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Show
prep is continuing on our duckbill! Time for a little
background information. Gil, AKA RMDRC 04-001, was
discovered in 2004 by "JC" Gil McIntyre. It comes from the
upper Judith River Formation, putting its age somewhere
around 75 million years old. Excavation began on June 26,
2004 and had been completed by July 2nd. Gil wad found in a
fairly soft sandstone with low overburden, which greatly
sped up the recovery.
Above
is a sketch of the site when TPI field crews excavated it
that summer. As you can see it is highly articulated but
missing the skull and lower legs. Unfortunately for
hadrosaurine hadrosaurs those also happen to be the most
distinctive parts, so identification down to genus is still
a little tentative. We have been considering Gil to beling
to Miasaura, however there exists the possibility
that It could belong to two other non-crested duckbills that
existed at the same time: Gryposaurus or
Prosaurolophus. Below is a photo of the 54cm long right
humerus, which may or may not be distinctive. In any case
it's pretty, and also slightly longer than the radius.
.JPG)
Prep
work is ongoing to find more distinctive skeletal elements,
so that we may get a better idea of the true identity of
this critter. Special thanks goes out to Dr. James Kirkland
for providing PDF reprints so that I may attempt to clear
this up!
We've
been able to do a slight bit of preparation on a
Maiasaura that was collected by
TPI crews in 2004 from the upper Judith River Fm of
Montana. Unfortunately no skin was discovered preserved in
this jacket, however there were a few surprises.
The
anterior 6 vertebrae show pathological neural spines,
perhaps an old bite wound that healed. The chevrons
(Y-shaped bones under the tail) are tiny, much smaller than
what would normally be expected on a
dukbill of this size.
This jacket contains 32 articulated caudal vertebrae in
a string nearly 8 feet long. Strangely the chevrons are
all nearly gone and the ossified ligaments normally
found in
ornithischian dinosaurs are completely missing.
Even
though the past two (hot) expeditions to Kansas have been
primarily aimed at recovering various
Xiphactinus skeletons that we have discovered
over the years, we did have a little time to scout some
outcrops low in the
Niobrara chalk. Last Monday, I stumbled across some
fish skull parts on an outcrop and followed them up to their
source. This is what was coming out:
The
rostrum of this rare fish is the most commonly discovered
part recovered, mostly because it is the densest and most
durable bit, and most likely to be found after weathering
out of the outcrop. The teeth are tiny and resemble small
barbs, though they number in the thousands. We may have
found
postcranial material with this fish as well, and a
recovery operation at the site will be attempted next time
we go to Kansas, though that may be a few months.
Martinichtys seems to have gone extinct
between Marker units 5 and 6 (this specimen is the
highest one I can find data for, about 1m below MU 6),
as do several other animals int he
Niobrara (such as
Thryptodus,
Tylosaurus
kansasensis, and several invertebrates). I am
curious what happened to wipe these species out.
Well,
field season started off with a bang this year. The little
mosasaur snout I found in late April turned out to be a
nearly complete specimen of Clidastes c.f. moorevillensis,
which isn't really supposed to be in the chalk. The critter
measures 4.8m long (16 feet), and is so well preserved that
it retains cartilage in the ear, sternum, sternal ribs and
above the scapulas.
Above, Mike Triebold uses a chainsaw with a special blade to
separate the block away from the outcrop prior to jacketing.
This chalk was the hardest we've ever encountered in nearly
3 decades of collecting in the Niobrara.
The
site as seen from the top of an adjacent bluff. Luckily
we could drive up to the site to drop off air
compressors and generators!
Below is the prepared front
half of the animal. 45cm (18 inches) of backbone was
lost in the mid dorsal section due to erosion years
ago. The tail section was taken out in another large
jacket. Come see the specimen, now on display in our
marine hall at the RMDRC!
A small project that I've
been involved in for a few years, the discovery of the first
heteromorph (open coiled) ammonite from the Niobrara Chalk.
