Scientists discovered how fish conquered the seas after the extinction of the dinosaurs

After the extinction of dinosaurs 66 million years ago, modern groups of fish rapidly occupied the vacated ecological niches and in just a few million years came to dominate the oceans.

This is the conclusion reached by paleontologists who discovered fossils aged 62.2 million years in Egypt. The results of the study were published in the journal Science Advances.

In Egypt's Eastern Desert, scientists found the remains of 21 fish species belonging to nine different orders. Among them were the oldest known representatives of several groups that remain widespread in seas and oceans to this day.

The find dates to the so-called "Patterson's Gap" — a period lasting approximately 10 million years after the asteroid impact, during which fish fossil remains are extremely rare. Due to the lack of data, scientists were long unable to determine which species survived the catastrophe and how modern marine ecosystems were formed.

The study showed that many ancient fish lineages likely did indeed disappear along with other victims of the mass extinction. In their place, representatives of Perciformes — the largest group of modern fish, which includes tuna, mackerel, perch, and thousands of other species — rapidly spread across the oceans.

According to the authors, it was the mass extinction that created the conditions for the rapid evolution of new fish groups. The ecological niches freed up after the disappearance of previously dominant species allowed them to quickly assume key positions in marine ecosystems.

Additional analysis showed that the first modern fish communities may have formed in tropical seas and then gradually spread across the entire world.