The main culprit of the extinction of the dinosaurs, the largest predators on land that ever lived, is believed to have been an asteroid impact with our planet. However, a new study suggests that what wiped out dinosaurs was in fact caused by flowering plants, and that the asteroid put the nail on the coffin. Scientists believe that dinosaurs couldn’t get enough of the new flowers, but that they were also poisonous.
Researchers at the University of Baltimore in collaboration with the University at Albany conducted a study on what might truly have wiped out dinosaurs and revealed their findings in the journal Ideas in Ecology and Evolution. The study reveals that the toxic plants were deadly to the dinosaurs, because they were unable to develop taste aversions to the newly developed plants.
The researchers who conducted the study call this theory the Biotic Revenge hypothesis. According to them, the toxic plants developed and evolved with toxicity as a defense system. Also, dinosaurs apparently had trouble making the difference between the toxic plants and non-toxic plants and associate the difference in the smells and tastes. This is why they likely ate toxic plants that had lethal consequences. Given that dinosaurs were very large, they needed to eat large amounts of plants to survive.
On the other hand, the smaller dinosaurs were likely the ones that managed to develop taste aversions, as larger dinosaurs continued to eat them because they needed to survive. Nevertheless, this theory doesn’t ignore the asteroid impact that took its toll on the largest reptiles that ever lived, after it impacted Earth on the coast of Mexico. Instead, the theory aims to show that the toxic plants were the beginning of the end for them, while the asteroid truly wiped out dinosaurs.
The dinosaurs started dying out slowly due to the flowering plants. The study indicates that the flowering plants appeared in fossil records before the asteroid strike took its toll on dinosaurs. Since more plant-eating dinosaurs started dying, that implied that the food source for carnivorous dinosaurs was also disappearing. Some environmental factors also caused a decrease in plant-eating dinosaurs.
“A reason why most attempts to eliminate rats have not been successful is because they, like many other species, have evolved to cope with plant toxicity,” Gordon Gallup, professor and evolutionary psychologist said in a statement. “When rats encounter a new food, they typically sample only a small amount; and if they get sick, they show a remarkable ability to avoid that food again because they associate the taste and smell of it with the negative reaction.”
It’s worth mentioning that an interesting side effect of the development of toxic plants was that they were beneficial to mammals. There were more plants that developed a high number of edible fruits.
Researchers also conducted an analysis on modern descendants of dinosaurs, some birds and crocodiles. They were checking whether they are capable of developing taste aversions as opposed to their ancestors. The results showed that the birds were unable to develop taste aversions. However, they were able to develop aversions to the visual look of those plants that caused them to get sick. Crocodiles, on the other hand, continued eating the toxic food, hence not developing any taste or visual aversions towards toxic food.