Most of us have heard of Archaeopteryx – the so-called first bird..the missing link if you like, between the dinosaurs that we know from the fossil record and the modern feathered creatures we love to see in our gardens…..
Well – it turns out that dinosaurs were covered in feathers long before they tried to get off the ground.
Modern birds are descendants of a particular branch of medium-sized predatory dinosaurs called therapods. If you think you don’t know what a therapod looked like, think again because Tyrannosaurus Rex was one of these two-legged meat eaters, as was the smaller velociraptor, made famous by the film Jurassic Park.
Just like their descendants, these dinosaurs were warm-blooded and they evolved feathers rather than fur to keep warm because – current thinking says – of their acute colour vision.
Mammals generally have rather poor colour vision because they tended to be nocturnal during the early stages of their evolution, but reptiles and birds have extremely good vision.
Not only did dinosaurs have the three colour receptors for red, green and blue that humans have, but they probably also had (like their closest living relatives today – crocodiles and birds) the ability to see extremely short-wave and ultra-violet light.
Before dinosaurs evolved feathers, they had hairs similar to a mammal’s fur and these hairs gradually turned into feathers which are much better for optical signalling. The broad, flat surface area of feathers allowed for the constant refraction of light which is absolutely essential to produce blues and greens as well as the metallic shimmering we find so attractive about birds’ plumage.
By developing feathers, dinosaurs were able to show off across the colour spectrum and be warm-blooded animals at the same time, which is something mammals have never (yet) managed…