66 million years ago, a devastating catastrophe ended the era of dinosaurs and caused the mass extinction of these huge animals. As descendants of dinosaurs, why can birds survive a mass extinction?
Birds are descendants of dinosaurs, and they are everywhere today. In fact, during the Cretaceous period, many birds appeared on Earth. Like dinosaurs, they faced the end of a mass extinction event in the Cretaceous, but in fact, they survived the disaster, and then evolved rapidly in the Great New Born. . To date, they have become the most important group of vertebrates on our planet.
Birds are descendants of dinosaurs and they are everywhere today.
In the dinosaur family there exists a group that is very close to the bird, the Deinonychosauria . Deinonychizardia is a group of dinosaur birds that lived from the late Jurassic period to the Late Cretaceous period, including two species of Troodontidae (Tailed-toothed dragon) and Dromaeosauridae . They are usually small in size, and their bodies are covered with feathers.
Troodontidae is a family of animal-like dinosaur dinosaurs. During the 20th century, fossils of this family were rarely found and so they were repeatedly classified into each major coelurosauria race. Recent complete fossils (including samples of feathers, eggs, embryos and adult offspring) have helped people learn more about them. Anatomical studies, especially those of primitive Troodontidae, such as Sinovenator, have shown anatomical similarities to Archeopteryx and primitive dromaeosaurids, and show that they are related to a clade. called paraves. This family is small and medium sized (1 - 100 kg) with unusual legs compared to other theropods.
Li Zhiheng's team from the Chinese Institute of Paleontology analyzed and compared the teeth samples of Deinonychosauria and ancient birds in the hope of finding the reason why birds could escape. from the extinction event that destroyed the dinosaurs.
The related study was published online in the academic journal "BMC Evolutionary Biology" on April 21. Through high-resolution penetrating microscopes and X-rays, the researchers compared teeth of Troodon, Anchiornis, Microraptor, Jeholornis, and other near-dinosaurs.
The microstructure shows the difference in tooth surface structure between dinosaurs and ancient birds living in the Mesozoic era . This difference is the existence of the structure of porous covered dentin.
Microstructure evolution inside the teeth of ancient birds and dinosaurs.
Porousmantle dentin is a structure between enamel and dentin. It is common in the teeth of carnivorous dinosaurs. Its function is to provide shock resistance, especially when predatory dinosaurs bite their prey. Simply put, dentin is a testament to the dinosaurs' violent hunting behavior.
In the study, paleontologists found that the teeth of the Mesozoic birds had no dentin , meaning that the ancient birds had a clear difference in eating habits with dinosaurs. , they choose to use seeds, berries and insects as their main food, some species become herbivores or omnivores. Such an evolutionary trend could be to avoid direct competition with the small carnivorous dinosaurs and occupy the ecological eyes of the food chain in order to survive.
Deinonychus (terrible claw) is a carnivorous dinosaur at the beginning of the Cretaceous, 3-4 m high, 5-6 m long, lightweight body so it can run very fast. It has a hard tail, probably used to steer and change direction quickly when chasing prey. This dinosaur has sharp teeth, strong front two claws to grab prey and tear prey with large claws on the hind feet.
Asteriornis maastrichtensis has no teeth in its mouth.
Not long ago, paleontologists named a species of Cretaceous bird found in Belgium, Asteriornis maastrichtensis . These birds lived during the last period of the dinosaur era, not only were they small in size but they had no teeth in their mouths. These are birds that are classified as omnivores and can eat anything found along the coast.
Asteriornis maastrichtensis can eat anything found along the coast.
After the great extinction event, a series of catastrophes caused the global ecosystem to collapse and be irreversible for a long time. The carnivores at the top of the food chain are most affected and eventually become extinct due to lack of food. But the birds have moved from eating meat to omnivores and plants, so they have a very high level of adaptation. After the extinction event, they can still find enough food to survive and continue to evolve to this day.
Meteors hit the Earth 66 million years ago .
. made the dinosaurs extinct.
The dietary changes of birds in the Mesozoic period have become the key to avoiding mass extinctions. However, paleontologists believe that there are other reasons besides the differences in diet, but they have not really figured out what those reasons are. But so far, the birds have preserved the "blood" of dinosaurs and occupied the sky in a new era.