Miguel Moreno-Azanza

University of Zaragoza | UNIZAR · Departamento de Ciencias de la Tierra

Abnormalities in the histo- and ultrastructure of the amniote eggshell are often related to diverse factors, such as ambient stress during egg formation, pathologies altering the physiology of the egg-laying females, or evolutionarily selected modifications of the eggshell structure that vary the physical properties of the egg, for example increasi...

Abstract Crocodiloid eggshell is considered to be one of the most conservative among amniotes. This contrasts with the high body diversity observed within the crocodylomorph lineage, which extebds from the Triassic to the present. This incongruence raises a fundamental question in palaeology: is the crocodylomorph eggshell structure that conservati...

Protocol for electron backscatter diffraction (EBSD) analysis of fossil eggshells

Iguanodontia is a diverse clade of herbivorous ornithischian dinosaurs that were speciose and abundant during the Jurassic and Cretaceous. Although the monophyly of Iguanodontia is well supported, their internal relationships have sparked heated debate due to several phylogenetic paradigm shifts. Late Jurassic basally branching iguanodontians in pa...

Here we describe archosaur remains from the Late Triassic (Norian) from Jameson Land, East Greenland. Five sandstone blocks were recovered from Sydkronen site (Bjergkronerne Member, Ørsted Dal Formation) on the Harvard expedition of 1992. This material was preliminary assigned as indeterminate theropod material, however it has remained unstudied un...

Los dinosaurios ornitópodos, y en particular los iguanodontios, fueron componentes esenciales de los ecosistemas continentales barremienses (Cretácico Inferior) en el sur de Europa si consideramos la frecuencia con la que aparecen registrados en asociaciones fósiles de esa edad. La Formación Mirambel, en la subcuenca de Morella (cuenca del Maestraz...

Se ha realizado el estudio histológico de dos costillas de un ornitópodo estiracosterno iguanodóntido del yacimiento Pepe de la Formación Mirambel (Barremiense, Cretácico Inferior), ubicado en el anticlinal de Ladruñán (subcuenca de Morella, Cuenca del Maestrazgo) en el noreste de la provincia de Teruel. Los elementos postcraneales recuperados (un...

Virtual palaeontology is a growing field, leading palaeontologists to better understand the microanatomy of many extinct species. The application of techniques such as CT and μCT-scanning allows the researchers to study micro-anatomical features in a non-invasive way and make inferences on the palaeobiology of animals. Dinosaurs have been extensive...

O Jurássico Superior da Bacia Lusitânica apresenta diversas associações florísticas associadas à deposição de sequências continentais. O afloramento de Valmitão, localizado a oeste de Ribamar, parte da Formação Lourinhã, revelou presença abundante de Porochara maxima e P. cf. pedunculata (?) recolhidas de um nível de margas acinzentadas, onde dente...

Two eggs (L29 and N28) were recovered in the Holocene site of Lobos 3, (Islote de Lobos, north Fuerteventura, Canary Islands), the site has been interpreted as a purple dye workshop from the Early Roman Empire Epoch. For the first time, eggs from a Holocene deposit of the Canary Islands have been analyzed in terms of size, shape, and biomineral str...

Surface collecting is the first and sometimes the only type of sampling carried out in many fossiliferous localities, including vertebrate microfossil assemblages. Nevertheless, it is rare to test how representative these surface-collected samples are of the palaeobiocoenosis. A first approach to the palaeontological analysis of Los Menires, a Barr...

The fossil record of dinosaur eggs is highly biased; in contrast to the relatively rich egg record for theropods and sauropodomorphs, the characteristics of ceratopsian eggs have remained unknown because of an absence of embryo-containing eggs. On the basis of well-preserved Protoceratops (Ceratopsia) and Mussaurus (Sauropodomorpha) eggs, Norell et...

Crocodylomorph eggs and eggshells are known as old as the Late Jurassic and are frequent components of most multiootaxic eggshell assemblages. Classified within the oofamily Krokolithidae, thei histo- and ultrastructures are conservative throughout geological time, characterised by inverted-trapezoid-shaped shell units that grow from highly spaced...

