Cuenca to characterise their scientific profiles and how they perceive heritage outreach initiatives in...

Cladophlebis is a very variable form genus of Mesozoic fern foliage. At the Spanish Konservat Lagerstätte of Las Hoyas (Upper Barremian), several pinnae that could be assigned to this genus have been unearthed. The identification of different species is complicated due to the high morphological disparity of the sample. Therefore, a quantitative and...

Experimental taphonomy using microbial mats offers new insights into the mechanisms involved in the decay of organisms and their preservation as fossils. In this paper, the experimental decay products of soft-bodied insect larvae (the greater wax moth, Galleria mellonella, and the mealworm, Tenebrio molitor) in microbial mats have been described an...

The exceptional fossil site of Las Hoyas (upper Barremian, Cuenca, Spain) yields abundant small to medium vertebrate coprolites, hindering the search for parasites. We studied the contents of 29 coprolites that were previously classified into distinct morphotypes. Several parasitic eggs were retrieved from two of these coprolites, confirming the se...

Las Hoyas, a locality of the La Huérguina Formation in the southwestern Iberia Basin (Cuenca province, Spain), is a well-known late Barremian Konservat-Lagerstätte highly rich in coprolites that have a wide variety of morphologies. Thin sections of twenty specimens were prepared from seven coprolite morphotypes. All of the examined coprolites exhib...

Background The neosuchian crocodyliform genus Hulkepholis constitutes the longirostral lineage of the European Goniopholididae. It comprises two species ranging from the Valanginian of southern England to the lower Albian of the northern Teruel (Spain). A new species of Hulkepholis is described based on a partially complete skull from the lower Bar...

The architecture of primary and secondary pinnae of the fossil fern Weichselia reticulata (C. Stokes et Webb) Fontaine is studied based on 28 large specimens from the upper Barremian La Huérguina Formation of the fossil locality Las Hoyas, Cuenca, Spain. The study of the specimens is performed through a morphometric analysis consisting in a reformu...

Two isolated theropod teeth from Las Hoyas are described. Current evidence suggests their identification as a carcharodontosaurid akin to Concavenator and a putative spinosaurid based on data from morphology and morphometry. These findings might represent the second carcharodontosaurid and the first Spinosauridae from La Huérguina Fm.

Laser-Stimulated Fluorescence (LSF) is used to identify fully fledged feathering in the hatchling enantiornithine bird specimen MPCM-LH-26189, supporting precocial nesting behavior in this extinct group. The LSF results include the detection of a long pennaceous wing feather as well as cover feathers around the body. The LSF technique showed improv...

The exceptional preservation of the Las Hoyas coprolites allows the taphonomic study of inclusions on twelve morphotypes and twenty-three specimens. Non-destructive techniques were applied to study the digestion features (pitting, corrosion lines, shape of the fractures at the ends) and the arrangement, number, and size of inclusions. An analysis b...

The sequence of decay in fern pinnules was tracked using the species Davallia canariensis. Taphonomic alterations in the sediment–water interface (control tanks) and in subaqueous conditions with microbial mats were compared. The decay sequences were similar in control and mat tanks; in both cases, pinnules preserved the shape throughout the four-m...

Eighty-three publications have been examined to recover information on the palaeogeography, the chronostratigraphy and the presence of the fossil fern genus Weichselia Stiehler in different depositional environments. This fossil fern foliage was reported in 72 localities worldwide. Its fossil record ranges from the Bathonian to the Cenomanian, pred...

La excavación sistemática capa a capa que se lleva a cabo del yacimiento de Las Hoyas (Barremiense superior de Cuenca, España) permite el estudio de asociaciones fósiles en conjunción con datos sedimentarios. Nuestros resultados muestran que las especies de helechos encontradas en Las Hoyas formaron dos asociaciones vegetales separadas, una con dom...

The paleontological heritage of the fossil site of Las Hoyas (Early Cretaceous of Cuenca, Spain) is becoming a relevant part of the sociocultural identity of Castilla-La Mancha autonomous community in general, and of Cuenca province in particular. The most recent scientific advances, including several fossil findings that have had high scientific i...

