After the asteroid crash into Earth 66 million years ago, it is possible that some toothless birds still survived thanks to their ability to forage.
Birds evolved from dinosaurs about 160 million years ago. In fact, birds and dinosaurs lived together for about 100 million years. Birds originated from a group of dinosaurs called Dromaeosaurs, or “running lizards”, a family of feathered theropods.
66 million years ago, when an asteroid crashed into Earth in the sea off the coast of present-day Mexico, the dinosaurs were wiped out. However, some bird species continue to exist.
Scientists specializing in the study of bird evolution strive to understand why birds do not go extinct. They pieced together clues like fossils and other evidence of life on ancient Earth to come up with some theories about why birds survived, although there’s no definitive answer yet.
Birds today have no teeth. Instead, they have beaks of many different shapes and sizes for eating and drinking. During the time of the dinosaurs, some birds still had teeth, others did not.
After the asteroid hit Earth, all toothed birds became extinct, but many toothless species continued to live. Some scientists believe that their toothless nature has helped them survive.
Ancient toothless bird fossils show that they were more likely to eat plant-based foods, especially seeds and fruits. This means that, compared to birds with teeth, they are less dependent on eating other animals.
Ichthyornis disparan ancient toothed seabird that lived during the late Cretaceous period (about 100 million – 66 million years ago) in North America. Image: Michael Hanson/Bhart-Anjan S. Bhullar
Some scientists believe that this difference in diet became a great advantage after the meteorite strike. At that time, the event immediately caused severe tsunamis and earthquakes. The massive heat pulse from the impact caused large-scale forest fires near the asteroid landing site. In the following months, a large amount of dust filled the atmosphere surrounding the Earth, blocking out the Sun, causing plants to receive little light to grow.
For herbivores, food becomes extremely scarce. Many species became extinct, causing problems for hunters. Many animal species were wiped out and plants also had difficulty getting enough sunlight, so food would be difficult to find. But if it has the ability to peck the ground and find buried seeds or nuts to eat, that animal can survive.
Of course, there are other factors that cause toothless birds to survive while their toothed siblings perish, including luck. For now, it’s a mystery that hasn’t been fully resolved.
Scientists will come up with ideas or hypotheses based on existing knowledge and information. They then test the idea by conducting experiments or gathering more evidence. This information will either strengthen or refute the original idea. So scientists are ready to tweak the story of how birds survived and dinosaurs died out as they gather more information from ancient rocks, fossils and DNA.