Hidden inside this unassuming piece of limestone are the remnants of a creature that reveals
an extraordinary link between the age of dinosaurs and the present day.
Meet the wonderchicken.
- All of a sudden we saw this incredible skull staring out at us, once we caught our breath
and actually took a close look we realized that some structures of the skull, were very
similar to what you see in living chicken-like birds.
And so the name "wonderchicken" just materialized then and there.
The wonderchicken isn’t just a well-preserved fossil; it’s also a missing piece to the
puzzle of how modern birds came to be.
And this discovery might just change everything we thought we knew about their dino-heritage.
Again.
It all starts some 66 million years ago, when we think a meteorite or comet hit Earth and
wiped out the dinosaurs, bringing an end to the Cretaceous period.
That moment in time is now permanently marked in our geological record by a thin layer of
rock referred to as the K-T boundary.
- And within that clay you see a geochemical signature of a giant space rock hitting the
earth.
We have scant fossil evidence of birds from the Cretaceous period (you know, around the
time a giant space rock hit the Earth), which is why it's incredible to think that when
an amateur fossil hunter picked up this hunk of rock near the border of Netherlands and
Belgium, it sat unexamined in the back of a Dutch museum for twenty years.
But this year, Daniel and his team used Computed Tomography, a kind of x-ray sampling that
rotates around a sample to create cross-sectional, 3D images without damaging it, to take a more
detailed look.
- It was amazing, right at the outset we discovered that these not-very-pretty fossils
were actually much more important than they initially appeared.
So, what can the wonderchicken’s skull tell us about the era of the asteroid and the origin
of pigeons… and other modern birds?
The first clue is that frontal bone in pink.
Equivalent to the forehead bone in you and me, this bone's hourglass shape suggests a
similarity in form, and maybe function, to modern-day ducks.
And that yellow bone connected to it is the nasal bone.
- The shape of the nasal bones are very interesting because their general profile and architecture
are very similar to what we see in living relatives of chickens.
And, in the turkey skull, if you can see, this bone here bounding the back of the nostril
is the nasal.
The general shape and architecture is very similar.
Finally, the dead ringer is the bone in red, called the premaxilla.
- The fact that the beak is very prominent and it's composed entirely of the premaxilla
tells us that yes, this is a modern bird.
It's been thought that the birds that exist today descended from early ancestors that
somehow managed to survive the Cretaceous-Tertiary extinction event.
But up until now, we hadn't found much clear evidence that modern birds and dinosaurs
like T. rex and Triceratops coexisted.
- The fact that we have a modern bird from just before this asteroid struck the earth
and wiped out the giant dinosaurs tells us that the earliest stages of modern bird evolutionary
history overlapped with the very final stages of the giant dinosaurs occupying the Earth.
So how did this little guy survive the mass extinction, while his enormous compatriots
were wiped out?
Well, we don’t quite know for sure.
But it could be that the wonderchicken's small size saved its life.
This phenomenon is called the Lilliput Effect, which states that smaller-bodied species which
have lower total metabolic requirements are more likely to survive harsh conditions.
It also helps not to be too picky of an eater.
- If you think of a normal barnyard chicken, they will be generally pretty happy to eat
almost anything that's put in front of [them].
It has a generalist diet that may have made organisms perhaps better-suited to surviving
the mass extinction event than organisms with highly specialized diets.
But for Daniel and his team, this amazing discovery might just spin up more questions
than answers.
- What kind of birds actually managed to survive the extinction event that wiped out the giant
dinosaurs?
Were birds actually rare for a period of time after that extinction event?
We're hopeful that we'll be able to shed more light on these questions by finding new fossil
evidence of birds from these periods of time.
Fun fact: based on its long, narrow hind limbs, the scientists think that this wonderchicken
may have been a shorebird.
So, the researchers gave the new species the genus name "Asteriornis," after the Greek
goddess of falling stars, who transformed herself into a quail and threw herself into
the ocean to escape an amorous Zeus.
For more on dinosaur history, check out this episode here.
If you have any other prehistoric science you want us to cover, let us know in the comments
below.
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