The ancestors of humans and dinosaurs coexisted on Earth

Statistical analyzes of fossils show that placental mammals, which are among the ancestors of humans, and dinosaurs coexisted on Earth.

Bristol (England). The impact of a large asteroid led to the extinction of all non-avian dinosaurs about 66 million years ago. The event is known in science as the Cretaceous-Paleogene (K-Pg) boundary mass extinction event. It is disputed whether placental mammals, which belong to the ancestors of man, actually existed alongside the dinosaurs at this time, or whether they only appeared after the extinction of the dinosaurs.

Fossil finds of placental mammals in rock layers formed only after the asteroid impact suggest that this group of animals appeared after the mass extinction. However, molecular data has long suggested that placental mammals may have existed prior to this time point.

Statistical analysis of fossils

researchers University of Bristol and the University of Freiburg about her Emilie Carlyle in the specialist magazine Current Biology He has now published a study that, based on statistical analysis of fossils, has determined that placental mammals existed before the mass extinction and thus lived on Earth with dinosaurs for a short period of time.

“By collecting thousands of placental mammal fossils, we were able to see patterns of formation and extinction of different groups. On this basis, we were able to estimate when placental mammals appeared.”

Evolution after the extinction of the dinosaurs

However, it appears that the evolution of modern lineages of placental mammals did not begin until after the asteroid impact. This suggests that they were better able to diversify once the dinosaurs were gone.

Current Biology, doi: 10.1016/j.cub.2023.06.016