title: Palaeobiology: Argentinian unhatched pterosaur fossil.
abstract: Our knowledge of the eggs and embryos of pterosaurs, the Mesozoic flying reptiles, is sparse. Until now, the recent discovery of an ornithocheirid embryo from 121-million-year-old rocks in China constituted the only reliable evidence of an unhatched pterosaur. Here we describe an embryonic fossil of a different pterosaur from the Early Cretaceous lacustrine deposits of Loma del Pterodaustro (the Lagarcito Formation, which is about 100 million years old) in central Argentina. This new fossil provides insight into the eggshell morphology, early growth and nesting environments of pterosaurs.
authors.affiliation: Department of Vertebrate Paleontology, Natural History Museum of Los Angeles County, Los Angeles, California 90007, USA. chiappe@nhm.org
authors.forename: Luis M
authors.initials: LM
authors.lastname: Chiappe
authors.forename: Laura
authors.initials: L
authors.lastname: Codorniú
authors.forename: Gerald
authors.initials: G
authors.lastname: Grellet-Tinner
authors.forename: David
authors.initials: D
authors.lastname: Rivarola
mesh_terms: D000818:Animals; D001118:Argentina; D025061:Dinosaurs / Q000033:anatomy & histology* / Q000196:embryology*; D004528:Egg Shell / Q000033:anatomy & histology / Q000737:chemistry; D004625:Embryo, Nonmammalian / Q000033:anatomy & histology* / Q000196:embryology*; D005552:Forelimb / Q000033:anatomy & histology; D005580:Fossils; D006614:Hindlimb / Q000033:anatomy & histology; D049690:History, Ancient; D012886:Skull / Q000033:anatomy & histology; D014921:Wings, Animal / Q000033:anatomy & histology