Monday, December 8, 2008

The Survival of the Dinosaurs - Chunk 1

When I was five years old, I was taught that dinosaurs had all died off, so there was no chance that I could ever see what they were like.
` If only I had known that real live dinosaurs lived in my own house, remnants of a lineage that had survived the great dinosaur extinction, I might have seen my pet birds in a very different way.

I remember how my grandma would cautiously peek through the front door before entering, with the question; "Is that robin in his cage?"
` Robby might have just as well been a ferocious meat-eating dinosaur as far as she was concerned - and he as well, judging by the way he gave chase.

It is with great irony that I later learned this isn't far from what all the scientific discoveries show; Robby's own grandparents, ones living way back in the Early Jurassic, actually were ferocious meat-eating dinosaurs!
` Technically, robins are but a 'new' species of dinosaur.

The idea that birds are but a branch on the dinosaur family tree was once controversial; however, after many decades of meticulous research and hundreds of amazingly well-preserved fossil finds, there is no longer much room for doubt.

I could go on, into great detail - so, where to begin?


Which Dinosaurs Are Birds Related To?

Over a century and a half has gone by since Thomas Henry Huxley recognized that birds have much in common with dinosaurs - and in particular, a group of meat-eaters with the strangely-spelled name of Coelurosaurs.
` The word is pronounced "see LOO-row saurs" and means "hollow reptiles", in reference to the air-filled sacs preserved in their bones. These air sacs are similar to the ones found in birds, and seem to have been connected to the lungs in a similar way.


Am I supposed to know what Coelurosaurs are?

If you've heard of Tyrannosaurus rex, then you know at least one! Undoubtedly, this is the most familiar coelurosaur species, though it is also among the most unusual:
` Whereas most coelurosaurs are rather small, with long, well-developed arms, you will know that Tyrannosaurus was huge and heavy, with short, stubby arms and massive jaws.

You might also be familiar with Velociraptor, made popular by the movie Jurassic Park, although it was much smaller in real life.
` Important to know about Velociraptor is the fact that it belongs to the dromaeosaur (DRO-mee-o saur) family.
` Four noticeable features of dromaeosaurs are 1.) the single, retractile sickle-shaped claw on each foot, 2.) long arms that could 'flap' like a bird's wings, 3.) opposable fingers, and 4.) reduced and fused tail bones, resulting in a stiff, rod-like tail.
` Though Velociraptor's skin has never been found, other dromaeosaurs are known to have had feathers almost exactly like those of adult birds, differing only in the complexity of microscopic hooks.


Why Are You Telling Me This?

Because, another famous coelurosaur is precisely what you'd expect if the fearsome Velociraptor had a smaller cousin that could fly.
` Known from several well-preserved specimens, the first few having been discovered in the 1800s, it has another strangely-spelled name; Archaeopteryx (say; "arkee OP-ta-ricks").

Though it was among the earliest birds known, Archaeopteryx - and its close kin - resembled the dromaeosaurs far more than they resembled any bird living today.
` Though its well-preserved feathers were identical to those of modern birds, Archaeopteryx had teeth similar to those of dromaeosaurs, as well as a fused, stiffened tail, grasping hands, and a sickle-shaped retractile claw, among many other characteristics.

In fact, one Archaeopteryx specimen with very poorly-preserved feathers had been thought - for a whole century - to be another tiny coelurosaur called Compsognathus (comp-sog NAY-thuss) until Dr. Peter Wellnhofer noticed the feathers in 1993.


So, when are you going into great detail about all this?


It starts in Chunk 2!

2 comments:

Galtron said...

Is leaving people hanging in suspense part of your dastardly plot to take over the world?

S E E Quine said...

Maybe.