Wednesday, February 4, 2009

Dinosaur Reconstructions

We see best when a window is clean and when it comes to visualizing the past the more information we have the clearer and more accurate our view.

The extraction and preparation of fossils has improved ten-fold from the early beginnings of paleontology. As a teenage my heroes were Charles R Knight, the painter of majestic prehistoric murals, and paleontologists Colbert and Osborne, who patiently studied the cryptic bones extracted from ancient rock. In this dawn of paleontology fossil bones were blasted, teased, or brushed from the rock holding them, slathered in protective rice paper, burlap and plaster and hauled off to museums to be mounted like trophies. With time, fortunately, these recovery and investigative techniques have grown much more sophisticated. Now we know the stony matrix has its own story to tell about the environment where the entombed fossil lived. Pollen grains identify contemporary plants. Fine textured or clayey stone can hint at skin texture, fur or feathers, allowing us to better determine what the fossilized creature was like. And what discoveries have been made in China in just the last decade! Hordes of unhatched and fossilized eggs. Details of skin and appearance that would never had been guessed at years before. Who would have thought these scrambling “reptilian monsters” would have feathered fans on their arms and legs to better flee predators or chase down prey. Who would have suspected that T-Rex hatched out as a downy chick! These new fossils from China have precipitated a renaissance in dinosaur science and understanding.

Below is one of my favorite drawings by Charles R. Knight of an Ornitholestes. The reconstruction was based on the best fossil information of that period. It’s shown as a nimble, active, fleet of foot catcher of birds (itself a daring and radical idea at that time).

Now check out the 2008 painting by Peter Schouten of Ornitholestes hermanni as reconstructed from imprints and bones from the fossil beds of China. Still fleet and nimble, Ornitholestes is now feathered rather than scaled, and arboreal! Although the coloration and patterning is speculative, if we were to see this creature in the wild today it’s highly unlikely we would now mistake it for a prehistoric variant of six-foot lizard.

But for an asteroid and runaway volcanic eruptions in India, dinosaurs might still be dominant today (bad for us), but smarter and more complex undoubtedly. Slain by catastrophe 65 million years ago, a unique alien world vanished with these fascinating creatures. But our window into their lives is becoming less murky as better extraction techniques and CT scans and rare fossil mummies enrich our view. We should have more respect for the budgie by the window – it’s relatives once dined on triceratops.

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