Anatomical differentiation of isolated scales of amiiform fishes (Amiiformes, Actinopterygii) from the Early Cretaceous of Las Hoyas (Cuenca, Spain)

Les écailles des poissons amiiformes sont plus différentes les unes des autres que ce qu’on avait précédemment affirmé. L’anatomie des écailles des trois taxons d’amiiformes du Crétacé inférieur (Barrémien) de Las Hoyas (Cuenca, Espagne) est décrite en détail. Les différences observées permettent la répartition des écailles isolées de cette localité entre ces trois taxons, ce qui permet de disposer d’un échantillonnage assez large, autorisant des études paléobiologiques et paléoécologiques.The scales of amiiform fishes are more different from each other than previously stated. The anatomy of the scales of the three amiiform taxa from the Early Cretaceous (Barremian) of Las Hoyas (Cuenca, Spain) is described in detail. The differences between them has allowed the segregation of isolated scales form the fossil record of this site into the three taxa, providing relatively large population samples that can be studied from a palaeobiological and palaeoecological point of view

A new genus and species for the amiiform fishes previously assigned to Amiopsis from the Early Cretaceous of Las Hoyas, Cuenca, Spain

The Mesozoic actinopterygian fish Amiopsis has been reported from three different localities in the Iberian Peninsula. Amiopsis woodwardi was described from the Berriasian–Valanginian of El Montsec (Lérida, Spain). Isolated vertebral centra referred to Amiopsis were found in the Barremian of Buenache de la Sierra (Cuenca, Spain). Finally, amiiform material from the Barremian of Las Hoyas (Cuenca, Spain) were reported as Amiopsis cf. A. woodwardi, due to the overall similarity with the species from El Montsec. Here a detailed anatomical description of the material from Las Hoyas is provided for the first time. The unique combination of characters seen in this taxon, some of which are not shared with Amiopsis but with more derived amiids, indicates that it represents a new taxon, which is here named Hispanamia newbreyi gen. nov., sp. nov

History of two lineages: Comparative analysis of the fossil record in Amiiformes and Pycnodontiformes (Osteischtyes, Actinopterygii)

Amiiformes and pycnodontiformes are two orders of neopterygian fishes that were broadly distributed, and frequently appeared together, during the Mesozoic. Comparison of their fossil record reveals both common traits and significant differences. They both appeared in the Western Tethys and reached maximum diversity during the Cretaceous. The differences in their evolutionary history involve dissimilar patterns of diversity and disparity; pycnodonts are more diversified taxonomically and present larger ecomorphological disparity. This implies that they used different strategies to compete with teleosts, which were unable to displace them from their specialized niches for more than 100 ka. The reasons why this did not happen sooner are difficult to approach, and may include radical environmental changes (i.e., marine transgressions, opening of the Atlantic, closing of the Tethys and opening of the Mediterranean). It is nonetheless clear that the evolutionary novelties of the Teleostei per se were not enough to grant them advantage in the competition for the ichthyofagous and durophagous niches at least during the Late Triassic, the whole Jurassic and the Early Cretaceou

Paleobiología de los peces amiiformes del Cretácico Inferior de Las Hoyas: Una aproximación multidisciplinar integradora

