Some experts have long believed that the cause of extinction of dinosaurs 65 million years ago was the fall of a massive asteroid. However, a new analysis of the professor of psychology at the University of Albany shows that dinosaurs were in trouble long before the fall of the asteroid. Professor and evolutionary psychologist Gordon Gallup and his former student Michael Frederick, now working at the University of Baltimore, argue that the emergence of toxic plants in combination with the inability of dinosaurs to associate the taste of certain foods with danger led to their population having already declined sharply at the time of the fall of the asteroid .
The acquired taste disgust is an evolutionary defense that can be found in many species in which the animal learns to associate the use of a plant or other food with a negative bubbled consequences, such as a feeling of sickness. To explain the protective mechanism, Gallup cites the example of rats.
“The reason most attempts to destroy were unsuccessful is that they, like many other species, evolved to cope with the toxicity of plants,” says Gallup . “When rats meet new foods, they usually try only a small amount, and if they are ill, they demonstrate a remarkable ability to again avoid this food, because they associate the taste and smell with it with an unpleasant reaction.”
What dinosaurs became extinct?  The first flowering plants, called angiosperms, appear in fossils long before the fall of the asteroid and just before the dinosaurs began to gradually disappear. Gallup and Frederic argue that as the plants developed and the development of toxic defense, dinosaurs continued to consume them, despite gastrointestinal disorders. Although there is uncertainty about when flowering plants became poisonous and how long it took to spread this feature, Gallup and Frederick note that their appearance coincides with the gradual disappearance of dinosaurs.
In addition to studying the spread of toxic plants even during the life of dinosaurs, Gallup and Frederic investigated whether birds (which are considered descendants of dinosaurs) and crocodiles (also descendants) can acquire taste disgust. It turned out that the birds, instead of getting used to the taste, developed an aversion to the visual characteristics of what they felt bad about. They knew what they should not eat to survive. In a previous study in which 10 crocodiles were fed different kinds of meat, some of which were slightly toxic, Gallup found that, like dinosaurs, crocodiles did not learn to understand tastes.
“Although the asteroid was certainly important, the psychological deficit , because of which dinosaurs were unable to refrain from eating certain plants for food, had a serious impact on them, “says Gallup. “The widespread view of the disappearance of dinosaurs associated with the fall of the asteroid implies that the disappearance of dinosaurs should have been sudden, but it is clearly the opposite: dinosaurs began to disappear long before the fall of the asteroid and continued to disappear gradually over millions of years after it.”