Eggs Embryos Nest

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Moreno-Azanza, M., Pérez-Pueyo M., Puértolas-Pascual E., Núñez-Lahuerta C., Mateus O., Bauluz B., Bádenas B., & Canudo J. I. (2022).  Cáscaras de huevo de los últimos cocodrilomorfos del Cretácico (Huesca, España). XXXVII Jornadas de Paleontología SEP - V Congreso Ibérico de Paleontología. p. 119. Abstract2022_moreno-azanza_etal_sep.pdf


Moreno-Azanza, M., Balauz B., Ezquerro L., Coimbra R., Mateus O., & Nuñez-Lahuerta C. (2022).  Unbroken dinosaur eggs accumulated together do not guarantee autochthony of the fossil assemblage. Journal of Taphonomy. 16(1-4), 129-130. Abstractmoreno-azanza_et_al_2020_unbroken_eggs.pdf


Ezquerro, L., Balauz B., Coimbra R., Nuñez-Lahuerta C., Mateus O., Román T., & Moreno-Azanza M. (2021).  Evidence of sedimentary remodel of Jurassic theropod egg clutches (Lourinhã, Portugal). 18th Conference of the EAVP-Abstract book. 72-73. Abstractezquerro_et_al_2021_sedimentary_remodel.pdf


Azanza, M. M., Coimbra R., Puértolas-Pascual E., Russo J., Bauluz B., & Mateus O. (2019).  Crystallography of Lourinhanosaurus eggshells (Dinosauria, Theropoda, Allosauroidea). Journal of Vertebrate Paleontology, Program and Abstracts. 156-157.moreno_azanza_et_al_2019_svp_abstract.pdf
Russo, J., Mateus O., Marzola M., & Balbino A. (2017).  Two new ootaxa from the late Jurassic: The oldest record of crocodylomorph eggs, from the Lourinhã Formation, Portugal. PLOS ONE. 12, 1-23., 03, Number 3: Public Library of Science Abstractrusso_et_al_2017_two_new_ootaxa.pdfWebsite

The Late Jurassic Lourinhã Formation is known for its abundant remains of dinosaurs, crocodylomorphs and other vertebrates. Among this record are nine localities that have produced either dinosaur embryos, eggs or eggshell fragments. Herein, we describe and identify the first crocodiloid morphotype eggs and eggshells from the Lourinhã Formation, from five occurrences. One clutch from Cambelas, composed of 13 eggs, eggshell fragments from Casal da Rola and Peralta, one crushed egg and eggshells from Paimogo North, and four crushed eggs as well as eggshell fragments from Paimogo South. We observed and confirmed diagnostic morphological characters for crocodiloid eggshells and which are consistent with a crocodylomorph affinity, such as the ellipsoidal shape, wedge-shaped shell units, triangular extinction under cross-polarized light, and tabular ultrastructure. This material is distinctive enough to propose two new ootaxa within the oofamily Krokolithidae, Suchoolithus portucalensis, oogen. and oosp. nov., for the material from Cambelas, the most complete clutch known for crocodiloid eggs, and Krokolithes dinophilus, oosp. nov., for the remaining material. These are the oldest crocodylomorph eggs known, extending the fossil record for this group to the Late Jurassic. Furthermore, except for the clutch from Cambelas, the material was found with theropod eggs and nests, in the other four occurrences, which seem to suggest some form of biological relationship, still unclear at this point.

Moreno-Azanza, M., Bauluz B., Canudo J. I., & Mateus O. (2017).  The conservative structure of the ornithopod eggshell: electron backscatter diffraction characterization of Guegoolithus turolensis from the Early Cretaceous of Spain. Journal of Iberian Geology. 1-9., 2017 Abstractthe_conservative_structure_of_the_ornithopod_eggshell.pdfWebsite

The Spheroolithidae oospecies Guegoolithus turolensis, putatively attributed to non-hadrosauroid styracosterns was first described in the Barremian of the Iberian Basin, and later reported in the Valanginian–Hauterivian of the Cameros Basin, with both occurrences separated by a few hundred kilometres but by over 10 million years.

Moreno-Azanza, M., Gasca J. M., Canudo J. I., Lázaro B. B., & Mateus O. (2016).  The evolution of the ornithischian eggshell: State of the art and perspectives. Abstracts with Programs, the 2016 Annual Meeting, the Palaeontological Society of Japan. 6., Fukui, Japanmoreno_azanza_et_al_2016_the_evolution_of_the_ornithischian_eggshell.pdf
Marzola, M., Russo J., & Mateus O. (2015).  Identification and comparison of modern and fossil crocodilian eggs and eggshell structures. Historical Biology. 27(1), 115-133. Abstractmarzola_et_al_2015_identification_and_comparison_of_modern_and_fossil_crocodilian_eggs_and_eggshell_structures.pdfWebsite

Eggshells from the three extant crocodilian species Crocodylus mindorensis (Philippine Crocodile), Paleosuchus palpebrosus (Cuvier's Smooth-fronted Caiman or Musky Caiman) and Alligator mississippiensis (American Alligator or Common Alligator) were prepared for thin section and scanning electron microscope analyses and are described in order to improve the knowledge on crocodilian eggs anatomy and microstructure, and to find new apomorphies that can be used for identification. Both extant and fossil crocodilian eggs present an ornamentation that vary as anastomo-, ramo- or the here newly described rugosocavate type. The angusticaniculate pore system is a shared character for Crocodylomorpha eggshells and some dinosaurian and avian groups. Previously reported signs of incubated crocodilian eggs were found also on our only fertilised and hatched egg. Paleosuchus palpebrosus presents unique organization and morphology of the three eggshell layers, with a relatively thin middle layer characterised by dense and compact tabular microstructure.

Stockdale, M., Benton M., & Mateus O. (2014).  Cracking dinosaur endothermy: paleophysiology unscrambled. Journal of Vertebrate Paleontology. Program and Abstracts, 2014, 235-236.stockdale_et_al_2014_eggshells_abstract_svp.pdf
Russo, J., Mateus O., Balbino A., & Marzola M. (2014).  Crocodylomorph eggs and eggshells from the Lourinhã Fm. (Upper Jurassic), Portugal. Comunicações Geológicas. 101, Especial I, 563-566. Abstractrusso_et_al_2014_crocodylomorph_eggs_and_eggshells_from_the_lourinha_fm_upper_jurassic_portugal.pdf

We here present fossil Crocodylomorpha eggshells from the Upper Jurassic Lourinhã Formation of Portugal, recovered from five sites: one nest from Cambelas with 13 eggs, and three partial eggs and various fragments from, Paimogo N (I), Paimogo S (II), Casal da Rola, and Peralta. All specimens but the nest were found in association with dinosaur egg material. Our research reveals that on a micro- and ultrastructural analysis, all samples present the typical characters consistent with crocodiloid eggshell morphotype, such as the shell unit shape, the organization of the eggshell layers, and the triangular blocky extinction observed with crossed nicols. We assign the material from the Lourinhã Formation to the oofamily Krokolithidae, making it the oldest crocodylomorph eggs known so far, as well as the best record for eggs of non- crocodylian crocodylomorphs. Furthermore, our study indicates that the basic structure of crocodiloid eggshells has remained stable since at least the Upper Jurassic.