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Yvonne_Wilson
posted 08-02-2002 10:59 AM
Juvenile
Rhino Radius and Ulna
These
two bones are considered to be from a juvenile because the ends
are still unfused as seen by the rugose or roughened ends. Similar
to humans, the bones of other mammals fuse when they reach adulthood.
Yvonne_Wilson
07-24-2002 01:05 PM
Courtney's
mishmash of bones is well on its way. Much of the matrix has been
completely revomed. She got some help from Jason, another intern,
and a couple volunteers, so the work went quicker. Not too much
left to go...
Yvonne_Wilson
07-03-2002 11:48 AM
Carol got the femur together with its counterpart from the other
jacket. She also plastered the cracks in all the bones. Here are
some final shots:
Yvonne_Wilson
07-03-2002 11:39 AM
We
received a skull from our research associate which had already
been largely removed from the matrix, but still needs a good deal
of work. The front teeth are detached, and must be cleaned and
reattached. There is also a thin veneer of dirt that must be removed
from the entire specimen. Take a look:
This
is the new skull beside the finished one we did in the lab previously.
Carol
has what should be a nice specimen when she is done.
Yvonne_Wilson
07-02-2002 11:06 AM
Courtney
opened a jacket labelled "Ribs Etc".
We
now know what the "etc." means. She found a forearm (radius and
ulna), as well as 18 rib sections and 3 vertebrae. Compared to
the ribs and vertebrae, the limb bones are in good shape. Here's
a picture:
The
dust is making Courtney sneeze all the time. But that hasn't deterred
her efforts. We have a serious crew of preparators here!
Yvonne_Wilson
05-15-2002 04:05 PM
Carol
is puzzling the last pieces of femur together. Shw will then plaster
the cracks and holes. Eventually she will join the end of the
femur from her jacket to the half that came out from my jacket
with the rhino hips. Stay tuned...
Yvonne_Wilson
posted 04-25-2002 05:41 PM
Carol
has the rhino foot exposed now. It's quite lovely for this material.
The foot and lower limb is nicely articulated (the bones are placed
where they were in life). Here's a photo:
Yvonne_Wilson
03-14-2002
12:41 PM
She's
got toes showing. Three stubby rhino toes made their appearance.
Next
Carol has a challenge. The rest of the femur has most of its parts,
but the bones shifted before they were glued together. She had
to drip the glue on them before she even touched them or they
would have crumbled all to bits. Now it is a matter of either
breaking them apart, or if possible, working off the glue connections
by dissolving them in alcohol. She says she is not looking forward
to the job.
Yvonne_Wilson
02-28-2002
04:08 PM
Carol
is working on parts of the same rhino whose hips drove me crazy
for so long. She has the end of the femur (thigh bone) that didn't
make it into the other jacket, a lower leg and foot.
If
you look at the lower leg of this critter, you would swear it
was a dwarf. It has a regular sized femur but a stumpy little
shin. Imagine your shin being half as long as it is now. Those
are about his proportions. We'll have to look into this to see
if it's a funny individual or some type we haven't seen before.
He sure is bizarre!
Yvonne_Wilson
02-21-2002
08:03 PM
The large flat plaster jacket on the center table has a mess of
ribs crossing over one another. There was a warning written on
the jacket that it would be tough, but it has turned out to be
one of the faster and easier rib projects. We numbered the ribs
and made a diagram of what came from where to keep it all straight.
But it is largely complete, with only some gluing to finish.
Yvonne_Wilson
01-17-2002
05:22 PM
This
rhino project is done now. I plastered a board to the base of
the jacket to support it. I can help it no more. Bill Korth, the
reseach associate who collected the rhino material, brought in
the other half of the femur. It was taken out of the rock in a
separate jacket. Sometime soon we will have a complete femur for
our collection. Goodbye rhino, I'm off to work the dinosaurs.
Yvonne_Wilson
01-13-2002
01:16 PM
AAK!
I was trying to reinforce the jacket just before finishing this
up today. Michael and I lifted the jacket up onto a board...the
entire jacket flexed and broke up parts of both the pelvis and
where the spine and pelvis meet! The bottom of the jacket without
the rock in it is like a piece of cloth: there's no strength in
it whatsoever. I found another downward projecting part of the
jacket that is that soft too. I want to scream! I was going to
finish today...ARRRRGH!!
On
a calmer note, I smeared plaster all into the cracks in the femur
and it seems solid and happy. At least somebody is!