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología. Fecha de lectura: 12-06-2015The fossil record of the Early Cretaceous (Barremian) of Las Hoyas includes three taxa of amiiform fishes. These taxa, traditionally assigned to the species Caturus tarraconensis, Amiopsis woodwardi and Vidalamia catalunica, represent actually three new species. These species are the basis for a multidisciplinary study whose objective is to comprehend the palaeobiology of these fishes in the context of a wetland ecosystem. From a phylogenetic point of view, one of the species represents a primitive lineage, with a mosaic combination of characters from both caturoids and amioids. The second species is classified as plesion Vidalamiinae, and the third one as a member of this same subfamily. A palaeobiogeographic study of the order Amiiformes, including the three species from Las Hoyas, shows that the record of this group extends from at least the Early Jurassic to Recent times, reaching its maximum diversity during the Cretaceous. Its historical distribution is mainly explained by a series of vicariant events that originated from the Tethys Sea. The osseochronometric analysis of the growth cessation marks detected in the scales of the three species shows that they presented different growth profiles. Growth of amiiform fishes seems to have a phylogenetic component, and to be strongly influenced by environmental conditions, especially temperature. Actuotaphonomical experimentation of decay in extant fish carcasses confirms that a freshwater environment favors a severe degradation of tissues. In consequence, the presence of a protection mechanism, such as microbial mats, is needed to justify the exceptional preservation of the fossil record from Las Hoyas. Additionally, this experimentation shows that carcasses suffer abrasion by transport even in very low energy systems. Absence of evidence of abrasion in the amiiform fossil fishes of Las Hoyas suggests that their association at this site is autochthonous in origin. The autochthony of the association allows to interpret the sample of each of the three species as representative of their original populations. An analysis of the population structure of these species shows that they presented habitat partitioning: juvenile and adult individuals did not inhabit the same environment. The ecological role played by the three species in the palaeowetland of Las Hoyas would be different both ontogenetically within each species and interspecificallyEl registro fósil del Cretácico Inferior (Barremiense) de Las Hoyas incluye tres taxa de peces amiiformes. Dichos taxa, tradicionalmente asignados a las especies Caturus tarraconensis, Amiopsis woodwardi y Vidalamia catalunica, representan, sin embargo, tres especies nuevas. Estas tres especies son la base de un estudio multidisciplinar que tiene por objetivo comprender su paleobiología en el contexto de un ecosistema de tipo wetland. Desde un punto de vista filogenético, una de las especies representa un linaje primitivo, con una combinación en mosaico de caracteres de caturoideos y amioideos. La segunda especie es clasificada como plesión Vidalamiinae, y la tercera como un miembro de esta misma subfamilia. Un estudio paleobiogeográfico del orden Amiiformes, incluyendo las tres especies de Las Hoyas, muestra que el registro de este grupo se extiende al menos desde el Jurásico Inferior hasta nuestros días, alcanzando su máxima diversidad durante el Cretácico. Su distribución histórica se explica fundamentalmente en base a eventos de vicarianza que tuvieron en el Mar de Tethys su centro de origen. El análisis oseocronométrico de las marcas de parada de crecimiento detectadas en las escamas de las tres especies muestra que éstas presentaban patrones de crecimiento diferentes. El crecimiento de los peces amiiformes parece tener un componente filogenético, y estar fuertemente ligado a las condiciones ambientales, especialmente a la temperatura. Un estudio de experimentación actuotafonómica de descomposición de carcasas de peces actuales confirma que un ambiente dulceacuícola favorece una severa degradación de los tejidos. En consecuencia, debió existir un mecanismo de protección, como el crecimiento de tapetes microbianos, que permitiese la excepcional preservación del registro fósil de Las Hoyas. Además, la experimentación demuestra que las carcasas sufren procesos de abrasión por transporte incluso en sistemas de muy baja energía; la ausencia de indicios de abrasión en los peces amiiformes de Las Hoyas sugiere que su asociación en este yacimiento es de origen autóctono. La autoctonía de esta asociación permite interpretar la muestra de cada una de las tres especies de amiiformes como representativas de sus poblaciones originales. El análisis de la estructura poblacional de estas especies demuestra que éstas presentaban división de hábitats: los juveniles y adultos no habitaban en el mismo ambiente. El papel ecológico de las tres especies en el paleohumedal de Las Hoyas sería distinto tanto ontogenéticamente para cada especie como interespecíficament

Quantitative plant taphonomy: the cosmopolitan Mesozoic fern Weichselia reticulata as a case study

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 depositional environments. Moreover, palaeobiological insights are also obtained from the taphonomic analyses. In the case of the specimens of Weichselia reticulata included in this work, charred remains are the most frequent preservation type, and are the smallest and most homogeneous in size, probably due to the fragmentation of the fronds while burning and to the fact that burnt fragments are more fragile and break easily during the initial abrasion and attrition produced by transport. The size of charred fragments varies depending on the depositional environment, suggesting that biostratinomic processes, and not fire temperature, are the main cause for size differences, and providing valuable insight into the distance the remains might have travelled from production to final deposition. The taphonomic analysis suggests that Weichselia reticulata is allochthonous in all the localities analysed, and that its habitat would have been prone to fire and not far from freshwater systems. This case study shows promising results that can be implemented on different plant groups and chronostratigraphic ages, allowing for the proposal of a taphonomic modelWe would like to thank to the support of three grants awarded to CB-M by the SYNTHESYS Project http:// www.synthesys.info/ financed by the European Community Research Infrastructure Action under the FP7 Integrating Activities Program: BE-TAF-6350, FR-TAF-6323, GB-TAF6933. CB-M is supported by a Margarita Salas CA1/RSUE/2021–00703 scholarship from the Universidad Autonoma de Madrid and Ministerio de Universi- dades de Espana. This work is part of the project PID2019- 105546GB-I00 of the Ministerio de Ciencia e Inovación de Españ

A new trackway possibly made by a trotting theropod at the Las Hoyas fossil site (Early Cretaceous, Cuenca Province, Spain): Identification, bio-dynamics and palaeoenvironmental implications

A new trackway possibly made by a trotting theropod at the Las Hoyas fossil site (Early Cretaceous, Cuenca Province, Spain): Identification, bio-dynamics and palaeoenvironmental implication

On the importance of examining the relationship between shape data and biologically meaningful variables. An example studying allometry with geometric morphometrics.

