One Mans
Stew
By Ed Lusch
Dinobirds
The
most universally accepted theory among scientists as to what led to
the extinction of the dinosaurs is an asteroid explosion of enormous
magnitude which fried, froze, starved and otherwise exterminated all
the dinosaur species living on earth 65 million years ago.
But
paleontologists are now saying, hold on, wait a minute... all the dinosaur
species were not killed off. One dino-representative survived and successfully
adapted to almost every niche on the planet—the birds. And if
your jaw hasn’t yet completely dropped open, that most terrifying
off all the behemoths—Tyrannosaurus Rex, wore feathers!
What
paleontologists know about dinosaurs has diminished exponentially over
the last 15 years. Science books up until the mid-’90s discussed
the distribution and classification of dinosaurs but little else was
known. Today’s textbooks will tell you what dinos ate, how they
behaved, locomoted, hunted and scavenged; the life history of these
mammoth creatures.
But
perhaps the most exciting theory (now proven fact) is that many dinosaur
species had feathers, including T-Rex himself. The dinos did not use
feathers for flight but for thermo-regulation (heat control) and later
evolved into primitive, non-flying birds, which, of course, eventually
took wing into flight.
How
did paleontologists discover that dinos, not birds, invented feathers?
Because of oxygen-depleted sediments on lake bottoms, a thin layer of
rock called paper shale formed about 135 million years ago. Paper shales
are excellent preservers of soft tissues such as flowers, hair, scales,
insect parts and feathers. Within this layer are fragments of dinosaur
bone with traces of a thin-film of dark streaks, a body covering of
unmistakably feathers, and, more specifically, T-Rex fossilized juveniles
have been unearthed in the last five years that are surrounded by feathers,
with some feather imprints still attached to the fossilized body.
There
are other defining characteristics linking dinosaurs to birds. Tyrannosaurs,
for instance, exhibit many of these similarities and recent fossil discoveries
bear this out; hollow bones, a wishbone, three primary toes, scaled
legs and feet and, as mentioned earlier, the undeniable evidence of
feathers.
It
is not known for certain why Tyrannosaur juveniles sported feathers
but the hypothesis is the feathers were needed for insulating small
bodies. A hatchling T-Rex weighed in at a meager three pounds. As they
grew to adulthood, up to 13,000 pounds, the feathers were shed; large
bodies hold more heat.
Were
birds flying around during the later stages of the dinosaurs? No, but
their near-prototypes were. Why and how the dinobirds evolved insulating
feathers into flight feathers constitutes a monumental debate among
paleontologists. Did front legs become feathered appendages advantageous
to balance and erratic locomotion for eluding predators? Then to long
jumping and gliding culminating eventually in flight? Yes, definitely
so, say some paleontologists. Not so, say others. But science does agree
that the development of flapping, feathery forelimbs in dinosaurs set
the evolutionary stage for birds.