Experts ‘size up' age of Russia’s first dinosaur egg find, showing evolution of birds
The exceptional treasure was unearthed several years ago in the Kemerovo Region. According to the scientists, the egg belongs to a carnivorous dinosaur-troodontidae, which is seen as an ancestor to modern birds. The results of the paleontologists' study confirming this assessment was published at the beginning of November in the journal Historical Biology. The researchers have estimated the age of the finding to be about 100 million years old.
«The troodontidae egg was found by our colleague Yevgeny Maschenko from the Institute of Paleontology in (the Russian Academy of Sciences RAS) Moscow with whom we have been working together on a National Geographic funded project. At that time, we were carrying out excavations at the Shestakovo-3 deposit (in the Kemerovo Region). The egg was tucked away in a layer of thick reddish clay, and therefore it was extremely difficult to distinguish it because only the eggshell’s contour could be seen. This find was a huge stroke of luck for paleontologists because this is the first and only one of its kind in Russia,» stated Stepan Ivantsov, research assistant from the Laboratory of Mesozoic and Cenozoic Continental Ecosystems at TSU.
A study of the shell’s thin cross-sections under an electron microscope, demonstrated just how closely similar the troodontidae egg structures are with those of eggshells of modern birds. This fact provides additional evidence that all ‘our feathered friends' inhabiting the Earth nowadays are descendants of carnivorous dinosaurs which during the course of evolution have changed their appearance and lost teeth.
About 90% of the remains of the ancient pangolins found at different times at Shestakovo-3 are Psittacosaurus — primitive horned dinosaurs. The bones of their carnivorous fellows have been rarely seen here, but the egg found during the last joint expedition belongs namely to carnivores. This is also confirmed by the internal structure of the eggshell. The diameter of the egg measures only two centimeters. Indeed, adult troodontidae species were rather insignificant in size — up to one meter tall.
The Shestakovo complex in the Kemerovo Region became popular in the middle of the previous century. During the last 60 years, paleontologists have found various remains at this spot of different dinosaurs ranging from small carnivores to 30-meter tall Sauropods, as well as Siberian Psittacosaurus inhabiting this area 130 million years ago. The previously unearthed skeletons are stored now in the Novosibirsk, Tomsk, and Moscow institutions that obtained permission to carry out excavations.