Yvonne_Wilson
01-06-2002
12:57 PM
We
keep opening up more and more jackets containing ribs. Some of
them are purely plant food, with roots snaking all the way through
and into the bones.
Yvonne_Wilson
01-06-2002
12:48 PM
Barbara
also has a jacket with vertebrae in it. These were jumbled like
puzzle pieces, however. At first we couldn't even figure out what
portion of the spine we were looking at, but then we realized
what we were seeing was not one but two bones intertwined. Oops!
Yvonne_Wilson
01-06-2002
12:41 PM
Getting
into the "base" of the concretion on the spine, I'm finding a
few preserved vertebral surfaces here and there. The weird part
is that those preserved surfaces were closer to the ground surface.
This rock is so highly variable - the fossils seem almost randomly
permineralized (preserved with minerals taken up from the surrounding
rock) or leached of their own minerals.
I'll
do a little more final clean up and then reinforce the jacket
for storing in the permanent collection. Then it's time for a
new project!
Yvonne_Wilson
12-30-2001
04:19 PM
Diane
worked on a right scapula (shoulder blade) that was very cracked
and infiltrated with plant life. The roots grew in among the cracks
pretty thickly. Despite a fair amount of deterioration, she was
able to salvage a good portion of the specimen. It was a good
example of our rhino material. Diane's almost done with the project.
All she has to do is some undercutting and then the back side
of the scapula will be free.
Yvonne_Wilson
12-27-2001
10:12 AM
The
femur was deceptively solid-looking at first. The end of the bone
collapsed and crumbled. The ball joint, however, isn't doing too
badly. Michael should be done with this piece relatively soon.
Yvonne_Wilson
12-26-2001
10:20 AM
Getting
down into that concretion, I'm finding lots of "spine" but it
has no surface -- it is unconsolidated powdered/crushed bone material
in roughly the space the spine should be. Arrgh!
Yvonne_Wilson
12-19-2001
11:04 AM
Within
my ugly concretion, what I thought was going to be a vertebra
ended up being the head of a rib (another rib!). Unfortunately,
it looks like the best information we could get from this jacket
would be how big a baby rhino could get.
Forrest
Gump might say, "Fossils are like a box of chocolates..." We have
to go through all the jackets to be sure we aren't missing anything
new or important.
Yvonne_Wilson
12-14-2001
10:22 AM
A
cool surprise -- Carol found a pretty wrist bone in with her hip.
It's about as long as a baseball is wide. This rhino was no demure
little creature, that's for sure!
Yvonne_Wilson
12-14-2001
10:17 AM
Despite
nasty technical difficulties (the compressed air line was spewing
lubricating oil and condensed water), I uncovered what looks like
the end of the pelvis. It was warped up and a large chunk is missing
where that big crack was when I first opened the jacket. Mother
Nature was trying to recycle this critter, grinding him into dust.
Nature is terribly efficient at that and that's why fossils are
so rarely preserved. She got to the spine before I did -- it is
not much more than crumbly powder encased in concretion.
So
what remains is to take this concretion down, cut the jacket to
fit just the pelvis, clean it up a bit more, reinforce the jacket,
and this project should be done.
Yvonne_Wilson
12-07-2001
12:29 PM
Why
are the bones so broken up, you ask? This pelvis, in particular,
has lots of roots of plants emerging from the cracks. Plants can
break up brittle bone fairly easily. The bone is softer than the
encasing rock, so the roots take the easier path growing through
the bone. End result: broken up fossil.
I'm
very close to taking the femur our of the jacket. It's just a
matter of gluing it sufficiently to hold itself together. But
it will be very soon...
Yvonne_Wilson
12-04-2001
04:59 PM
For
some reason, there are lots and lots of ribs preserved in these
specimens. Yes, each critter had many ribs, but they are easily
broken and less likely to be preserved than larger, sturdier bones.
We
have a few people working on jackets with ribs in them. Some are
nearly whole, while others are fragmented.
Yvonne_Wilson
12-04-2001
04:55 PM
Considering
the lower surfaces of these bones are so highly fractured, I really
wonder what the top surfaces look like. (I am working this jacket
from bottom to top.) Usually the top is in worse shape because
it gets more exposure to the weather and to local critters. I
hope that these are atypical and the tops are in better shape
than the bottoms.
The
lower surfaces of the vertebrae have not been preserved well at
all. The bone is powdery and crumbled. There really isn't anything
in those vertebrae to save thus far. But I have to keep working
out the matrix in case there is something cool behind it. You
can get lucky when you least expect it.
