Eggs Embryos Nest

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Cunha, P. P., Mateus O., & Antunes M. T. (2004).  The sedimentology of the Paimogo dinosaur nest site (Portugal, Upper Jurassic). 23 rd IAS Meeting of Sedimentology. 93., Coimbra, Portugal Abstractcunha_p_p_2004_-_the_sedimentology_of_the_paimogo_dinosaur_nest_site_portugal10467.pdf

Sedimentological features of the Paimogo site, 6 km NNW of Lourinhã, western central Portugal are presented. More than one hundred theropod dinosaur eggs (some containing embryo bones) ascribed to Lourinhanosaurus antunesi Mateus 1998, three crocodilian eggs and some other fossils were found at the 32 m2 excavated area of the egg-bearing horizon (Mateus et al., 1998). The stratigraphic position of the site is the Praia Azul member (Lourinhã Formation), roughly corresponding to the Kimmeridgian-Tithonian boundary or, more likely lowermost Tithonian. The maximum flooding surface of the basinal transgressive event where the horizon is located corresponds to the base of the H depositional sequence defined by Pena dos Reis et al. (2000) and probably correlates to the base of sequence Ti1 identified within western European basins (Jacquin et al., 1998), dated as 150 Ma. Possibly during the normal river discharge, the theropods congregated in nesting colonies at the backswamp of an extensive flood plain with small meandering channels and freshwater ponds. There are no evidences that the nest was dug or the eggs buried. The eggs have probably been laid on a flat, shaded, muddy area near the bank of a large pond. It is probable that the eggs have not been actively incubated. The larger number of eggs suggest that they were laid near simultaneously by, at least, six females. The fossil record shows that crocodilians, mammals, gastropods and fish were also present. A flood event occurred when theropod embryos had attained a late stade of ontogenetic development, probably just before hatching. The overflow from a nearby channel flooded the plain, including the area where the eggs had been laid. The sheet flood flowing over the nest resulted into the scattering and breaking up of some dinosaur eggs. Eggshell and embryos skeletal parts fragments were displaced to an adjacent area where, due to hydrodynamic decline, the flow submerged other clutches and moderately dragged their eggs. The flooding caused the drowning of the embryos and covered the eggs with fine-grained sediment, hiding them from predators and scavengers. Hydrodynamic interpretation of the arrangement of the theropod eggs and egg-fragments suggests that the flow came from the NW. When the floodwaters receded, the fine-grained deposits became exposed to subaerial weathering. Although the sediment surface was often wet and small bodies of standing water may still have existed, the sediments were oxidized and plant remains have consequently been destroyed. Some carbonate cementation and redenning resulted from pedogenesis under alternating dry and moist conditions, in a semiarid/ sub-tropical climate under seasonal changing, contrasting conditions. The thick, stratigraphically above and below the nesting horizon mudrocks indicate a long persistence of periodic flooding, alternating with pedogenesis. During the early stages of diagenesis, vertical pressure crushed the eggs. Silt penetration into the inner part of each egg inhibited later flattening during the burial process.

de Ricqlès, A., Mateus O., Antunes M. T., & Taquet P. (2001).  Histomorphogenesis of embryos of Upper Jurassic Theropods from Lourinha (Portugal). Comptes Rendus De L Academie Des Sciences Serie Ii Fascicule a-Sciences De La Terre Et Des Planetes. 332, 647-656., Jan Abstractricqles_mateus_et_al_2011_histomorphogenesis_of_embryos_of_upper_jurassic_theropods_from_lourinha_portugal.pdfWebsite

Remains of dinosaurian embryos, hatchlings and early juveniles are currently the subject of increasing interest, as new discoveries and techniques now allow to analyse palaeobiological subjects such as growth and life history strategies of dinosaurs. So far, available ‘embryonic’ material mainly involved Ornithopods and some Theropods of Upper Cretaceous age. We describe here the histology of several bones (vertebrae, limb bones) from the tiny but exceptionally well preserved in ovo remains of Upper Jurassic Theropod dinosaurs from the Paimogo locality near Lourinhã (Portugal). This Jurassic material allows to extend in time and to considerably supplement in great details our knowledge of early phases of growth in diameter and in length of endoskeletal bones of various shape, as well as shape modelling among carnivorous dinosaurs. Endochondral ossification in both short and long bones involves extensive pads of calcified cartilages permeated by marrow buds. We discuss the likely occurrence of genuine cartilage canals in dinosaurs and of an avian-like ‘medullary cartilaginous cone’ in Theropods. Patterns of periosteal ossification suggest high initial growth rates (20 μ m·day−1 or more), at once modulated by precise and locally specific changes in rates of new bone deposition. The resulting very precise shape modelling appears to start early and to involve at once some biomechanical components.

Mateus, I., Mateus H., Antunes M. T., Mateus O., Taquet P., Ribeiro V., & Manuppella G. (1998).  Upper Jurassic Theropod Dinosaur embryos from Lourinhã (Portugal). Mem. Acad. Ciências de Lisboa. 37, 101-109. Abstractmateus_et_al_1998_-_upper_jurassic_theropod_dinosaur_embryos_from_lourinha_portugal_-_upper_jurassic_palaeoenvironments_in_portugal_ed._....pdfWebsite

Upper Jurassic nesting site from Paimogo (Lourinhã, Portugal) yielded the oldest dinosaur theropod embryos ever found. Numerous bones, including skull bones, from the skeleton of these embryos have been collected. The study of bones and embryos offers the possibility to learn more on the early life of theropod dinosaurs.

Mateus, O., Taquet P., Antunes M. T., Mateus H., & Ribeiro V. (1998).  Theropod dinosaur nest from Lourinhã, Portugal. Journal of Vertebrate Paleontology. 18, 61A., Number (Suppl. 3) Abstractmateus_et_al_1998_theropod_dinosaur_nest_from_lourinha_portugal_svp.pdfWebsite

More than 100 well preserved dinosaur eggs have been discovered in the Upper Jurassic levels (Tithonian) of Lourinhã, Portugal. The eggshels dispersed in a big area with 11 meters in the highest diameter with high concentration in the middle.

Mateus, I., Mateus H., Antunes M. T., Mateus O., Taquet P., Ribeiro V., & Manuppella G. (1997).  Couvée, oeufs et embryons d'un dinosaure théropode du Jurassique supérieur de Lourinhã (Portugal). C.R Acad. Sci. Paris, Sciences de la terre et des planetes. 325, 71-78., Jully, Number 1 Abstractmateus_et_al_1997_eggs_embryos_nest__couvee_oeufs_et_embryons_dun_dinosaure_theropode_du_jurassique_superieur_de_lourinha_portugal.pdfWebsite

Several well preserved clutches of dinosaurs have been discovered in the upper Kimmeridgian/ Tithonian of Lourinhã (Estramadur Province, Portugal). Some eggs of one clutch contained embryo elements of a theropod dinosaur. The egg-shell resembles that of eggs which have been discovered in the Upper Jurassic of Colorado