Citation:
Everhart, M.J. and Maltese, A. 2010. First report of a
heteromorph ammonite, cf.
Glyptoxoceras,
from the Smoky Hill Chalk (Santonian) of western Kansas,
and a brief review of Niobrara cephalopods. Kansas
Academy of Science, Transactions 113:(1-2):64-70.
We discovered the specimen while excavating the "Tracie"
Tylosaurus nepaeolicus specimen in June 2008. Triebold Paleontology Inc. donated the ammonite
to the Sternberg Museum at Fort Hays State University in
2009 after it became clear this was a scientifically
important critter.
Email me if you need a PDF copy of the paper.
Well we're heading
out again for a quickie recon before my trip to Korea. Hopefully it will be
more productive then the last trip, which was a lot of uphill and downhill
walking and very little in return. We recovered a partial Xiphactinus
skull that I found accidentally last spring, and I found another skull and
partial skeleton (so far, it's still going into the outcrop) that we'll be
puling out later this spring. Above the first Xiphactinus, I also
found and recovered a small turtle, probably Ctenochelys, that even
had limb material. This next trip will not have a film crew, so things
should go pretty quick!
As many
of you know, we had to remove our big Daspletosaurus, Pete
3, in 75 different jackets. Jacket RMDRC 06-005-72 was done
with a pallet method, weighing in at 4 tons.
Paper here on the process.
This week we are making a concerted effort to take that
enormous jacket apart, in hopes of keeping it stable as
well as recovering a large section of real estate smack
dab in the center of the lab. Unfortunately, some bones
are going to have to be broken or cut to "unjackstraw"
them, but will be reassembled later. The jackstrawed
nature of the bones (as well as their fragility) is what
made us remove the huge block in the first place, so
it's not like it's a huge surprise. Still, it is a lot
of work.
BCT,
our large Daspletosaurus that was excavated from 2001 to
2003 from a very very very hard sandstone in eastern Montana
is now finished with prep. Paleo teach Jacob Jett finished
the last dorsal vertebra, that was encased in a big ugly
block of ironstone concretion. I'm just happy I didn't have
to work on that!
Just to toot our own horn.
There is a new name
for the giant fish formerly known as Protosphyraena gladius. This
fish has been known since the 1870s int he Niobrara Chalk, and Cope
himself in 1875 had described the pectoral fins of (then) "Portheus"
gladius as a "formidable weapon, and could readily be used to
split wood in the fossilized condition". We here at the RMDRC do not
condone the use of fossil fish fins for wood splitting.
The article covers
two specimens, one that we prepared here in 2008, the other that we
assisted Mike Everhart in collecting and are still working on.
The work showed
that this fish, though related to the cretaceous swordfish analogue
Protosphyraena perniciosa, was in fact a planktivorous filter
feeder, much like modern whale sharks and manta rays. This type of
feeding behavior was not yet reported for animals in the western
interior seaway, and is pretty exciting, especially for an animal with a
complete lack of sharp pointy teeth.
We are currently
working on the first 3d reconstruction made from casts of the specimens
in our collection. Keep checking back for progress! Painting at top
Copyright Robert Nicholls, used in our paper.
Daspletosaurus vs. T-rex
One of Pete 3's humerus compared to a cast of Peck's Rex. The other
humerus is awaiting removal from the main jacket.
Pete 3 is
rolling along in prep, with 5 jackets finished in the past week (to
be fair, 2 of them were 95% done when we shelved the project last
May). I'm working through the dorsal ribs and gastralia (belly
ribs), because they're quick and easy and usually the last thing
anyone wants to work on. The rib head below was finished yesterday,
part of the material we had to pull off of the 4-ton jacket early in
the prep process. The remainder of the shaft is still on the
to-be-prepared shelves, but I hope to get to it very soon. Man, this
Daspletosaurus was big.
