The fossils of several feathered non-avian Maniraptoran dinosaurs
While the reason behind the extinction of the dinosaurs is a generally known fact, it was only in a recent study that we found out that the giant reptiles that ruled out planet in the past had been on the decline for some fifty million years before they went extinct.
This had to do with more than a single factor, as volcanic eruptions, the separation of the continents, and on-going climate change caused by billions of tons of carbon dioxide being pumped into the atmosphere all contributed to the dinosaurs’ slow but certain decline. But that’s not to say that had the asteroid not hit the dinosaurs would have still been extinct.
Oh no, they would likely have still been around today, only in a much different form than the one to which we are used. This is even proven by the fact that there are still members of the theropod class of dinosaurs still alive today. And yes, I am talking about birds.
But seeing as they evolved from dinosaurs that were alive sixty-six million years ago, how exactly did they manage to evolve? Well, according to a recent study from the Universities of Toronto and Alberta, seeds saved birds from the dinosaur extinction. Well, not birds as we know them today, but maniraptoran dinosaurs, a clave of small carnivorous theropods that largely resembled today’s birds.
So if the modern day birds’ ancestors were carnivorous and they were alive when the asteroid hit, how is it that we still have birds, and what did seeds have to do with anything? Well, as the climate was changing, as the dinosaurs were dying off, and as the sunlight was covered by a cloud of ash, food was beginning to be very scarce.
While meat was getting rarer and rarer, and plants couldn’t really photosynthesize with no sunlight, one of the very few sources of food remaining were seeds. Buried in the ground and viable for consumption for up to five decades, the dinosaurs that wanted to survive had to adapt to their new conditions.
Of course, larger dinosaurs couldn’t really survive on just seeds, so the smaller, carnivorous, toothed maniraptorans had to combine their meaty diet with plenty of seeds. Over time, they evolved so that they lost their teeth and started eating mostly seeds and other creatures smaller than them, eventually reaching the form of today’s birds.
One of the biggest problems with identifying that particular class of dinosaurs was that their bones were very fragile. So, it’s a very common occurrence for the only fossils encountered by scientists to be the teeth, as they tended to be stronger than the regular bones. This made it quite hard for the team to actually find out when maniraptorans evolved into birds, even if they tried to reverse engineer the process by following the birds’ ancestors instead of the dinosaurs’ descendants.
Image source: Wikimedia
