The size of an adult of one of the most terrible dinosaurs in the history of the planet, a tyrannosaur, could reach 12 m - it was a real giant. However, his cubs at the time of leaving the egg shell were very tiny in comparison with their parents. This conclusion was reached by a Canadian-Scottish group of scientists after examining the remains found in the formations of Alberta and Montana.
It should be clarified right away that no dinosaur eggs have yet been found that could be attributed with great accuracy to the tyrannosaurus rex clutch. The bones of the cubs have to be studied, and the fact that not so few of them have been found confirms the hypothesis. Young tyrannosaurs were small and weak, often fell prey to predators before they grew up, so their small bones were at the disposal of scientists.
Scientists have performed 3D scans of the bones of close relatives of Tyrannosaurus, Daspletosaurus and Albertosaurus. Both died at an early age, shortly after hatching from their eggs. In the first case, it was possible to study a fragment of the jaw with embryos of teeth, in the second, the same undeveloped claw - these were obviously babies. Comparing the proportions, scientists came to the conclusion that the tyrannosaurus at the beginning of its life reached only 90 cm in length - like a not very large dog.
Inside the egg, a small carnivorous dinosaur was folded, so it took up very little space - the egg was hardly more than 430 mm in length. This still makes tyrannosaurs one of the largest creatures in history ever born from eggs. It is all the more surprising how much effort it took a small reptile to grow into a real monster.