For all of you
out there keeping tabs on our
Daspletosaurus prep projects (which seem to be hitting
high gear again), you probably know how much I complain about the
matrix and bone quality issues on them. For
BCT,
it's soft-ish
bone locked in a hard sandstone with Ironstone concretion. On the
exact opposite end of the spectrum it is Pete 3 with very soft sandy
matrix encasing super fragile and shattered bones.
Congrats
Matt on making the volume available, and I hope to see some blog
readers at this years meeting in Chicago.
If you've been
following the
RMDRC newsletter since our museum opened, you're probably
familiar with our
BCT
Daspletosaurus
n. sp.
specimen, nicknamed "Sir William". If so, skip ahead a bit.
BCT
is a tyrannosaur discovered in 2001 in central Montana. It was
originally thought to be in the Hell Creek Formation, making it a
small Tyrannosaurus
rex.
Later, in 2005, it was discovered that the rocks were actually lower
Judith River Formation, meaning that it is most likely
Daspletosaurus. This specimen is an adult at 16 years of
age (as determined by Greg Erickson) but displays some
non-traditional
Daspletosaurus traits, such as only 13
dentary
alveoli
(lower jaw tooth sockets), incidentally the same number as normally
found in T.
rex.
Curious.
The excavation
was very difficult, and took the summers of 2002 and 2003. The bones
were encased in a combination of hard sandstone and ironstone
concretions. Preparation was likewise slow.
This cervical
vertebra is one of the last bones to be prepared from
BCT,
starting out as a 40 pound block of hard hard rock. After 30 hours
of air scribe and air abrasion work this giant and beautiful bone is
nearly done. Good job, Jacob, in getting this specimen ready for
display!
OK, embedding
of this Xiphactinus is done, assembly is done, now all that
is ahead of us are hours upon hours of detailing. That and figuring
out exactly how it's getting upright. That will be an interesting
day... I don't think I want to take video of that.
On the
bright side not only is the project almost done, but to preserve
our sanity Jacob and I have been able to devote one hour at the
end of each day to preparing other stuff. Special treat for
follower Saurian, Jacob has been preparing a cervical vertebra
from our
BCT
specimen of
Daspletosaurus n.
sp.,
out of the lower Judith River Fm. I on the other hand have a
special secret non-dinosaur project, that I hope I'll be able to
reveal in the first quarter of the new year. It's very exciting,
trust me!
Below is a
new photo of the progress made in the past week. Exciting, no?
Well, assembly
is pretty much finished! Leroy is embedded and now all that lies
ahead are weeks and weeks of detail work. And of course the whole
how the heck are we going to get that slab upright. It's
ok,
I have a plan, sort of. If it doesn't work you will all know about
it in a few weeks. The mount right now weighs in at about 1200
pounds. Jacob is pointing to the specimen for scale. It's hard to
get it all in one shot, with the overall size of 16'x7'. We need to
start finding smaller fish.
As some of you
may know, we are currently working on the construction of a plaque
mounted Xiphactinus, nicknamed "Leroy", that was collected in the
mid 1990s. "Leroy" is a big Xiphactinus at 15 feet, however not
quite as large as "Mildred", the 18 foot long monster that we
collected in the summer of 2008.
Making a
plaque mount is a very time and labor intensive process,
espescially when the bones are jumbled when in the ground. Each
individual element must be removed and prepared, and of course
prepared on the correct side. The right side of the skull was
the best and prepared side, which drove our decision to have the
right side of the entire fish displayed.
I'll post photos of or
progress as we move forward. This is what the project looked like nearly a
month ago when the major preparation was finished, and we decided to start
laying out the fossil bones. Curator doing the classic TPI field pose
(pointing "There it is") for scale. The size of the project is deceiving,
the black rectangle is a 16 by 5 foot area of steel and 3/4" plywood. The
chicken wire mesh is for strength of the material used to embed the bones.
You can probably see that there are literally hundreds of individual bones
(spines, fins and ribs)missing. The simple reason is that in this early
stage, we don't want too much stuff floating around. You will see these
elements get put in later stages of the process.
