(gentle orchestral music)
- It's been about 65 million years,
give or take a few,
since an asteroid slammed into earth,
most likely,
and caused the mass extinction
that killed the dinosaurs off,
which means there's a pretty gulf of time
between when the dinosaurs lived
and our present time.
And yet, we feel pretty confident,
apparently, that we can walk around
and draw pictures of
dinosaurs all day long.
But have you ever wondered
how we know what dinosaurs looked like?
It turns out that we make a lot of guesses
and we make those guesses,
well not me,
but paleontologist, scientists,
humans like me, from fossils.
Fossils are the remains of dinosaurs
or other animals
where the bone,
the biological material
that makes up the bone,
is slowly replaced with minerals
and other hard materials
so that the bone literally becomes rock.
And if you take all these fossils,
all the fossils in the
world that we've ever dug up
and put them together,
you have what's called the fossil record.
You can think of the fossil record
as pieces of a jigsaw puzzle.
We're missing a lot of
stuff in the middle,
but the fossil record
makes up the puzzle edges
and that's a pretty good place to start.
And the places we do
start are with the bones.
For example, just how bones fit together
tell us a tremendous amount about
how dinosaurs moved and
stood and hung around.
Teeth tell us whether a
dinosaur was a carnivore like
with sharp pointy teeth
or was a vegetarian,
because they have flat leaf-shaped teeth.
And depressions in the skull show us just
how well a dinosaur could see or hear.
But these are just bones though, right?
True.
But in some instances,
paleontologists have
really, really lucked up.
For example, in North Dakota in 1999,
a paleontologist named
Tyler Lyson found the edmontosaurus
not only with the bones intact,
but also some tissue fossilized.
From this, CT scans have been taken
and we've learned a treasure trove
of information about dinosaurs.
For example, feathers.
It's true.
Not all dinosaurs were scaly creatures.
Some had hair-like filaments,
kind of like a pig,
others had feathers.
And we know this,
thanks to things called quill barb marks,
which were little depressions in the bone
where the feathers would connect.
Not all paleontologists are comfortable
with calling these things feathers.
Some like to call them
augmentary structures or protofeathers.
Whatever.
These dinosaurs,
including some very famous
ones like velociraptor,
had something that you
would call a feather.
Even more astounding,
these feathers appear to have
been pretty colorful too.
In 2012, paleontologists
did a scan of a microraptor
and found something called melanosomes,
little tiny structures in
a cell that hold pigment,
kind of like what gives your hair pigment.
These melanosomes found
on this microraptor indicate
that the feathers were iridescent,
which would have looked pretty awesome
when the thing is coming at you
to tear your throat out.
Considering that
paleontologists are working
literally with just piles of bones,
the evidence they've come up with
and the ideas that they've made
about what dinosaurs look
like is pretty impressive.
Are you impressed with dinosaurs?
We want to know all
about your dinosaur love.
Leave them in the comments below.
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