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.