I've been
slacking, I admit it. Here's the challenge of the week: The photo
below is definitely a squamosal off of a chasmosaurine ceratopsian.
The question is which one? Pleas guess int he comments section.
Our new specimen of
Pentanogmius evolutus, RMDRC 09-015,
is now on display in the marine hall. This specimen was collected
from the lower Niobrara chalk in Lane Co, Kansas earlier this year.
Missing only the tail, this is one of the most complete and one of
the few articulated specimens ever found of this uncommon fish. It's
deep body and giant sail make it over 3 feet tall, with a total
length of 5-6 feet. Pentanogmius was shown in the National
Geographic IMAX film Sea Monsters, along with our
Dolichorhynchops and Xiphactinus specimens also on
display in the marine hall. As always, our exhibits are constantly
changing, so come by this holiday season and see what else we're
working on.
Painting of
Pentanogmius evolutus
adapted from an original work (Plate 30) by Deb Bennett (1983) as
published in Kansas Geology, Rex Buchanan (ed.), University of Kansas
Press, 1983. Image from
http://www.oceansofkansas.com
Another rare fish
The
Niobrara
sea was home to more than just
Xiphactinus
and sharks. There are dozens of other species of fish, some known very
well, others from scrappy remains.
One of
the rarest is the fish formerly known as
Bananogmius,
now
Pentanogmius. The name change is sad, really, because I
quite enjoy saying "Bananogmius",
although not quite as much as I love getting other people to try
saying it. It was a large fish with no big teeth, yet a large sail
fin running the length of the animal. It had only tiny pectoral and
pelvic fins.
The RMDRC
has a new articulated specimen (photo above) recovered this year off
of private land. The skull is to the left, with the sail fin taking
most of the upper half of the large jacket. This one is much larger
(over 5 feet long), more complete, and better preserved than the new
Denver specimen. It has been "show prepped" to a plaque stage, and
will be molded as is. This will get the fish ready for 3d
reconstruction using casts of the original bones.
Preparing Fish
Nice specimens of Xiphactinus audax can be found occasionally in
the Niobrara chalk, however articulated fish are extraordinarily rare.
Unfortunately a jumbled pile of bones is not very pretty, so this month
we are attempting to reconstruct a 15 foot fish as a panel (flat)
mounted skeleton.
Above is the skull of the fish, nicknamed "Leroy". It is currently
partially prepared and has been on display in our marine hall since the
museum opened over 5 years ago. The body was collected sometime in the
mid 1990s. Below you can see Jacob Jett preparing one of the many
jacketed slabs of bone and chalk. Trust me, that's really his hand.
I'll
continue to update as we proceed, however progress is slow due to how
delicate fish bones are, even on these giant predators. Stop by and
watch us work in the lab, we will be at this for a while!
New Turtle Display Almost Done!
I just
wanted everyone to know our new surrogate marine hall is about finished
and ready to open, hopefully for this (cold) weekend. We've got quite a
turtle-heavy display, featuring skeletons of
Archelon,
Protostega,
Toxochelys,
Prionochelys
and the shell of
Bothremys.
Also on display is a
mosasaur-bitten
Toxochelys
shell, RMDRC
08-003 "Kraigums"
that I discovered last spring, as well as the only real bones of
Megalocoelacanthus
dobiei
on public display anywhere, the youngest fossil
coelacanth
found. There are also many more marine touch stations too. Please stop
by and let us know what you think!
Holly is done!
The
Pteranodon sternbergi
specimen (RMDRC 09-007) I discovered this spring was about 70% complete.
The restored elements (mostly parts of the left wing and the lower jaw)
are casts of
CMNFV 41358, AKA "The Triebold Specimen". It is embedded in an
artificial matrix simply because squashed flat bones are not useful for
3d specimen mounts. I am so happy this project is finally finished.
Disassembling Joyce
Our
Lambeosaurus,
Joyce (RMDRC
07-020) is being prepared, partly because the dang main jacket (map
above) is taking up way too much space in the prep area of the lab. The
problem is that the bones are very difficult to
separate.
