New research is now showing that what may have killed off the dinosaurs wasn't just due to the asteroid impact. This new research puts forward that the massive dinosaurs met their doom with the arrival of flowering plants.
The gigantic creatures couldn't stop eating the new flowers.
A study from researchers at the University of Baltimore and the University at Albany was published in the journal Ideas in Ecology and Evolution. It shows that dinosaurs could not stop eating toxic plants. Dinosaurs were unable to develop taste aversions to these new plants.
Researchers in the study refer to this theory as the Biotic Revenge hypothesis. They say that herbivorous plants were pressured to develop and evolve with toxic and chemical defenses.
Dinosaurs were not able to learn to associate toxic plants with tastes and smells. This could have led the dinosaurs to consume harmful or lethal doses of the poisonous plants. Because of the dinosaurs' large size, they indiscriminately ate large amounts of plants to sustain their energy levels.
Smaller dinosaurs that are the descendants of birds were more likely to develop these taste aversions. Larger dinosaurs continued to eat them because it was required for their survival.
This theory doesn't dispute that the asteroid killed off the dinosaurs during the impact off the coast of Mexico. What it shows instead is that the asteroid was what finished off the dinosaurs. Instead, dinosaurs were already starting to decline because of the emergence of flowering plants. Flowering plants began to appear in the fossil record before the asteroid strike that killed off the dinosaurs.
This had a chain reaction among the species of dinosaurs. While carnivorous dinosaurs didn't eat plants, they did eat the herbivores. As more herbivores would die, the food source for carnivorous dinosaurs would disappear as well. Environmental factors are also cited as a cause for the decrease in plant-eating dinosaurs.
One of the unintended side effects was that the emergence of toxic plants benefited mammals. Plants were starting to develop an increasing number of edible fruits.
Their work didn't end with just flowers. Researchers also ran tests on the modern descendants of dinosaurs: bird and crocodiles. They checked if these groups of animals were able to develop taste aversions unlike their ancestors.
Researchers say that while birds couldn't develop taste aversions, they were able to develop aversions to the visual characteristics of the food that made them sick. Birds were still able to determine which foods were poisonous. Crocodiles did not develop taste aversions similarly to their ancestors and just kept eating toxic food.