@proceedings {4872, title = {Dinosaur eggshell and embryo localities in Lourinh{\~a} Formation, Late Jurassic, Portugal}, journal = {Journal of Vertebrate Paleontology, 29(3): }, year = {2009}, pages = {76A}, abstract = {

Four different localities from the Late Jurassic of Lourinh{\~a} formation with eggshells and embryos were studied: Paimogo (lower Amoreira-Porto Novo member), Peralta (Praia Azul member), Porto das barcas (Bombarral member) and Casal da R{\^o}la (Amoreira-Porto Novo member). All but Casal da R{\^o}la have embryonic material. Preliminary results show that eggshells from Paimogo correspond to obliquiprismatic morphotype (0.92mm thick), similar to those from Morrison Formation. Within Paimogo site a different type of eggshell was discovered, having a radial section of 153 μm with a mammilary layer measuring 65 μm. Porto das Barcas eggshells represent a discretispherulitic morphotype (1,23 mm thick).
This locality presents a nest 60-cm diameter containing many eggshells but an indeterminate number of eggs. Some embryonic bones were discovered between the eggshells including teeth and skull bones showing that the eggs belong to a saurischian, tentatively a sauropod dinosaur. Peralta nest eggshells are preliminary ascribed to obliquiprismatic morphotype (column: 0,56mm and mammilla: 0,21mm) probably related to Paimogo{\textquoteright}s nest taxon (Lourinhanosaurus). Peralta site bears embryonic bones namely small theropod teeth associated with bone fragments, and unidentifiable dinosaur vertebra. Only eggshells have been collected at Casal da R{\^o}la (ML1194). The eggshells (0,78mm thick) are prismatic morphotype and it was impossible to determine the pore system, the outer surface is smooth with no ornamentation.
Lourinh{\~a} formation has the oldest sauropod and theropod nest with embryos known so far.

}, attachments = {https://docentes.fct.unl.pt/sites/default/files/omateus/files/castanhinhaetal2009dinosaureggshellp.pdf}, author = {Castanhinha, R and Ara{\'u}jo, R. and O. Mateus} }