So we are here in Oversized Geology, surrounded by dinosaurs
and any other prehistoric life that is too big to go anywhere else in the museum.
And we are here with Joyce Havstad,
who quite possibly has a job title almost as great as mine.
What is your role here at the Field Museum?
People are here call me the Philosopher in Residence.
All knowledge must come through the senses.
At the Field Museum, what are some of the concepts or ideas you have pursued
in your post doctoral residency here?
Holotypes
Holotypes are the individual physical specimens
that bares the name for and acts as the exemplar of a species as a whole.
It's the basis, the gold standard, for a...
Yeah, it's the universal standard.
It's the yard stick that you measure up other organisms
that you think might belong to that species
and you see whether they match or not.
So is seams to make a lot of sense, and it would be really easy
with a massive library and millions of comparable specimens
if you find something existing today.
But what do you do in the case of the fossil record,
where you might not have a complete skeleton of something,
how do you know if it's a new species or not?
Do you know about the meter bar?
Back when science was just getting off the ground,
the guys doing science realized
we needed a universal standard of measurement.
We needed a distance we could all agree on.
That was the meter.
They argued how long a meter should be.
Eventually they decided it would be
one ten-millionth of the distance between the equator and the North Pole.
So then they had to figure out how long that distance was.
What's one ten-millionth of the distance between the equator and the North Pole?
So they sent some guys out who spent almost ten years measuring
the distance between this belfry in Dunkirk and a castle in Catalonia.
But eventually everyone realized that
we needed an official bar.
that was like the prototype meter.
1889 they made a bar,
of 90% platinum and 10% iridium
and they put two lines on it
and keep it at the temperature of melting ice.
The distance between those two lines on the bar,
at that temperature, is a meter.
Okay so you asked about paleontology.
Now imagine,
if when a science wanted to know
how long is a meter?
And someone was like "Okay, it's right there."
But they only had bits and pieces of the meter stick.
It had been like chunked up, it was missing and had been thrown all over the room.
That's the kind of situation that paleontologists are dealing with when
they are trying to point to and figure out
what's the specimen that represents an entire species, like Brachiosaurus.
We are standing in the holotype of Brachiosaurus.
It was declared the largest dinosaur known when it was discovered,
on the Fourth of July in 1900 by Elmer Riggs, Field Museum scientist.
So, Brachiosaurus
What do we have of it?
We have seven vertebrae,
the Sacrum,
two caudals,
four dorsal ribs,
coracoid,
hurmorus,
ilium and femur
And this is the femur?
This is the femur.
So what is that like fourteen bones of the brachiosaurus?
It's about twenty percent of the whole skeleton.
It's still the most complete brachiosaurus specimen we have.
Can you image what Elmer Riggs what thinking
when he uncovered this sort of thing?
Is his first thought like, "I have discovered a new species?"
What do you think when through his head?
And then afterwards, how did he determine that this was the holotype of a brand new species?
One of the things about the brachiosaurus
that's really interesting
and that was difinitive for Riggs
in thinking that this was a unique sauropod.
A huge, gigantic, unique sauropod.
Is a bit of information that we get from the fact
that we have the femur and the humorus.
So look at this humor,
it's huge and it's long.
But guess what?
The humorus is even longer then the femur.
The humorus is longer.
So it kind of had a like... it was a little short in the back.
Yes, now think about what other animals that looks like.
That's a great question.
With the shorter legs and the longer arms.
That would tilt you up, right?
So like normal sauropods, with the...
Like a giraffe.
-Like a giraffe! -Like a giraffe!
The other species, the most closely related species, to brachiosaurus
are actually named after the giraffe.
It showed that this wasn't like evenly balanced, it was the titled back long neck.
That tells us about ecology as well.
Likely to be feeding on foliage from trees
and not necessarily grazing on grass.
There is just so much we can learn from the ratio between the femur and humorus.
Oh! Okay
No, that's really, I'm impressed with how I drew that conclusion.
Awe, I was right.
Not that I accomplished anything.
I think that's a really exciting way to look at just a little bit of information
and being able to infer as much as possible
by critically looking at the small bits and pieces that you have.
That's whats going on.
It's the sort of detective work that paleontologists are doing even the partial skeletons.
And then working with these holotypes.
That's the kind of characteristic feature that would make someone have a good solid argument, like Riggs.
Give him a good argument for thinking, this is it's own unique species, this is a holotype.
I've discovered a new species
and it's the largest dinosaur ever.
I bet you felt good at the end of that day.
Yeah, I was pretty psyched I think.
It still has brains on it.