A new research study says that modern birds owe their survival to their ancestors, who could peck on seeds after the meteor impact that wiped out the dinosaurs from earth.
The study says that the bird-like dinosaurs survived the meteor strike because of their diet. The study also explains why no modern bird has a beak lined with teeth.
The impact was followed by a ‘nuclear winter’ as the meteor impact changed the climate of the Earth and blotted out sunlight.
The dust in the atmosphere that emanated from the asteroid strike obscured sunlight and blocked photosynthesis.
However, researchers said that the seeds that had already built up in the ground would have still been available as a food source for the birds that had a beak capable of eating them.
The study suggests that the seeds still in the ground may have helped sustain small toothless bird ancestors until the extreme climatic conditions began to get better on the planet.
The theory was outlined in the journal Current Biology.
The loss of vegetation deprived the plant-eating dinosaurs of food, which in deprived the meat eaters of their food.
“After this meteor, you’re left with essentially a nuclear winter where really not much is growing, the plants aren’t able to grow to provide nourishment for plant-eaters and then meat-eaters aren’t able to access plant-eaters if they’ve all perished,” said lead researcher Derek Larson, from the University of Toronto.
“We think that the survival of birds had something to do with the presence of their beak.”
Study of Fossil teeth
For the study, the researchers analyzed more than 3,000 fossilised teeth from bird-like dinosaurs known as maniraptorans, who are considered the closest relatives of modern birds.
At the end of the Cretaceous period, most of the maniraptorans disappeared, including the toothed birds.
“We came up with a hypothesis that it had something to do with diet,” Mr Larson said.
“Looking at the diet of modern birds, we were able to reconstruct a hypothetical ancestral bird and what its likely diet would have been,” he told the BBC’s Science in Action programme.
“What we’re envisaging is a seed-eating bird, so you’d have a relatively short and robust strong beak, which would be able to crush these seeds.”
The research team came up with the suspicion that the seed diet might have played a part in the survival of the ancestors of modern birds.
“We might be looking at a very different picture of bird diversity had certain groups not evolved the ability to eat seed material,” Mr. Larson said.
Mr Larson said most of today’s birds owe their existence to their seed-eating ancestors.