They are
jackstrawed together, brittle, and now that all of the water has
evaporated out of the jacket, the matrix is much harder.
The
site with
Kraig and Jacob while exposed for NBC camera crew.
Below
is the main block before
jacketing.
Getting this apart is our newest challenge.
A jacket of
WXT, a
huge
Edmontosaurus specimen discovered in southern North Dakota
2002, was brought into the lab for preparation this past week. Before I
could even begin, I noticed the scale pattern of the skin preserved as a
film on one bone. Skin is uncommon but not unheard of in the Hell Creek
Formation.
Further poking
around showed scales preserved in the sandstone matrix in 3 dimensions.
The scales themselves are only a few
millimeters
thick, and are preserved in a layer that will not separate easily. I'm
now determining the extent of the skin present, and what should be done
to it to best preserve it. The
photo
below shows one of the
counterparts of the skin impression that was removed from the
block.
So, you wanna
dig dinosaurs?
We're
looking for a few volunteers to come with us to central Montana
this summer to help scout, recover the rest of our giant
Basilemys turtle and begin excavation on a big hardosaur (the
tibia is over 4 feet long). Our crew will be leaving from
Colorado on July 28th, and will likely stay for 2 weeks. We will
be headquartered out of a camping lodge, and there is no cost to
volunteers besides transportation and food. All excavation
equipment and supplies will be provided, personal tools are to
be brought by each person attending. More on that after
applications are reviewed.
Applications may be sent to me at anthony@rmdrc.com and should
outline biology or geology experience. This trip is a wonderful
way to gain experience for undergrad and graduate students in
field collection methods. We will be focusing not only on
excavation techniques, but data collection (mapping,
stratigraphic sections and correlation, taphonomy) as well as
site evaluation.
 We
have a new addition to the
RMDRC
mosasaur family: a
Platecarpus
ictericus from the upper
Niobrara Chalk of Logan County, KS. I discovered this one
on June 17th,
but we didn't return to excavate till the 19th.
It
appears to be a complete skull and cervical series, with a
number of articulated dorsal vertebrae and ribs. The skull
is scattered, but preserves not only all of the bones, but
also calcified cartilage. This specimen is a great candidate
for further preparation and 3d
mounting. Judging by the size of the lower jaws (18 inches)
the complete animal would probably be 18 feet long.
Unfortunately, scavenging sharks (probably
Squalicorax
kaupi, however a
Cretoxyrhina
mantelli tooth was also found on the same
outcrop, rare in the upper chalk) forcibly removed the front
limbs from
Bev
before she hit the bottom of the Western Interior Seaway 83
million years ago.
 You
may notice that we give nicknames to the specimens, and
there is a great reason why. This
mosasaur was discovered about 30 feet away from
(and 15 minutes after) another
Platecarpus specimen on the same outcrop.
Instead of referring to them a "you know, the first
mosasaur that Jacob found that week", we name
them to keep them straight, both in the field and the
lab.
The
person that discovers the specimen gets the naming
rights. In this case
Bev is named after my mother. It's a great way of
discovering which relatives like you best.
Tuesday, June
23, 2009
Fun in the Chalk
It was a good trip...
We only got 2 days
of scouting in before getting rained out of the field on Saturday,
however we found some good new specimens.
Jacob Jett was able to find
his first mosasaur,
a Platecarpus specimen in the upper chalk of Logan County.
I stumbled upon
another mosasaur,
Platecarpus ictericus, about 30 feet further down the same
gully, and elsewhere on the same private ranch I discovered the hips of
a large diving
bird, Hesperornis.
 Thursday
we spent the day excavating a giant fish
with Mike Everhart, currently identified
as Protosphyraena
gladius, however that seems likely to change in the next few years.
It was extremely hot and humid, with the temperature at 7:00pm at 103
degrees. The photograph
shows Mike Everhart,
Jacob Jett and a little
bit of Mike
Triebold at the excavation site.
