Birds are the only living amniotes with colorful eggs that have long been considered an avian innovation. A recent study took a second look at egg shells to demonstrate the egg color backgrounds in birds.
Scientists at Yale University have found that all colors and spots on modern bird eggs are derived from a single evolutionary source among dinosaurs.
Part of the discovery originated from a pigment analysis found on 18 samples of fossil dinosaur bark from around the world. The scientists tested the presence of two eggshell pigments and found them in egg shells belonging to Eumaniraptoran dinosaurs, which include small carnivorous dinosaurs, eg Velociraptor.
But the puzzle for scientists was whether the pigments found in the eggshells of dinosaurs meant that the eggs looked different to the naked eye. A certain level of pigment may have existed in the chemical composition of the shells, without showing the external color of the eggs.
Yale paleontologist Jasmina Wiemann said: "We have shown that our analytical approach really targets egg color and not just egg pigmentation, because we need substantial concentrations of the red pigment, protoporphyrin, to induce a positive signal for the egg. color of the egg. The result is the same. The color of the egg had a unique evolutionary origin in the eumaniraptoranos ".
"We have had the opportunity to directly address your question and test – thanks to the Yale Peabody Museum of Natural History egg collection – if there is, in fact, evidence for the red pigment in Siamese crocodile eggshells. We have shown that there are no detectable amounts of protoporphyrin in the eggshells of the Siamese crocodiles. "
A new follow-up study published the week of June 20 in the journal Nature indicates that Wiemann's initial conclusion was correct.