The pan-sirenian Bauplan is conservative, probably owing to the constraints of adaptation to an aquatic lifestyle. Gathering morphological data from extinct forms is complex, resulting in poorly resolved phylogenies for stem pansirenians. Extant sirenians ossify the falx cerebri and the tentorium cerebelli, membranes of the dura mater of the brain...

Albanerpetontidae form an enigmatic extinct group of lissamphibians, ranging from the early Bathonian to the early Pleistocene. The Upper Jurassic outcrops of Portugal yield a large collection of material, suitable for addressing the intraspecific variation in and diagnostic potential of the characteristic fused frontals. We revise 58 specimens fro...

The South American sauropodomorph egg record is unrivaled in its richness, with Jurassic and Early and Late Cretaceous eggshell occurrences of up to six different oospecies, included in the oofamilies Megaloolithidae, Fusioolithidae and, probably, Faveoloolithidae, and the oldest putative soft-shelled eggs of the fossil record. In addition, numerou...

The origin of the last sauropod dinosaur communities in Europe and their evolution during the final 15 million years of the Cretaceous have become a complex phylogenetic and palaeobiogeographic puzzle characterized by the controversy on the alleged coexistence of immigrant, Gondwana-related taxa alongside relictual and insular clades. In this conte...

Since their discovery in the 1920s, some asymmetric, elongated dinosaur eggs from the Upper Cretaceous of Mongolia have been interpreted as ceratopsian eggs. However, recent views support a maniraptoran affinity mainly based on macroscopic features. Technical advancements in palaeontology provide a novel approach to diagnose maniraptoran eggs, and...

The Upper Jurassic Lourinhã Formation is well known for its rich assemblage of fossil vertebrates. In this formation, ornithopod dinosaurs are represented by two iguanodontian species, Eousdryosaurus nanohallucis and Draconyx loureiroi. We recently became aware of unreported material belonging to the holotype of Draconyx loureiroi, consisting of pa...

Upper Cretaceous outcrops of the South-Central Pyrenees in northeastern Spain show a rich palaeontological record of eggs and eggshells of vertebrates, in particular dinosaurs. The fossil site of Blasi 2B (Arén, Huesca) is added to the oological record of the Late Maastrichtian, with an association of at least five ootypes of dinosaur eggshells (on...

The Sobrarbe-Pirineos UNESCO Global Geopark, located in the Central Pyrenees, is a region of remarkable geodiversity that includes extensive Eocene fossil-bearing sites and constitutes an important archive of paleobiodiversity. The Sobrarbe-Piri-neos Geopark hosts outcrops of Eocene formations bearing an unusual abundance and diversity of fossils f...

Found in the Upper Jurassic outcrops of Lourinhã, Portugal, and first published in 1997, the Paimogo dinosaur egg clutch is one of Portugal’s most remarkable fossils, with over one hundred eggs preserved in association with embryonic bones, of the allosauroid theropod Lourinhanosaurus. However, many questions about it have remained unanswered, even...

The Upper Jurassic Lourinhã Formation is a siliciclastic continental unit, which yielded a diverse vertebrate fauna, dated from upper-most Kimmeridgian to lower-most Tithonian. Among dinosaurians, extremely diverse and abundant were saurischians, while ornithischians are extremely rare. In 1991, Museu da Lourinhã excavated a specimen of a medium-si...

The Eocene record of turtle eggshells is scarce, with a single unconfirmed report from France. This scarcity contrasts with the great abundance of osteological remains, distributed over a wide palaeogeographical range as a result of climatic warmth. In this paper, we describe the first definitive Eocene Testudoolithidae eggshell fragments attributa...

Iguanodontian dinosaurs are common in Early Cretaceous deposits across all Europe but their Jurassic relatives are somewhat less well understood, with few remains described in Iberia and England. Most of what is currently known from the Iberian record comes from the Upper Jurassic Lourinhã Formation, in west-central Portugal. The only well-establis...

Throughout the evolutionary history of Avialae, several members of this clade have evolved into giant forms, in different time periods and ecological contexts. In Europe, the first birds that show this condition, the Gargantuaviidae, occur during the Late Cretaceous (late Campanian–early Maastrichtian), but it is during the Paleogene when more grou...

Both cerebral hemispheres are separated by a membrane projection of the brain dura matter, which is attached to the ventral surface of the parietal named the falx cerebri. Another membrane, the tentorium cerebelli, separates the upper surface of the cerebellum and the occipital lobes. These membranes ossify in some mammals such as primates, marsupi...

