Dr. Josh Samuels demonstrates how he removes a fossil from the rock to bring it into the lab for study. This fossil, discovered on 10/21/10, is the humerus (upper arm) of a Pogonodon, a jaguar-sized cat-like predator that lived 29-30 million years ago.
>> JOSH: All right what you can see here is a jacket of the Pogonodon humerus that Jennifer found yesterday
and what we basically had here was exposed the very top of the hummerus, the upper arm bone.
So the shoulder joint was up here and that has been removed, and we jacketed the rest of the bone
which extends down this way to the elbow joint right in here. Right above it here you can see the jaw
of a mouse deer, a hypertragulid. So we're going to be working to get that out. But the first thing we're
going to do is flip over this jacket, so we put it on there yesterday. It’s had a chance to dry and what I’m going
to be doing is chiseling down underneath it to loosen that up and then I’m going to pry it up.
[Sounds of rock scraping. Hammer hitting nail]
>> JOSH: You can see we basically kept the bone on this pedestal, jacketed it and now I’m just undercutting that
pedestal which is going to allow us to pry it up and flip the jacket over.
[Sound of hammer hitting nail]
>> JOSH: There we go… so the next step is we're going to bring this back to the lab and we're going to see is
Jennifer is going to slowly work on basically working down this rock using an air scribe, so that little miniature
jack hammer and she’s going to work this down to the layer of the bone and what we can see is the bone is running
along underneath here so there is quite a bit of rock here to remove, but that’s good we want rock around here
because it's acting as a protection it's helping to keep that fossil in tack as we get it back to the lab.
>> JOSH: So what we’re going to do is have Jennifer come back out and she’s going to be ah taking this and helping
cutting around here, basically cutting around, doing the same kind of thing, making a pedestal for this specimen we
will throw a very small little jacket on it and then take this off. You can see she already started cutting down
around this to make a pedestal. This is very hard rock so it’s going to take a bit of time.
Jennifer Cavin, fossil preparator, describes the process for preparing the Pogonodon humerus from episode one for study and display once it has been brought into the lab from the field.
>> JENNIFER: We just got this jacket in from the field. It’s the Pogonodon humerus that we took out yesterday and
the next step in the whole process is that the jacket comes into the lab where I will remove the rock from around
the fossil. So first I’m taking a fairly large air scribe and working my way down a little bit closer to the bone.
You still have to be careful because you never know when there might be another bone in there. But, a, basically
the bone is on the other side of this jacket, so I'm going to slowly take down all of this rock until I get down to
the jacket and then I going to go even slower and I’m going to remove some of the plaster from around it until I get
down to the bone. I’m going to glue any pieces together that need to be glued as I go along if the bone is falling
off and we use a polyvinyl acetate which is plastic dissolved in acetone as our glue.
[Sounds of air scribe]
>> JENNIFER: There’s a number of cracks that are running through the bone and you can see they're also running
pretty deep through the rock; so I’ll have to be gluing those up. Also I’ll have to, in the field the humeral head,
so the top half of the, um, of the bone had broken off already, so I need to re- attach that as well, its over
there. This is the proximal end of the humerus or the humeral head. This end would stick into your shoulder socket.
So that’s the shoulder part of the humerus and it broke off in the field. So after I get the jacket prepped down, so
that we can, the rest of the bone is exposed, I will take the rock off of this one and glue the ends back together
so we have a complete bone.
Jennifer Cavin, fossil preparator for John Day Fossil Beds National Monument, describes the process for completing preparation of the Pogonodon humerus from episode one.
>> JENNIFER: The last time you saw this fossil it was still completely covered in rock. After 40 hours of slowly
taking down the matrix you can see that the bone is now completely uncovered. The next step is to take it out of its
plaster jacket. I can tell already that there’s a large crack running all the way through the bone here so these two
pieces will probably definitely come off separately, and right here there’s a little bit of bone broken off, but
it’s okay if they break because the next step will be to glue it all back together. It’s a little stuck to the
toilet paper, but that’s easy to remove. Make sure to get all the little fragments.
[Sound of ripping]
>> JENNIFER: Okay, the next step will be to clean it up a little bit more and using a polyvinyl acetate glue, glue
the two pieces back together and then the original humeral head that was found in the field, that fell off in the
field will also be glued back on together, you can see we'll have a fairly complete bone.
[sound of light picking]
>>JENNIFER: I just spent the last four hours deep cleaning the bone a little bit more after we took it out of the
jacket. As you can see there are three pieces to the bone, the one break is a very, is a very clean break and the
pieces will fit right back together with no distortion at all. This is the break that was enclosed in the rock so
it’s a very clean break, the, a, the second break was the break that was exposed to the surface and as you can see
there’s just a lot of dirt still in there that contains some bone but to remove it you’d lose the bone, and a, so
this break I’m probably not going to be able to repair because there’s just some bone missing. As a size comparison
to the Pogonodon hummers you can see this modern cougar humerus that I’m holding here you can see it’s a much more
robust humerus on the pogonodon. Ok, now we're going to glue the good break back together. I’m using polyvinyl
acetate which is just a plastic polymer that’s dissolved in acetone. I apply the glue to one side of
the bone then I touch it to where it’s going to go to get glue on both sides of the bone, it creates a stronger bond
and then you wait till it dries. So a couple hours from now, at least, I’d say is when you want to handle the bone
next. Instead of holding it you can embed it in a sand box, this is one we kinda made here, and now we wait.
On July 30, 2011, park paleontologists teamed up with fire personnel from Malheur National Forest to airlift via helicopter a large, 28.8 million year old three-toed horse, called Miohippus, from the face of Sheep Rock.
>> JOSH: we will be removing this jacket, which contains a horse skull and part of a horse skeleton. What we’re
going to be doing is taking this jacket, rolling it onto the shelf, here we're going to be incasing the rest of it
in plaster and then working its way down the hill and the hopefully tomorrow will have a helicopter coming out and
they’ll be taking the jacket, loading it into that cargo net and air lifting it out.
>> JOSH: So now we’ve rolled the jacket over and you can see this lip wrapped around, where when they were
excavating it they had the jacket up on a pedestal, they undercut it a bit and then plastered underneath and this
lip helps to hold the rock in. And you can see it’s a nice flat surface and what Chris is going to do is put some
toilet paper on there, soaked with water and spreads it across this surface. It’s going to add a little bit of
padding, then we're going to put more plaster and burlap over this and then we basically have the fossil enclosed in
an egg made out of plaster and burlap. It will keep it safe and it will keep any of the rock and fossil from falling
out when it’s getting air lifted. So Matt is taking a strip of burlap and he’s putting it in our plaster and then
we're going to use that strip of burlap soaked in plaster, we're going to be applying it over where we put the
toilet paper previously and what we’re going to do is basically stretch out these strips. We want to make sure that
they over lap and we're just going to gently smooth them down. And we're going to be spreading this plaster across
the strips to help hold them together and give them strength.
[Sounds of helicopter]
[Sounds of helicopter]
[Sounds of helicopter in distance]
[Sounds of helicopter]
>> JENNIFER: Look at thaT.
>> Man: Nice work.
>> JENNIFER: yeah!
>> JOSH: ExcellenT. Thank you.
>> JENNIFER: Perfect.
>> MAN: You bet.