Science and life on earth

Survivors of the Last Extinction Crisis – by Richard Flament

66 million years ago, the age of the dinosaurs ended in a movie-worthy story about the end of the world. Meteors, extreme climates and volcanic eruptions have made life so hostile to any terrestrial being that dinosaurs died during this catastrophe. However, not all of them disappeared. A group of feathered dinosaurs repeatedly managed to withstand the climatic blasts that persisted on Earth at the time.

In popular ideas, it is common to think that dinosaurs have been extinct for a long time, when in fact they are very diverse today. Heirs of a colossal reign, these last survivors are simply all birds. So why would birds get away with it and not big dinosaurs like Tyrannosaurus Rex or other sauropods?

The main reason for the disappearance of large dinosaurs (and other living creatures during this period) is the disruption of the food chain due to various weather events that occurred 66 million years ago. Thus, vegetation, prey and predators were greatly affected. Not to mention the massive asteroid that crashed in Chicxulub, Mexico, which destroyed much life on impact and possibly obscured Earth for years.

As for our dear birds, or “dinosaur birds,” they managed to survive without much harm thanks to their different diets of carnivores and herbivores. At least this is the most likely hypothesis. In fact, birds are very opportunistic and therefore have the opportunity to prey on a variety of foods, such as seeds or insects. They also reproduced faster than other dinosaurs, so they will renew a new group more quickly.

Tens of millions of years of evolution pushed the surviving dinosaurs into what we now know about the diversity of birds. In some birds, such as ostriches, rheas, and helmeted cassowaries, claw morphology is used in the film to recreate what may have been the paws of a carnivorous dinosaur in the secondary stage. At the same time, they are dinosaurs… Who knew we could still see them today?

Richard Flament, PhD student in evolutionary biology at Qatar University