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Re: sinraptor/maniraptor



> 
> Finally, last week I asked about name changes (and received several 
> examples)--here's another one Gorgosaurus is now Albertasaurus? 
> 
> 
> 
Here's an abridged version of the taxonomic history of the genus 
Albertosaurus. It so happens that the first dinosaur skull found in Canada
was that of an Albertosaurus. But it wasn't the first dinosaur fossil found
in the country, as fragmentary bones had been discovered years before,
first in Saskatchewan (1874) and later in southern Alberta.
This fragmentary skull was found by J. B. Tyrrell in 1884 in the badlands
of the Red Deer river, near the modern-day city of Drumheller (central
Alberta). It found its way to the Geological Survey of Canada in Ottawa
(it resides today in the Paleobiology Laboratories of the Canadian Museum
of Nature, in the same city). It was studied by E. D. Cope who identified
it as Laelaps incrassatus, an invalid generic name since Marsh had renamed
this Dryptosaurus in 1877. 
At that time in Canada, there were no dinosaur specialists, so it wasn't
until 1905 that the generic name Albertosaurus was created based on that
skull and other fossils that had been found in the meantime. Albertosaurus
sarcophagus (the type-species) was described by the American paleontologist
H. F. Osborn; in that same article he also described Tyrannosaurus.
Another fossil (this time a skeleton) of a large theropod was found in 1913
by C. M. Sternberg in the vicinity of what is now Dinosaur Provincial Park.
The specimen was described as Gorgosaurus libratus by L. Lambe in 1914.
A second species (G. sternbergi) was erected in 1923 by Matthew and Brown
based on a skeleton found in 1917 by the Sternbergs.
Finally, Albertosaurus arctunguis was erected by W. A. Parks in 1928 based
on a fragmentary post-cranial skeleton found in 1923.

In 1970, in an article entitled _Tyrannosaurs from the Late Cretaceous of
Western Canada_, Dale Russell (an American-born paleontologist working in
Canada) provided a revision of the family Tyrannosauridae. It was in this
paper that he synonymized Gorgosaurus with Albertosaurus, transferring the
two species of Gorgosaurus to Albertosaurus. He also recognized that 
Albertosaurus sternbergi and A. arctunguis were junior synonyms of
A. libratus and A. sarcophagus, respectively. The latter have since been
considered the only two valid species of Albertosaurus.

As for the current phylogenetic and taxonomic status of Albertosaurus,
I shall make no comments (I haven't examined the problem and am not a
professional).
Please write if any of you have any questions regarding the historical
part of this post. I'll try my best to answer.

Michel Chartier
Universite de Montreal
chartiem@ere.umontreal.ca