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Thursday, September 15, 2011

Interlude: Dinosaurs and their Feathers

If there's one thing I like more than birds, it's dinosaurs. Big, lumbering, small, graceful, dinosaurs came in all shapes and sizes. The largest is somewhat debatable - Argentinosaurus is the biggest we have good data on (it was somewhere in the range of 100+ feet, and quite massive), but if the bones of Amphicoelias hadn't been lost, we'd be looking at a 200-foot behemoth! The smallest dinosaur, however, we can know for sure. Discovered almost 160 years ago, it's the little 2-inch long Mellisuga helenae - the Bee Hummingbird.

You're looking at one of the most ferocious predators of all time!
Photo from TripAdvisor.

That's right, birds are dinosaurs, albeit highly evolved ones. They're a direct descendant of the dinosaurs in Maniraptoriformes, better known to the layman as the raptors. Most people would consider Archaeopteryx to be the oldest known bird, but in fact it's just another dinosaur, an advanced Deinonychosaurid closely related to the Troodontidae and Dromaeosauridae (Xu et al., 2011). Even the famous Velociraptor has been shown to have quill knobs on its arms, a tell-tale sign of flight feathers (or something akin to that). To recap - Birds are dinosaurs. Archaeopteryx is a dinosaur. But Archaeopteryx is not a bird.

Not visible in this picture - the hyperextensible second toe, better known
as the "raptor claw", which Archaeopteryx is now know to possess.
Photo from Wikipedia.

To have feathers does not necessarily make you a bird. Until the 1990s, Archaeopteryx was the only known dinosaur fossil with preserved feathers (of course, remember everybody thought that fact made it a bird). Since then, feathered dinosaur fossils have been flooding in from China, most showing primitive filamentous feathers, although more than a couple show vaned feathers that could make them capable of flight. However, these fossils are just the impressions of feathers, an imprint of an animal that died in favorable sediment. You can't walk down the street and pick up a dinosaur feather like you can a discarded bird feather. Or, you couldn't. That is, until today.

Say whaaaaat?!
Photo from The Atlantic via Science.

In the journal Science, researchers reported specimens of amber from Alberta that date to around 80-million years ago (you may note that non-avian dinosaurs still had another 15-million years to go on the Earth). Some of the amber showed what are clearly vaned bird feathers, but others show the trademark filamentous feathers of dinosaurs. Just how the feathers became trapped in the amber, I'm not sure, but the fact remains - we as a world community are now in the possession of real, honest-to-God dinosaur feathers. Now if we can just find an eccentric old Scotsman to pony up the cash and clone these bad boys.

2 comments:

  1. Wow, interesting stuff Robert! The feathers are so cool.

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  2. @Jeremy - Thanks! Might do more dinosaur-related posts in the future, depends on how well I can tie in the bird aspect.

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