Yvonne_Wilson
11-30-2001
04:55 PM
That
supposed "knee cap" turned out to be the end of a limb bone. I
have been doing more detailed cleaning of what is exposed so far,
so it may not look like I've made too much progress. It's just
that the work now is nose-to-the-fossil style.
Yvonne_Wilson
11-28-2001
05:01 PM
Ugh!
Part of the pelvis is so broken it's see-through! Glue and crossed
fingers are my tools today.
I
found yet another rib and a lump that might (?) be the knee cap.
Perhaps. Sometimes you just can't tell until you can see the whole
thing. I can't see if it is the broken end of a long bone or if
it is complete as is.
Yvonne_Wilson
11-28-2001
04:54 PM
The
hip is now uncovered and is in lovely shape compared to the other
rhino material we're working. The ribs broke up a bit, but we
have many ribs and just a few hips (Hip hip hooray!)
Yvonne_Wilson
11-25-2001
05:20 PM
Diane
has been working on a small jacket which contains at least 6 rhino
vertebrae (backbones) still hooked together. Vertebrae have lots
of projecting spines and flanges so they can be very tough to
work on. All the projections tend to break off. Her jacket is
even more difficult because the bone is mostly encased in the
really tough concretion portion of the matrix these rhinos are
coming from. It's not only very hard, but it sticks to the bone
better than the bone sticks to itself. Often the bone will split
down the middle, half adhering to each side of the rock. Nasty
stuff to work in. Not surprisingly, the vertebrae are coming out
a bit unhappy. She may have to leave the back half of the spine
in the rock in the jacket. Sometimes it's just safer that way.
Yvonne_Wilson
11-25-2001
05:09 PM
Wow!
Bone everywhere! This weekend I took about 100 pounds of rock
out of the jacket. I uncovered the blade of the pelvis, more of
the previously found pelvic bone, ribs floating about everywhere,
and the leg bone which is now mostly out of the rock. It's all
so crumbly, though. The bone is highly fractured and in some places
just disintegrates into powder. It's good to see so much bone,
but sometimes you just want to be able to get straight at a particular
piece you are working on, not have to stop and work out the many
small pieces in the way. And why o why can't the bone stay together?
Yvonne_Wilson
11-21-2001
04:49 PM
Carol
has another rhino jacket to work on. In the field they labeled
it "Half Hip." It seems to have some extra goodies in it too.
She uncovered part of the hip, a rib, and what may be a limb bone.
It's a Rhino Smorgasbord
Yvonne_Wilson
11-21-2001
04:43 PM
Dirt,
dirt, and more dirt...
Today
was fairly uninteresting, as some days are. I was trying to even
out the surface of the open jacket. I took off a lot of matrix,
but didn't uncover any new surprises. Twice I thought I hit bone
but the pieces were just floating scraps no bigger than a pebble.
My brand new air scribe died too. Stinky day for rhinos, I suppose.
Don't
forget that the turkey you eat tomorrow on Thanksgiving is a dinosaur
descendent. Mmm, roasted dinosaur!
Yvonne_Wilson
11-21-2001
10:28 AM
When
I opened the hip/spine jacket, there were two pieces of bone showing.
One was a scrappy long bone, broken off after about an inch, but
you could clearly see where the rest had lain in the rock (the
outline was still there). Too bad the bone itself isn't present.
The other piece is part of the femur, a bit broken up, but still
probably useful for study. I should make it clear that this specimen
won't be mounted for display. Most of the museum's collections
are kept for scientific study, not exhibition.
After
removing some of the rock matrix, I found what looks like a vertebra
and possibly the pelvis. The work is moving pretty fast, but this
is a big jacket. We'll just see what shows up next.
Yvonne_Wilson
11-17-2001
11:59 AM
I
started a rhino hip/spine jacket today. I had to open the jacket
with a cast cutter like your doctor uses to cut the cast off your
broken arm. It isn't the prettiest fossil material I've ever seen.
The matrix has a big crack in the center --I don't know if that
was there initially or if it was broken on its trip from Kansas
to Pittsburgh. I soaked the bone that was showing with Butvar,
a glue, to help preserve it, and then started scraping off the
rock around the fossil. The matrix (rock) is really varied: some
of it is like loose sand, some like solid extra crunchy Rice Krispies,
and some is really, really hard. On the hard stuff I have to use
either a hammer and chisel or an air scribe, which is sort of
like a miniature jack hammer.
Allen
S. is working on a vertebra of the adult Camarasaurus today. It
is mostly prepared out of the rock so he is doing some more detailed
cleaning.
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