In the magazine Elhuyar Zientzia eta Teknika of May, we issued a news related to the mammal boom. In this news we could read that they have carried out a research based on fossils and DNA and that they have seen that the mammal boom had nothing to do with the disappearance of dinosaurs. Booma occurred about 15 million years after the disappearance of dinosaurs. Likewise, this study noted that placental mammals were formed between 100 and 85 million years before the destruction of dinosaurs.
So far it has been considered that mammals proliferated enormously at the end of the pressure of the dinosaurs and that some 65 million years ago there was a boom.
In June, in the journal Nature, they published an article on another research that reaffirms what was previously thought. According to this article, the boom occurred immediately after the disappearance of dinosaurs. The research adds that it was then, and not before, when the ancestors of mammals with placenta emerged that exist today. This latest research, based exclusively on fossils, is the most extensive research ever done based on fossils.
What fossils and molecules say, once again, do not coincide. In a short time they have published two investigations that have given a totally different result on the same subject, one of them taking into account the DNA molecule of current mammals, and another not. The results of both methods have already been different. For example, fossils claim that there have been plants on Earth for 475 million years, while molecules already existed 700 million years ago.
At the moment we will not know when and where the mammals were formed, nor if their boom had to do with the dinosaurs.