What ever happened to Deinodon?

[Saurischia@aol.com]

I'm not a professional - I'm just grown up childhood dinosaur enthusiast 
with a failing memory.  I was wondering if someone could summarize for me 
what criteria caused reclassification of Tyrannosaurus and his kin over 
the years.  Why were the Theropod infraorders Coelurosauria and 
Carnosauria dropped - was the line drawn between them too ambiguous?  
I've noticed the Ornithosuchidae were extracted from Carnosauria and 
given a suborder to replace the Pseudosuchian Thecodonts.  Is this 
Ornithosuchia suborder now believed the common ancestor between 
Saurischia and Ornithoschia?  And I remember Tyrannosauridae was once 
also referred to as Deinodontidae, and Gorgosaurus as Deinodon.  (Am I 
right in assuming Gorgosaurus and Deinodon are now both synonymous with 
Albertosaurus?  At one point Albertosaurus and Gorgosaurus were 
considered different animals.)  As I'm not current in paleontology, I 
find myself getting confused, especially since my library is outdated.

Why do new genus names sometimes replace older ones?  I always liked the 
name Brontosaurus better than Apatosaurus.  (I remember there was an 
issue over a missing Brontosaurus skull - was that a factor?)  I always 
liked the name Trachodon too, perhaps only due to childhood familiarity.  
That's a name I NEVER see anymore.  I thought Trachodon was renamed 
Anatosaurus but I have one *old* book that lists them as two separate 
specimens, and a newer book that doesn't list Trachodon at all.  And at 
some point in the past I thought Antrodemus was going to replace 
Allosaurus, but I'm glad to see that it hasn't.

--Christopher Sirmons Haviland