Coprolites are some of the most abundant fossils at the Las Hoyas site, a well-known Early Cretaceous Konservat-Lagerstätte located in Cuenca, central Spain. The coprolite association is described, introducing taphonomic features and sedimentological properties. This study is based on a subsample of 433 fossils selected from some 2000 specimens col...

Coprolites morphotype features presented as a synthetic comparison of the corresponding description, with an appreciation of analogous coprolite shapes based on [64]. (PDF)

List of the 433 specimens studied, with their corresponding morphotype. (PDF)

Several localities situated at Buenache de la Sierra have yielded micro and macrofossils remains from plants, invertebrates and vertebrates. The Barranco la Pata la Mona fossil site provided axial and appendicular bones attributed to the genus Iguanodon. Here we present additional remains that include a femur, a scapula and both pubes. All remains...

Para que el patrimonio paleontológico se convierta en un recurso y tenga una dimensión cultural requiere de personal con dedicación permanente en los museos. Estos técnicos especializados son los intermediarios adecuados para atender las notificaciones de los hallazgos de ciudadanos y coordinar con los especialistas aquellos aspectos relativos a la...

A detailed study of the floral and faunal diversity of an upper Barremian lentic ecosystem was performed by examining 50,000 microfossils. The study provides an assemblage of 41 species of charophytes, spermatophytes, ostracods, molluscs, and vertebrates (including eggshells). The main goal of this study is to reconstruct the palaeoecology of a flu...

The tree fern Weichselia reticulata (Stokes et Webb) Fontaine had a wide palaeogeographic distribution in Laurasia and Gondwana during the Jurassic and Cretaceous periods. In particular, leaf fragments of a few centimetres are very abundant from the upper Barremian of Las Hoyas (Cuenca, Spain) and the Barremian of Beare Green Pit (Surrey, England)....

The anatomy and phylogenetic relationships of the Las Hoyas gobiosuchid (upper Barremian, La Huérguina Formation, Cuenca, Spain) are discussed on the basis of two fully articulated specimens. Phylogenetic analysis supports the monophyly of Gobiosuchidae, defined by the Las Hoyas taxon, Cassissuchus sanziuami, gen. et sp. nov., as the sister taxon o...

The pattern and sequence of the decomposition of the Pipidae African dwarf frog (Hymenochirus boettgeri) is tracked in an experiment with microbial mats in order to explore soft tissue preservation over three years. Frog decay in microbial mats is preceded by rapid entombment (25–30 days) and mediated by the formation of a sarcophagus, which is bui...

Synthesis volume in the study of Las Hoyas palaeontological locality (upper Barremian) from Spain. It incorporates many researchers who have largerly contributed to the understanding of the geology, palaeobiology taphonomy and palaeoecology of the locality.

El yacimiento paleontológico de Las Hoyas (Cuenca) ha ocupado reiteradamente un espacio en los medios autonómicos, nacionales e internacionales en los últimos años. Los descubrimientos y publicaciones científicas más recientes han hecho que la sociedad castellano-manchega redescubra su interés por la Paleontología. El acuerdo del 15 de marzo de 201...

The Las Hoyas Lagerstätte in Spain contains the oldest known fossils of aquatic oligochaete worms. These exceptionally well preserved worms indicate a highly diversified association of worms composed of several members of the family Tubificidae, putative species of the terrestrial Enchytraei-dae, and probably the roundworm nematode Mermithidae. Thi...

Microbial mats have been hypothesized to improve the persistence and the preservation of organic remains during fossilization processes. We test this hypothesis with long-term experiments (up to 5.5 years) using invertebrate and vertebrate corpses. Once placed on mats, the microbial community coats the corpses and forms a three-dimensional sarcopha...

The Konservat-Lagerstätte of Las Hoyas, from the Barremian of Cuenca, in central Spain, has provided a large amount of data whose integration reveals the uniqueness of this locality. Evidence provided by sedimentology, taphonomy, and paleobiology indicates that the paleoenvironment of Las Hoyas corresponds to that of a freshwater carbonatic lentic...

The Konservat-Lagerstätte of Las Hoyas, from the Barremian of Cuenca, in central Spain, has provided a large amount of data whose integration reveals the uniqueness of this locality. Evidence provided by sedimentology, taphonomy, and paleobiology indicates that the paleoenvironment of Las Hoyas corresponds to that of a freshwater carbonatic lentic...

