Digging into the molecules of fossil dinosaur eggs

Dinosaurs roamed the earth 65 million years ago, and ancient researchers and amateur fossil hunters are still tracing them today. The minerals in fossil eggs and shell fragments provide snapshots of the early life of these organisms and their fossil processes. Now, researchers reporting on ACS Earth and space chemistry have analyzed the molecular makeup of fossil dinosaur eggs from Mexico and found evidence of nine amino acids and ancient protein structures.

Current studies show that all dinosaurs lay eggs, although most do not escape the test of time. Since whole eggs and shell fragments are very rare fossils, their mineral composition has not been extensively explored. Earlier, Abel Moreno and colleagues reported the micro-structure of eggshells from a wide variety of dinosaurs found in Baja California. Although other teams have shown that there are some dinosaur nests Calcium carbonate, Carbohydrates and other compounds, none of the organisms’ tiles collected by Moreno’s team made similar analyzes. So, as a next step, these researchers wanted to look at minerals Organic carbonBasic elements in fossilized eggshells from hatchlings in the late Cretaceous.

The researchers collected five fossil eggs from the Theropod (bipedal carnivorous) and hydrosuride (duck-built dinosaur) families and dinosaurs in unidentified otoxins. Calcium carbonate was found to be the primary mineral, containing small amounts of albite and quartz crystals. Anhydride, hydroxyapatite and iron oxide contaminants were also present in the shells, which the researchers say replaced some original minerals during the fossil record. Later, by Fourier Transform Infrared Spectroscopy (FT-IR), the team detected nine amino acids in five samples, but all of them contained only lysine. In addition, they found evidence of secondary protein structures, including twists, α-helixes, β-sheets, and irregular structures, which have been preserved for millions of years by being engraved in minerals. Related FT-IR bands Amino acids And the secondary structures represent previously unclassified ancestral proteins, the researchers say.