A new study suggests that human ancestors lived with dinosaurs for a short time before the reptilian beasts went extinct, reported New York Post.

Researchers have concluded their study — published in the journal Current Biology — by analysing the fossils of the group in which humans, dogs and bats were included, allowing experts to finally dig through the mystery.

It is suggested that when the destructive asteroid hit Earth 66 million years ago, it killed all the dinosaurs except birds and other small animals, such as lizards and frogs — an event termed the Cretaceous-Paleogene (K-Pg) mass extinction.

As the palaeobiologists observed the fossil record, they reached a point where they put forth that placental mammals existed prior to the destruction that led to extinction.

The author Emily Carlisle of Bristol’s School of Earth Sciences said: “We pulled together thousands of fossils of placental mammals and were able to see the patterns of origination and extinction of the different groups and based on this, we could estimate when placental mammals evolved.”

According to the research, Primates (the human lineage), Lagomorpha (rabbits and hares) and Carnivora (dogs and cats) evolved right before the extinction of the ancient large-sized species.

“The model we used estimates origination ages based on when lineages first appear in the fossil record and the pattern of species diversity through time for the lineage,” co-author Daniele Silvestro from the University of Fribourg shared.

Researchers believed that the lack of competition from dinosaurs allowed placental mammals to diversify and evolve.

“Unfortunately we don’t know what our placental mammal ancestors would have looked like back then,” Carlisle admitted.

“Many of the earliest fossils of placental mammals are quite small creatures such as Purgatorius — an early ancestor of primates – which was a small burrowing creature a bit like a tree shrew. So it’s likely that many of our ancestors were small and squirrely.”