Revision of the Barremian fern Coniopteris laciniata from Las Hoyas and El Montsec (Spain): Highlighting its importance in the evolution of vegetation during the Early Cretaceous

The species Coniopteris laciniata and Sphenopteris wonnacottii are heterophyllous ferns recovered from two Spanish Barremian localities, Las Hoyas and El Montsec respectively. The similarities between these species, observed in a study of a total of 66 hand specimens from both localities, indicate that they are conspecific. Following the rule of priority in botanical nomenclature, and because there are doubts about the assignment of this species to a higher taxonomic rank, the name Coniopteris is maintained. Characters of this fern and additional characters of other species of Coniopteris would support a diversification of polypod ferns during the Early Cretaceous. Metric architecture analyses suggest that the heterophylly of the plant was probably caused by the submersion of the apical part of fronds in water during their development, which would be consistent with the taphonomy of the remains in both localitiesWe would like to thank El Montsec housed at the Muséum national d’Histoire naturelle (Paris, France), which was visited with support of a grant from the SYNTHESYS Project (http://www.synthesys.info/), financed by the European Community Research Infrastructure Action under the FP7 Integrating Activities Program. Candela Blanco-Moreno is supported by a Margarita Salas Postdoc CA1/RSUE/2021-00703 scholarship funded by the Spanish Ministry of Universities and Universidad Autónoma de Madrid. This work is part of the project PID2019-105546GB-I00 of the Spanish Ministry of Science, Innovation and Universitie

Variación morfológica y alometría de las vértebras precloacales en el ofidio daboia russelli (viperidae)

Understanding the variation of the ophidian vertebral morphology is an essential tool in snake paleobiology, but so far this field remains hardly investigated. A major problematic is the still scarce knowledge about the basis of homogeneity of intracolumnar shape variation along the vertebrae of the precloacal region in these animals. For instance, this variation can be overwhelmingly low in cases such as in vipers, for which it seems almost impossible to describe a concrete regionalization of the precloacal region without ambiguity. This study has applied geometric morphometrics to analyze if the shape variation of the vertebrae of the precloacal vertebrae of an adult specimen of Daboia russelli allows differentiating any sort of parcellation within the column of this organism. We have also explored if size is associated with the organization of vertebral shape along the axial skeleton. The multivariate analyses showed that the main pattern of vertebral shape variation in D. russelli concerns the neural spine and the hypapophysis, whereas the shape of the vertebral centrum appears to be nearly invariant along the series. Our analysis also showed that the precloacal region can be sudivided into two portions that merge in a transitional boundary of largest vertebrae in the middle of the column. From this middle region towards the distal ends of the column vertebrae become smaller changing their shapes in two antithetical waysFunds provided by the project CGL2009-11838 BTE and a FPU grant (AP2007-00904; MICINN) to I. Sarri

Helminth eggs from early cretaceous faeces

Many thanks go to David Porcel Muñoz and Isabel Sánchez Almazo at the microscopy service of the Centro de Instrumentación Científca (CIC) at Universidad de Granada (Spain), for allowing us to use the optical microscope and for carrying out the SEM analyses, respectively. Many thanks also go to Dr Maria Teresa Galán Puchades (Universidad de Valencia, Spain) for her comments in some of the parasite pictures. Funding for the analyses was provided by the Spanish Ministerio de Economía y Competitividad (MINECO) through the project CGL-2013-42643-P and PID-2019-105546GB-I00. Te fellowship reference BES-2014-070985 of the Program for the Training of Researchers of the MINECO is associated to the project CGL-2013-42643P.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 classifed into distinct morphotypes. Several parasitic eggs were retrieved from two of these coprolites, confrming the second record of digenea trematode eggs and nematode (ascaridid) eggs from an Early Cretaceous locality. The cylindrical coprolite containing anisakid eggs was likely produced by a crocodylomorph as the parasite host, whereas the bump-headed lace coprolite indicates the role of a fsh as an intermediary or defnitive host of the trematodes and ascaridids. These trace and body fossils show that the Las Hoyas 126–129 Ma lacustrine ecosystem documents the early connection between basal Gonorynchiformes fsh and digenetic trematodes.Spanish Ministerio de Economía y Competitividad (MINECO) through the project CGL-2013-42643-P and PID-2019-105546GB-I0

Soft-tissue and dermal arrangement in the wing of an Early Cretaceous bird: Implications for the evolution of avian flight