Geometric morphometrics (GM) is a tool for the statistical analysis of shape on Cartesian landmark coordinates. However, because GM studies commonly focus on the description of morphological trends within shape space (or morphospace), the predictive power of multivariate statistics to understand morphological change remains underutilized. Here we show the protocols to study allometry in 3D with these tools on a postnatal growth series of the domestic chicken. We contrast three approaches: a ?traditional? one in which size variables are compared statistically, a Principal Components Analysis on size and shape scores (Procrustes  form space), and a multivariate regression. In the latter  approach we further used three different independent factors  inherently related to ontogeny: skull centroid size, body weight, and age of the specimens. The results clearly stress the importance of studying shape change in relation to different causal factors (i.e., with regressions), demonstrating that, indeed, any independent variable or variables that make biological sense can be used to understand morphological change with GM.Fil: Marugán-Lobón, Jesús. Universidad Autónoma de Madrid. Facultad de Ciencias; España;Fil: Blanco-Miranda, David. Universidad Autónoma de Madrid. Facultad de Ciencias; España;Fil: Chamero Macho, Beatriz. Universidad Autónoma de Madrid. Facultad de Ciencias; España; Provincia del Chubut. Fundación Egidio Feruglio. Museo Paleontológico;Fil: Martín-Abad, Hugo. Universidad Autónoma de Madrid. Facultad de Ciencias; España

A theropod trackway providing evidence of a pathological foot from the exceptional locality of Las Hoyas (upper Barremian, Serranía de Cuenca, Spain)

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 vertebrate trails (fish Undichna) and different impressions in the sediment. To address these complex settings, we devised a multidisciplinary approach, including the ichnological and taphonomical descriptions, characterisation of the rock lithofacies using thin-sections, 3D structured-light digitalisation with a high precision of 200-400 μm, and a geometric morphometric comparison with a large sample of bipedal dinosaur trackways. Sedimentary analyses showed that the trackway was produced in a humid, benthonic microbial mat, the consistency and plasticity of which enabled the preservation of the details of the movement of the animal. The results of the geometric analysis indicate that the 'wide-steps' of the trackway is not unusual compared to other trackways, providing evidence that it was made by a single individual with an estimated hip height approximately 2 m. Analogous pathologies in extant archosaurs that yield the combination of wide steps and deformed digits in the same trackway were considered. All results mutually support the hypothesis that a large theropod dinosaur, with a pathological foot, generated the trackway as it crossed an area of shallow water while slowly walking towards the main water source, thus stepping steadily over the benthonic mat over which multiple fish were swimming

A theropod trackway providing evidence of a pathological foot from the exceptional locality of Las Hoyas (upper Barremian, Serrania de Cuenca, Spain)

We describe a trackway (LH-Mg-10-16) occurring in laminated carbonated limestones of the Las Hoyas locality, Serranı´a 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 vertebrate trails (fish Undichna) and different impressions in the sediment. To address these complex settings, we devised a multidisciplinary approach, including the ichnological and taphonomical descriptions, characterisation of the rock lithofacies using thin-sections, 3D structuredlight digitalisation with a high precision of 200–400 μm, and a geometric morphometric comparison with a large sample of bipedal dinosaur trackways. Sedimentary analyses showed that the trackway was produced in a humid, benthonic microbial mat, the consistency and plasticity of which enabled the preservation of the details of the movement of the animal. The results of the geometric analysis indicate that the “wide-steps” of the trackway is not unusual compared to other trackways, providing evidence that it was made by a single individual with an estimated hip height approximately 2 m. Analogous pathologies in extant archosaurs that yield the combination of wide steps and deformed digits in the same trackway were considered. All results mutually support the hypothesis that a large theropod dinosaur, with a pathological foot, generated the trackway as it crossed an area of shallow water while slowly walking towards the main water source, thus stepping steadily over the benthonic mat over which multiple fish were swimmin

The Exceptional Fossil Site of Las Hoyas (SPAIN) from an Educational Perspective

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 impact, have made Las Hoyas to regularly be the center of attention in the local, national, and international media, especially since the reinterpretation of the paleoecosystem represented by the locality published in 2010. These results have led to a renaissance of the interest of the society for this unique site. As a consequence, Las Hoyas has been declared Site of Cultural Interest by the regional government, in the form of paleontological zone. This recognition, which grants the locality with the highest level of protection, sets a legal framework for the educative initiatives developed at this locality, which can be categorized as non-formal education, formal education, and Social Paleontology.Unidad de Paleontología, Departamento de Biología, Universidad Autónoma de Madrid, EspañaJURASSICA Museum, SuizaDepartment of Geosciences, University of Fribourg, SuizaMuseo Geominero, Instituto Geológico y Minero de España, EspañaDepartamento de Estratigrafía, Universidad Complutense de Madrid, EspañaGéosciences Rennes Unité Mixte de Recherche, Centre National de la Recherche Scientifique, FranciaDepartamento de Ecología, Universidad Autónoma de Madrid, EspañaLaboratoire de Géologie de Lyon: Terre, Planètes, Environnement, Unité Mixte de Recherche, Centre National de la Recherche Scientifique, Franci