Thursday, 5 July 2012

Birds of a Feather, or should that be Dinosaur?

So why bird watch? This is a pastime that attracts people from diverse backgrounds. It has quite a bit going for it. It gets you outdoors, you get to visit some beautiful, interesting places, you also get to meet other birdwatchers if you choose, or you can watch alone.
For me there is another reason, for me, it is Dinosaur watching. There is now lots of compelling evidence that feathers first developed on Dinosaurs. The first inkling we had of this was with the stunningly beautiful and enigmatic fossil of Archaeopteryx. Archaeopteryx is considered a 'transitional' creature. It is thought that it did not fly like most birds today, but would glide from one tree to another, similar to mammalian gliders, such as the sugar glider, do today. There are now quite a number of fossils that have been found, and continue being found that show the delicate filaments of keratin that left some dinosaurs fierce and fluffy! 
The first feathers were similar to the feathers that the ostrich or emu sports. Thin, fluffy filaments that were not yet designed for flight, but would have been wonderful for insulation and quite likely used for display. Some Dinosaurs were already capable of fearsome displays. Triceratops for example, had vascularisation throughout it's large bony plate. This meant that when blood was pumped through these vessels the skin over the bony plate would turn bright red. Of course no one really knows why Triceratops could do this, but we do know that other animals use similar techniques to show physical prowess during breeding seasons, or to ward off predators. 
Another clue is that scales, claws and feathers are made of the same material, Keratin. We also have Keratin, it makes up our hair and fingernails. Scientists have even managed to fiddle with the genes of chickens to switch on (or off) feathers or scales. The bone structure of birds and dinosaurs is also incredibly similar.
There have been many feathered dinosaur fossils recovered from Jurassic and Cretaceous deposits in northeastern China, the most exciting one so far in my opinion is Yutyrannus huali (meaning beautiful feathered tyrant). A very large carnivorous dinosaur that is thought to have been more or less covered in feathers. It weighs in just under 1.5 tons, that is a whole lot of feathery dinosaur! So far, Yutyrannus huali is the largest dinosaur found to date that had feathers.
So when I watch a magpie strutting around the lawn and singing, or a flock of finches flitting from the edge of a creek into grass, or the breeding displays of the Victorias rifle bird, or a cassowary slowly moving through the rainforest (the most dinosaurian looking of all!). I imagine that the behaviours we see in birds reflects some of the behaviours of the long lost dinosaurs. The fossils and feathers trapped in amber (like the ones at the top of my blog) come to life right before my eyes. I don't need scientists to  engineer me a dinosaur, all I need to do is look out my window and watch their descendants fly past.

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