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Updated: Jan 29, 2026

Processing Embryo, Eggshell, and Fungal Culture for Scanning Electron Microscopy
Published on: August 16, 2019
A mixed vertebrate eggshell assemblage from the Transylvanian Late Cretaceous
Mariela Soledad Fernández1,2, Xia Wang3, Mátyás Vremir4
1School of Biological Science and Technology, University of Jinan, Jinan, 250022, China.
Abstract:
A Late Cretaceous-aged multi-taxon nesting site from Romania preserved in three dimensions reveals the earliest example of nest site sharing yet known from the vertebrate fossil record. Eggshell and osteological evidence combined in this single accumulation demonstrate that at least four vertebrate taxa including enantiornithine birds and another avian of indeterminate affinities as well as crocodylomorphs and gekkotan squamates nested together in the same place. Colonial nesting in enantiornithines was previously described from this site; here, we present the first fossil evidence that other vertebrates also nested in the same place, perhaps exploiting the presence of the large bird colony. We describe four distinct eggshell morphotypes that have been collected from this site and draw palaeoecological inferences based on this unique multi-taxon nesting association.
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