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Royal Tyrrell Museum Update #10: Fieldwork



 1. My field season is finally over- almost 4.5 months away from home. This
update will describe the subadult ceratopsian skeleton we just collected
near Manyberries, Alberta (very S.E. corner of the province). I had
originally collected a partial skull at the locality in 1990. Subsequent
erosion exposed a whole hind foot. 3 of us removed all the siltstone
overburden (8 metres long, 3 metres wide and up to 2.5 metres high) in a
stunning 2.5 hours, and only by pick and shovel! The skeleton is both
articulated and disarticulated, but the following was documented: most of
the vertebral column is present. The cervicals (neck) and dorsals (back)
vertebrae are disarticulated, but it seems we might only be missing about 2
cervicals. The sacrum was not seen, but is believed to be present with the
pelvis. A perfect articulated tail- complete to the very tip was found. This
animal had an "OWEEE" on its tail- 3 mid-caudals are fused and swollen. As
for ribs, we saw many disarticulated dorsal ribs from both sides, but no
cervical ribs. Except for sternal plates, both shoulder girdles are present.
There is little of the forearms- both humeri (upper arm bones) and nothing
more. We found both ilia lying parallel with what appeared to be an ischium
in articulation so we believe the sacrum and pelvis are complete and
articulated to the tail. The left hind leg is represented by the femur only.
The right hind leg is complete. We found a few more pieces of the skull- a
complete right maxilla with teeth and a surangular/articular complex (hinge
joint on lower jaws). We did not find the snout region (unfortunately) nor
any of the rest of the lower jaws. A few other bones were found but only a
little of them could be uncovered due to other bones sitting on top of them.
So, all in all, not a bad find. The sedimentology of the site told an
interesting story. The ceratopsian carcass was moved to the present locality
in a flood event which deposited much plant fragments, tree trunks, etc. The
body was laying on its right side. The right hind leg, pelvis and tail were
buried almost immediately, but not before the tail could be swung around and
point its tip downstream, and, like a wind vane, acted as a paleocurrent
indicator. A little later, another more vigorous flood event diarticulated
the exposed and rotting carcass. This second flood event deposited a
wonderful microsite of small vertebrate fossils. As we uncovered the
skeleton we found Garfish LEPISOSTEUS scales and vertebrae, Bowfin AMIA
vertebrae, rayfish MYLEDAPHUS teeth in the thousands. There was also a bird
femur end, CHAMPSOSAURUS lower jaw, amber, charcoal, lizard jaw cf. CHAMOPS,
2 toothless mammal jaws, dozens of tyrannosaur and small theropod teeth,
salamander vertebrae, dozens of small coprolites (probably turtle or croc)
and many other bone fragments. In the absence of a snout, identification of
the ceratopsian proves difficult. It is NOT Centrosaurus which is by far the
most dominant ceratopsian found in south Alberta. The frill with its short
spikes seems to ally it with one of Scott Sampsons 2 new Montana
ceratopsians- if so, this animal will be important as it is an associated
skeleton and Scott's material is disarticulated bonebed material. We had 2
days of snow with temperatures at night of -7 degrees C- they never tell you
about that in all those dinosaur books. Nor the several days with highs of
+5 degrees C in a 35 km/h wind- you figure out the windchill factor.
Fortunately the cold killed off the mosquitoes- the few I saw were the
biggest i'd ever seen. The locals knew this as a fact and a nearby store
sold small, working leghold mosquito traps!

 2. As many of you probably already know, the Konglong exhibit of Canadian
and Chinese dinosaurs will be taken down, starting Oct. 15th. It is supposed
to be going to Australia- I'll provide times and places when I know.

 3. When we were down south, there were rumors of yet another tyrannosaur
skeleton just being found in the Drumheller area. More on this later....


      
 Darren Tanke, Technician I, Dinosaur Research Program, Royal Tyrrell Museum
of Palaeontology, Drumheller, Alberta, Canada. 
 Interested in all aspects of centrosaurine ceratopsians, paleopathology,
recent and fossil dento- and osteopathy; senior editor on annotated
bibliography of extinct/extant vertebrate dental pathology, osteopathy and
related topics (9,911 entries as of Sept. 14, 1996). 

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