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 integument of the wing and other connective structures associated with the insertion of flight feathers. The integumentary anatomy, and myological and arthrological organization of the new fossil is remarkably similar to that of modern birds, in which a system of small muscles, tendons and ligaments attaches to the follicles of the remigial feathers and maintains the functional integrity of the wing during flight. The new fossil documents the oldest known occurrence of connective tissues in association with the flight feathers of birds. Furthermore, the presence of an essentially modern connective arrangement in the wing of enantiornithines supports the interpretation of these primitive birds as competent fliersSupport and funds were provided by the projects CGL2009-1183 BTE and CGL-2013-42643-P, Juntas de Comunidades de Castilla-La Mancha and by donations from Mrs. Gretchen Augustyn to the Dinosaur Institute of the Natural History Museum of Los Angeles Count

The Gobiosuchidae in the early evolution of Crocodyliformes

<p>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, <i>Cassissuchus sanziuami</i>, gen. et sp. nov., as the sister taxon of the Asian clade <i>Gobiosuchus</i> + <i>Zaraasuchus</i>. The family Gobiosuchidae is diagnosed by a large number of synapomorphies, such as the presence of extensively sutured palpebrals, ridges on the dorsal surface of the posterolateral region of the squamosal, a longitudinal ridge along the dorsolateral surface of the surangular, appendicular osteoderms, and closure of the supratemporal fenestra. Specimens attributed to <i>Lisboasaurus estesi</i>, a putative gobiosuchid, are evaluated and the taxon regarded as a nomen dubium. <i>Cassissuchus sanziuami</i> provides new evidence on the anatomy of the pectoral and pelvic girdles and the forelimb morphology in Gobiosuchidae. The phylogeny of basal Crocodyliformes supports the nested sequence of three clades: Protosuchidae, Gobiosuchidae, and ((<i>Shantungosuchus</i> + <i>Sichuanosuchus</i>) + Shartegosuchidae), but their interrelationships are only partially solved. The early evolution of Crocodyliformes is further characterized by the high number of phenotypic specializations, many of which are related to the dermal skeletal overgrowth of the temporal region, palpebrals, and osteoderms.</p> <p>http://zoobank.org/urn:lsid:zoobank.org:pub:5317CCDB-FA28-4748-9712-1BC27A166108</p> <p>SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at <a href="http://www.tandfonline.com/UJVP" target="_blank">www.tandfonline.com/UJVP</a></p> <p>Citation for this article: Buscalioni, Á. D. 2017. The Gobiosuchidae in the early evolution of Crocodyliformes. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1324459.</p

The serrated teeth of Sebecus and the iberoccitanian crocodile. A morphological and ultrastructural comparison

[ES] Se compara la morfología y ultraestructura del esmalte de dientes aserrados de cocodrilos. La muestra está compuesta por coronas aisladas atribuidas a la forma iberoccitana (Eoceno de la cuenca del Duero) y Sebecus (S. ?huilensis y S. icaeorhinus del Mioceno medio de Colombia y Eoceno inferior de Argentina). Se examinaron caracteres cuantitativos y cualitativos de la corona y sus márgenes aserrados. En este sentido, se han explorado todas las variables que caracterizan la simetría de la corona dentaria, diferenciando los dientes más grandes de Sebecus ?huilensis de los de la forma iberoccitana. El análisis de la ultraestructura evidencia una organización pseudoprismática del esmalte de Sebecus ?huilensis, contrastando con el modelo aprismático del cocodrilo iberoccitano. En este artículo se definen los dientes aserrados como aquellos que poseen carenas con dentículos aislados. Un dentículo aislado es una unidad morfológica discreta. Esta definición excluye los dientes con carenas crenulados formadas por crestas anastomosadas convergentes, que proceden de la ornamentación del esmalte. También, se evalúan aspectos funcionales de los dientes considerando los microdesgastes observados en los dentículos aislados.[EN] The morphology and enamel ultrastructure of serrated teeth of crocodiles is compared. The sample is composed by isolated teeth attributed to the iberoccitanian form (Eocene of the Duero basin, Spain) and Sebecus (S. ?huilensis and S. icaeorinus, Eocene of Argentine and middle Miocene of Colombia). Quantitative and qualitative characters of the tooth crown and serrations are examined. Exploration of new significant morphological characters of the tooth crown is essayed. In this sense, it has been raised several variables that discern symmetry of the tooth crown, differentiating the larger teeth of Sebecus ?huilensis from the iberoccitanian ones. Ultrastructural analysis also evidenced a pseudoprismatic organization of the enamel of S. ?huilensis contrasting with the aprismatic pattern of the iberoccitanian crocodile. Here serrated teeth is defined as those that posses carinae with isolated denticles. An isolated denticle is a discrete morphological unit. This definition excludes teeth with coarse carinae, builded from convergent anastomosed ridges that coming from the ornamentation of the crown enamel. Functional aspects of the teeth are evaluated considering the microware patterns observed on the isolated denticles