This study provides experimental evidence confirming the significance of microbial mat presence in controlling the spatial and temporal development of chemical microenvironments which become established inside and outside decaying fish carcasses. Dissolved oxygen (DO) and pH profiles were monitored over 1,000 days with microelectrodes positioned in...

The Mesozoic era (252–66 million years ago), known as the domain of dinosaurs, witnessed a remarkable ecomorphological diversity of early mammals. The key mammalian characteristics originated during this period and were prerequisite for their evolutionary success after extinction of the non-avian dinosaurs 66 million years ago. Many ecomorphotypes...

The Mesozoic era (252–66 million years ago), known as the domain of dinosaurs, witnessed a remarkable ecomorphological diversity of early mammals. The key mammalian characteristics originated during this period and were prerequisite for their evolutionary success after extinction of the non-avian dinosaurs 66 million years ago. Many ecomorphotypes...

Despite a wealth of fossils of Mesozoic birds revealing evidence of plumage and other soft-tissue structures, the epidermal and dermal anatomy of their wing's patagia remain largely unknown. We describe a distal forelimb of an enantiornithine bird from the Lower Cretaceous limestones of Las Hoyas, Spain, which reveals the overall morphology of the...

Microbial mats have been repeatedly suggested to promote early fossilization of macroorganisms. Yet, experimental simulations of this process remain scarce. Here, we report results of 5 year-long experiments performed onfish carcasses to document the influence of microbial mats on mineral precipitation during early fossilization. Carcasses were ini...

Although the implication of microbial mats has been for long time accepted in order to explain exceptional preservation of fossils, there was an important lack of experimental evidences. In this framework, taphonomic experiments are capital to reproduce and explain early fossilization. Our previous research (Iniesto et al., 2013) have pointed out t...

The vertebrate-bearing beds of the Laño quarry (Condado de Treviño) are among the most relevant sites from the Late Cretaceous of Europe. Geologically, Laño and the adjacent region are set on the southern limb of the South-Cantabrian Synclinorium (SE Basque-Cantabrian Region, northern Iberian Peninsula). The Laño sites were discovered in 1984; thou...

Avian evolution has captured the attention of researchers over centuries, with the origin of flight as one of the main focus of interest. The development of different flight styles is a milestone for the radiation of avians, and skeletal adaptations to such end should therefore help to understand the ecological diversity of birds. In spite of ex...

This study aims to interpret the axial patterning of the crocodylian neck, and to find a potential taxonomic signal that corresponds to vertebral position. Morphological variation in the cervico-thoracic vertebrae is compared in fifteen different crocodylian species using 3D geometric morphometric methods. Multivariate analysis indicated that the p...

Fossil remains of spelaeogriphaceans (Family Acadiocarididae) are common in Las Hoyas Konservat-Lagerstätte (upper Barremian, La Huérguina Formation, southwestern Iberian Basin), although they belong to an extremely rare group in the fossil record. They have been interpreted as having inhabited karstic environments as do their contemporaneous equiv...

The slender-snouted Campanian through Ypresian “thoracosaurs” are currently viewed as early relatives of the living Indian gharial (Gavialis gangeticus), which is the focus of an unresolved phylogenetic conflict between morphological and molecular data sets. However, substantial stratigraphic and morphological gaps exist within thoracosaurs and bet...

El proceso de formación de fósiles excepcionales guarda, con frecuencia, relación con la presencia simultánea de tapetes microbianos (Seilacher et al., 1985). La probable participación de los microorganismos integrantes de los tapetes parece clave en muchos procesos tafonómicos esenciales como protección, retraso en la descomposición, formación de...

We explored the morphological organization of the skull within Crocodylidae analyzing functional and phylogenetic interactions between its two constituent functional modules: the rostrum and the postrostrum. We used geometric morphometrics to identify localized shape changes, focusing on the differences between the major clades of the crown-group C...

X-ray diffraction, optical polarizing microscopy, scanning electron microscopy and electron microprobeto, have been used to analyse the diagenetic processes of isolated dinosaur bones and ribs attributed to an ornithopod dinosaur from Buenache de la Sierra (Upper Barremian, La Huérguina Formation). We also examine the geochemical and mineralogical...