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Sauropod dinosaurs – the ones with the really long necks –
are some of the most famous and instantly recognizable of all ancient animals.
Their most outstanding feature has got to be those incredible necks.
These included the very longest necks in Earth history,
with some growing more than 12 meters long!
So with this being one of the most iconic features in all of evolution,
you’d think we would know what it did.
And…you’d be wrong.
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If you look at dinosaurs in books and movies,
you’ll see that those necks have been depicted in many ways over the decades.
Sometimes they’re held straight upward from the body, sometimes straight
out front, and sometimes they’re all wiggly like a cartoon snake.
And here’s the fascinating thing: we don’t know which way is correct.
Well, it’s probably not the wiggly cartoon version.
But paleontologists have been debating over sauropod neck posture for decades.
It’s a surprisingly hard question to answer.
It’s not as easy as just putting the bones together and seeing how they fit.
For one thing, we have almost no complete sauropod necks.
Even the best-preserved sauropod skeletons
are usually missing a few neck vertebrae.
This is partly because they’re just so darned big.
To get a fossil you generally need the body to be buried quickly,
and with something that big it’s just not likely to happen to the whole thing.
Another problem is that we’re also missing soft tissue –
cartilage, tendons, ligaments, the kind of stuff that doesn’t often fossilize.
And these are key factors in the flexibility and length of an animal’s neck.
Plus, strange as it sounds, the neck might not be the only important part
of understanding the posture of… the neck.
Some researchers have examined the shape of the dinosaurs’ inner ears,
which can help us understand how they held and moved their skulls atop their necks.
And others have estimated the position of sauropod shoulders and hips.
Tall shoulders, for example, might have been key for providing support
for lifting the long neck.
And on top of all that, it can be really hard to tell the difference
between what an ancient animal could do, versus what it did do.
Like, if you looked at my skeleton, you might say,
this person was fully capable of going for a ten-mile run every morning.
But I don’t do that.
Because I don’t want to.
So, with all this in mind, you can start to see why this question
has been debated so much: we’re working with limited information.
But there’s another thing you might be wondering:
why do we care so much how these dinosaurs held their necks anyway?
Well, for one thing, it’s just plain fascinating.
Some published estimates suggest that if these dinosaurs
could hold their necks vertically, some species might have
been able to raise their heads twenty meters in the air standing on their tippy-toes.
If that’s true, that’s awesome.
So, we want to know if it’s true!
But besides that, our interpretation of sauropod neck posture
also affects our understanding of how they used them.
Sauropods were the biggest animals in just about any ecosystem they lived in.
And like any large animals,
they would have had a huge impact on the environment.
The better we understand what they were doing,
the better we’ll understand how their entire ecosystems functioned.
Two main factors are thought to have driven the evolution
of these super-long necks: food and sex.
On the one hand, long necks are obviously good for accessing food,
but different neck postures are good for different diets.
A tall neck would be great for reaching high plants
that no other herbivores could access.
While a horizontal neck might be good for quickly and efficiently
sweeping a whole area of low vegetation.
It might seem like a simple distinction,
but it has all sorts of implications for the lifestyles of these dinosaurs.
The quality of their food, and their ease of access,
would affect how much they had to eat, how far they had to wander to find food,
how well they helped plants disperse, and more.
That’s a lot of valuable information that comes down, in part, to neck posture.
And then on the other hand, extraordinary structures in evolution
often function as tools for attracting mates and intimidating rivals.
Long-necked animals today often use those necks for showy displays,
courtship rituals, or even for fighting rivals.
If we understood what sauropods were doing with their necks, it could help us
better understand how they interacted with each other, whether they waved their
necks slowly during courtship or violently smashed them together like giraffes.
Seriously, just watch a pair of giraffes fighting sometime.
It’s terrifying.
And it’s also ridiculous.
And just to complicate the whole thing, there probably isn’t a single correct answer.
More likely, there are many.
Sauropod dinosaurs were extremely diverse.
There were loads of species living in habitats all over the world
for over a hundred million years.
The answers to these neck questions might be as numerous and diverse
as the dinosaurs themselves.
So, for now, the debate is far from over.
But the more we explore this topic, and the more we analyze the amazing anatomy
of dinosaurs, the more we understand about the ancient world…
even if there are some things we might never know.
It’s easy to get stuck in a single train of thought that supports
your original hypothesis, like the idea that long necks are also tall necks.
But good scientists are able to keep an open mind
and let the data tell them how the world works.
That’s the whole idea behind hypothesis testing,
which you can learn all about in the Brilliant course dedicated to the topic.
This course teaches you how to use the power of statistics when testing
a hypothesis, proving a point, and understanding the world around you…
or the way the world used to be.
You can unlock all of those answers with a great dataset and the stats
in this course, from making sure your sample size has enough power
to running a linear regression that helps you analyze your results.
And Brilliant will show you how.
Brilliant is an online learning platform with thousands of lessons in math,
science, and computer science available when you type Brilliant.org/SciShow
into your search bar or go to the link in the description down below.
That link also gives you a free 30-day trial and 20% off
an annual premium Brilliant subscription.
Thanks to Brilliant for supporting this SciShow video!
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