The late Barremian ecosystem of Las Hoyas sustained by fishes and shrimps as inferred from coprofabrics

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 exhibit a microcrystalline calcium phosphate groundmass lacking recrystallization and containing fine inclusions. Three different coprofabrics have been characterized and reflect the diet and digestive processes of the animal producers. The fish scale coprofabric is formed by ganoine scales likely attributed to Semionotiformes; the decapod cuticle coprofabric includes exoskeletal fragments which might be assigned to Atydae shrimps and Astacidae crayfish prey. A combination of decapod cuticles and fish scales can occasionally occur in the same coprolite. The third coprofabric contains few or no inclusions, and likely denotes the presence of coprolite producers with very efficient digestive systems. The exceptional preservation of the Las Hoyas coprolites reveals the trophic importance of small crustaceans with thin and delicate exoskeletons, a food resource that is not usually evident in coprolites. The number of coprofabrics relative to the number of possible fecal producers is low, and may reflect taphonomic biases. Nevertheless, the coprofabric contents demonstrate that decapods and fishes were important food resources in this Barremian ecosystemFunding for the analyses was provided by the Spanish Ministerio de Economía y Competitividad (MINECO) through the project CGL2013-42643-P. The fellowship reference BES-2014-070985 of the Program for the Training of Researchers of the MINECO helped fund this project, and the PhD travel grant reference EEBB-I-2018-12926 “Ayudas a la movilidad predoctoral para la realizacion de estancias breves en centros de I þ D00 of the MINECO made it possible to carry out this work at the University of Colorado Boulde

El cocodrilo de El Viso (Zamora): Consideraciones acerca de los "Zifodontos" (Metasuchia, ?Sebecosuchia) del Eoceno de la Cuenca del Duero

[ES] Los distintos fragmentos recogidos en El Viso (Madridanos, Zamora; Eoceno medio) son interpretados, de forma preliminar, como pertenecientes a un cocodrilo > primitivo. Anteriormente los ejemplares con estas características presentes en la Cuenca del Duero habían sido atribuidos al género Iberosuchus Antunes, pero dado que el material analizado hasta la fecha no permite aceptar o rechazar esta denominación se ha optado por aplicar el término, no formal, de cocodrilos Iberoccitanos a algunos de los especímenes de la Cuenca del Duero.[EN] The different fragments collected in El Viso (Madridanos, Zamora Middle Eocene) are interpreted, in a preliminary way, as belonging to a crocodile > primitive. Earlier specimens with these characteristics present in the Duero Basin, were assigned Iberosuchus Antunes, but as the material discussed so far do not allow or reject this designation,it has been chosen to apply the term, crocodiles Iberoccitanos

The Las Hoyas Lagerstätte: a palaeontological look to an Early Cretaceous wetland

Fig. S1 and systematic lis

Food web reconstruction through isotopic compositions of fossil faeces: insights into the ecology of a late Barremian freshwater ecosystem (Las Hoyas, Cuenca, Spain)

A total of 54 coprolites with different morphologies from the Konservat-Lagerstatte of Las Hoyas (upper Barremian, Cuenca, Spain) were analysed for stable isotopes (δ15N and δ13Corg) to examine the food-web structure of this ancient wetland. The Las Hoyas wetland exhibited wetter and drier periods that indicated water table oscillations. Differences in the δ15N values of coprolites collected from wetter and drier facies were probably due to different baseline δ15N values during the dry periods (higher) compared to those of the wetter periods. The δ13Corg values indicated that aquatic food resources were the most commonly used by the animals from Las Hoyas. Assuming a Trophic Enrichment Factor (TEF) of + 2.5 ‰, three trophic levels were established for the coprolite association. All the specimens of circular, ellipsoidal, elongated, and rosary morphotypes fell into the same trophic level, whereas other morphotypes (cylinder, irregular, and thin lace) exhibited a wide range of δ15N values and the highest % N concentrations. The covariation between δ15N and δ13Corg values describe a wide spectrum of values across the middle and upper part of the ecosystem's food web structure, suggesting that the Las Hoyas ecosystem hosted specialist feeders and omnivorous and/or opportunistic feeders, the latter being the majority. The variation of δ15N values within the specimens of some morphotypes showed that the larger coprolites do not exhibit any correspondence between the faecal size and δ15N valuesThis work was supported and financed by the Spanish Ministerio de Economía y Competitividad (MINECO) thorough the project CGL2013-42643P, the PhD grant BES2014- 070985 associated with this project, and the travel grant EEBB-I-17-12028 “Ayudas a la movilidad predoctoral para la realizacion de estancias breves en centros de IþD