The South-Pyrenean Basin (northeastern Spain) has yielded a rich and diverse record of Upper Cretaceous (uppermost Campanian−uppermost Maastrichtian) vertebrate fossils, including the remains of some of the last European dinosaurs prior to the Cretaceous-Paleogene (K-Pg) extinction event. In this work, we update and characterize the vertebrate foss...

Ornithopods are one of the most speciose group of herbivorous dinosaurs, rising during the Jurassic and getting extinct at the Cretaceous–Paleogene boundary. However, most of the attention has been given to derived forms (hadrosaurids). Herein, cranial and post-cranial ornithopod material from the Upper Jurassic Lourinhã Formation and housed at Mus...

Thin fossil eggshell from Upper Cretaceous deposits of Europe, characterized by nodular ornamentation similar to modern gekkotan eggshell, has mostly been interpreted as gekkotan (=‘geckoid’) in origin. However, in some cases, as for the oogenus Pseudogeckoolithus, a theropod affinity has also been suggested. The true affinity of these fossil ‘geck...

Crocodylomorphs were a diverse clade in the Late Jurassic of Portugal, with six taxa reported to date. Here we describe 126 isolated teeth recovered by screen-washing of sediments from Valmitão (Lourinhã, Portugal, late Kimmeridgian–Tithonian), a vertebrate microfossil assemblage in which at least five distinct crocodylomorph taxa are represented....

Crocodylomorphs were a diverse clade in the Late Jurassic of Portugal, with six taxa reported to date. Here we describe 126 isolated teeth recovered by screen-washing of sediments from Valmitão (Lourinhã, Portugal, late Kimmeridgian–Tithonian), a vertebrate microfossil assemblage in which at least five distinct crocodylomorph taxa are represented....

The site of Gran Dolina (Atapuerca, Spain) has a 19-metre-thick Lower and Middle Pleistocene infilling, divided into eleven levels. This work is focused on the level TD6 (0.8–0.9Ma), consisting of a succession of debris flow and fluvial facies with a high diversity of vertebrates, including Homo antecessor. Here we describe for first time eggshell...

Welcome to EAVP 2018, this year in Caparica, Portugal, hosted by the Faculdade de Ciências e Tecnologia of Universidade Nova de Lisboa. The Annual Meeting of the European Association of Vertebrate Palaeontology is one of the most important and renowned conferences of its kind. Every year, hundreds of researchers from all over Europe and other cont...

An enlarged theropod manual ungual (CSC1-4) from the Weald facies of Spain is described. The claw was found in the fossil locality of Caña Seca 1, Teruel province, within the El Castellar Formation of early Barremian (Early Cretaceous) in age. CSC1-4 is morphologically closer to megalosauroids than to any other theropod clade bearing enlarged manu...

Sirenians are the only extant herbivorous mammals fully adapted to an aquatic lifestyle. They originated in Africa during the Paleocene from an undetermined clade of afrotherian mammals, and by the end of the Eocene they were widely distributed across the tropical latitudes. Here we introduce Sobrarbesiren cardieli gen. et sp. nov. It is the first...

A review of the onset of the synrift sedimentation and synsedimentary extensional tectonics of the Oliete sub-basin (north- western Maestrazgo basin, East Spain) is presented here based on new data acquired after extensive sedimentological, struc- tural and palaeontological analysis of the Barremian Blesa Fm. The lower boundary of the Blesa Fm is a...

Here we describe an unusually high concentration (several tenths of thousands) of turtle eggshell fragments from the Castejón de Sobrarbe-41 (CS-41) fossil site (Lutetian, middle Eocene). CS-41 is a sirenian dominated bonebed located in the Sobrarbe Formation, Ainsa Basin, Huesca, Northern Spain. CS-41 is associated with overbank settings, related...

The sauropod of El Oterillo II is a specimen that was excavated from the Castrillo de la Reina Formation (Burgos, Spain), late Barremian–early Aptian, in the 2000s but initially remained undescribed. A tooth and elements of the axial skeleton, and the scapular and pelvic girdle, represent it. It is one of the most complete titanosauriform sauropods...

Detail of the excavation of the scapula MDS-OTII,14.