A new Argentinean nesting site showing neosauropod dinosaur reproduction in a Cretaceous hydrothermal environment

GERALD GRELLET-TINNER; LUCAS FIORELLI

Nature Communications

Nature Publishing Group

Año: 2010 vol. 1 p. 1 - 8

2041-1723

Although several late Cretaceous sauropod colonial nesting sites have been discoverednearly on every continent during the last few decades, no studies have been performed todetermine the factors that underpinned the choice of these specifi c sites. Here, we report thefi rst defi nitive evidence of a group of sauropods that nested repetitively and purposely at aCretaceous hydrothermal site at Sanagasta, La Rioja Province, Argentina. The discovery of thisnew colonial nesting locality shows nest fi delity over a long time, and a symbiotic relationshipbetween egg clutches and a peculiar hydrothermal environment that favoured their incubation.Sedimentary and geochemical analyses of 80 clutches and their large eggs with thick eggshellssubstantiate that the Sanagasta sauropods were specifi cally using the soil moisture andthermoradiance to incubate their eggs, similar to a few extant species, namely, the megapode,Megapodius pritchardii , which is known to lay its egg clutches in burrows at volcanically heatednesting grounds.