An article published in the journal “Nature” describes a research on dinosaur eggs’ pigmentation and their link to bird eggs. A team of researchers led by molecular paleobiologist Jasmina Wiemann of Yale University analyzed 18 fossil dinosaur eggshells to look for traces of biliverdin and protoporphyrin pigments, the ones found in bird eggshells, finding them in Eumaniraptoran eggshells, a group that includes small carnivores such as Velociraptor. The conclusion is that pigmentation has a mimetic purpose that evolved in dinosaurs that created at least partially open nests.