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Re: Tyrannosaur paleopathologies, updates.



In a message dated 96-11-08 15:12:22 EST, dtanke@dns.magtech.ab.ca (D. Tanke)
writes:

> In 1910, Barnum Brown found a tyrannosaur bonebed near Drumheller,
> containing articulated skeletons! But........ there was so many
> specimens that he could high-grade, so he just collected one hind
> leg and about 6 left feet! A tyrannosaur pack mass mortality event??

Some of the specimens from this locality were publicly exhibited by the
American Museum of Natural History during the early 1920s. They're mentioned
by Matthew & Brown as definitively establishing that tyrannosaurids had
arctometatarsalian feet. Here's an excerpt from my review of tyrannosaurids
for Gakken about this bonebed:

<Brown's attention turned next to Alberta, Canada. At the end of the 1909
field season, Brown headed north from Montana to have a look around the Red
Deer River area. From Weston's and Lambe's writings, Brown knew that dinosaur
fossils were abundant there, but that particular trip seems to have been
prompted by a Canadian rancher who had visited the American Museum earlier
that year and spoken of fossils in the ground "just like" the ones on
display. Indeed, Brown was favorably impressed with his first-hand look, and
he resolved to return the following year.
        Brown planned to raft down the Red Deer River like his predecessors 
Weston
and Lambe, but he would do it with his famous panache. No small boats for
him; he supervised the construction of a barge atop whose deck was a complete
camp with a wall tent, a sheet-iron stove, and space to hold tons of jacketed
fossils. It was almost four meters across and about ten meters long--a
flatboat built specially for floating heavy cargo downriver. At the beginning
of summer in 1910, the vessel was launched at Red Deer, Alberta. After about
a hundred kilometers of swift water, the river settled down, and the fossil
hunters began to concentrate on the search for dinosaur-bearing localities.
Each year's field season ended with the barge farther downriver, piled high
with fossils destined for the American Museum in New York.
        In this manner in 1910 and 1911, Brown prospected what was then the 
lower
part of the Edmonton Formation but is now called the Horseshoe Canyon
Formation. Although he found mainly duckbilled dinosaurs and ceratopians--by
far the commonest dinosaurs of southern Alberta--he and his team also
excavated a bone bed of several Albertosaurus sarcophagus individuals jumbled
together, located three kilometers (two miles) below the Tolman Ferry on the
left bank of the river, 45 meters (150 feet) above the water level. (Inasmuch
as more than one species of tyrannosaurid now seems to be present in the
Horseshoe Canyon Formation, further examination may disclose that it was not
really an Albertosaurus sarcophagus bone bed.) For the first time,
dinosaurologists could examine complete hind feet of tyrannosaurids, and they
discovered how similar the feet were to those of Marsh's ornithomimids. The
better specimens were removed from the bone bed and collectively catalogued
as AMNH 5224. A skull, hind limb, and tail from this quarry were for some
time exhibited at the museum. Another, half-complete, largely disarticulated
skull (AMNH 5222; Figure 14) was found close by (but probably not in the bone
bed itself). Kenneth Carpenter reported in 1992 that this skull is now
rearticulated, revealing that it belonged to a short-and-broad-snouted
tyrannosaurid.
        In 1912, the barge left the Edmonton Formation behind and entered the
geologically older Belly River Formation. Spectacular dinosaur finds
continued to accumulate, and during the next three years, Brown and his team
excavated most of the classic Belly River tyrannosaurid specimens--as well as
vast quantities of other dinosaurs--that for many decades were on public
display at the American Museum and whose photographs grace many a popular
dinosaur book.>