Friday and Saturday
were spent excavating
the Platecarpus specimens, and all the fossils made it
safely back to our lab. Be sure to stop by in the next month to watch us
prepare these critters and more in our lab viewing area.
Off to the field!
No fossil of the
week this time, our field crew will be headed off to the
Niobrara
Chalk in western Kansas bright and early Wednesday morning to
investigate and recover more sea critters. I'll be taking lots of
photographs so you can all see who's there and what we do, even some of
the stuff we don't tell you about on our tours of the
RMDRC.
Currently in
the ground we have a small shark (probably
Squalicorax
falcatus),
a small (12 foot)
Xiphactinus
audax,
and a gigantic (18 foot plus)
Xiphactinus
that was partially poached from the rancher's property. Also, we'll
be
investigating a giant clam,
Platyceramus, in hopes of putting it on display in our
marine hall this summer. And who knows just what we may stumble upon
once we start scouting!
Fossil of the week:
6/9/09
Let's
talk big fish this week!
Ichthyodectid
fish are amongst the most common fish found in the
Niobrara
chalk. The genera
Prosaurodon,
Saurodon,
Saurocephalus,
Gillicus,
Ichthyodectes and the giant
Xiphactinus
are all found at various stratigraphic levels. Fish have very delicate
skulls, however many times they are recovered articulated. It is
impossible to disassemble these skulls without damaging them, so we
usually prepare them in profile view. Sometimes they are
disarticluated,
looking like they reenacted the final scene from "Jaws 3D". These
scattered skulls enable us to reassemble the
pieces
and take out some of the crushing distortion from 82-86 million years of
burial.
The photo is of a
specimen of
Saurodon
leanus
named "Tony" that I discovered in Logan County, Kansas in October of
2006.
Stratigraphically we're at about marker unit 18, so fairly high
in the chalk, nearing the Pierre Shale contact. This is one of the more
rare fish in the chalk, caricterized by it's long eel-like body and
distinctive chin spike. As you can see, the bones of the skull have
blown all apart, making this specimen a great candidate for molding and
3d reconstruction. No one is quite sure what the spike is used for, my
guess is probing into the bottom
mud of
the western interior seaway looking for soft bodied invertebrates (such
as worms) to eat. Hopefully we'll find more specimens in the future that
may include stomach contents.
Fossil of the week:
5/29/09
 This
past week I was attending the 8th
Conference on Fossil Resources in St. George, UT. The second group of talks
all focused on the
Campanian aged flora and fauna of the western interior. A few brief
mentions of the poor neglected duckbill dinosaur fauna were made, but I
wanted to share with you an image of one that I'd love to find: "The
duckbill that ate
Manhattan!" Paleo
Tech Jacob Jett
(6'4" tall, shown back in his younger days) is shown for scale.
This
isolated rib bone was discovered in the upper Judith River Formation (Campanian
aged) in the summer of 2004 while excavating a
centrosaurine
horned dinosaur called "UTC".
Isolated duckbill skeletal remains are not uncommon at dig sites. In
fact, juvenile
hadrosaur jaws have been found at both our "Joyce" and "Pete 3"
sites in the same area.
Unfortunately, isolated
postcranial
remains on
hadrosaurs aren't very diagnostic, so it is impossible to say
which critter this rib belongs to. It is a good deal longer than our
longest rib on "Big Ed", the 34 foot long
Edmontosaurus
annectens
that is now on display in Korea. I'd estimate the body length of this
duckbill to be at least 40 feet.
About
Our Lab
The Rocky Mountain Dinosaur Resource Center is home to one of the largest
fossil preparation labs in the world. Here, paleontologists and Paleo
Technicians painstakingly remove rock and glue from fossils in order to ready
them for display. In some cases, the most important of these fossils are later
molded so their casts may be displayed in museums around the world. Working on
specimens new to science is a common occurrence.
Past
Projects
Some of
our previous projects may be seen on display at the RMDRC as well as museums
worldwide. Here's a list of some of our previous efforts:
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