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Re: A few questions



Dino Rampage wrote-

> 2) There has been speculation that Lurdusaurus has a body form that is
> convergent with the ground sloths. Any good reconstructions to illustrate
> this?

No.

> 3) What is the current taxonomic status of the giant caenagnathid? Is it
> Chirostenotes pergracilis, a new species of Chirostenotes or a new genus?

It has not been described yet, but word is it's a new species of
Chirostenotes.  Certainly looks similar enough to me.

> 4) How does Chirostenotes pergracilis appear different from C. sternbergi?

The later has a higher ridge on the jaw articulation, shorter and wider
medial glenoid and a narrower ramus in front of the jaw articulation.
Specimens questionably referred to have additional differences in the
dentary.  If Elmisaurus elegans is synonymous, several postcranial
differences are also known.

> 5) What formation is Gryposaurus latidens from? I've tried searching, but
> all I can find is that it was from the Early Campanian of Montana

Two Medicine Formation

> 6) Are there any good restorations of the many species of Monoclonius? And
> what is Monoclonius exactly? A valid centrosaurine genus related to
> Centrosaurus, a genus closer to Einiosaurus, or is it merely a mixture of
> assorted ceratopsid bones?

Only M. crassus (= M. lowei) is potentially valid.  Most people think it's a
subadult centrosaurine, though a few believe it is a valid neotonic taxon
(probably basal to Centrosaurus + Styracosaurus and Achelousaurus +
Einiosaurus + Pachyrhinosaurus).  M. dawsoni and cutleri are synonyms of
Centrosaurus, M. sphenocerus and M. nasicornis are synonyms of
Styracosaurus, M. belli and M. canadensis are synonyms of Chasmosaurus, M.
fissus and M. recurvicornis are indeterminate

> 7) Is there any news on the carcharodontosaurine that is supposedly larger
> than Giganotosaurus?

Nothing new.  It will be described very soon though.

> 9) I understand that Ornatotholus browni is now a species of Stegoceras,
and
> that S. brevis and S. edmontonensis are now species of Prenocephale. Why
the
> sudden change? And how are these related to Tylocephale and Gravitholus?
All
> these small pachycephalosaurids look quite similar to me.

Stegoceras Lambe 1902
= Ornatotholus Galton and Sues 1983
S. validum Lambe 1902
= Troodon validus Gilmore 1924
= Stegoceras browni Wall and Galton 1979
= Ornatotholus browni Galton and Sues 1983
late Campanian, LC
Judith River Formation, Alberta, Canada
Comments- Ornatotholus has a parietal identical to Stegoceras and is
synonymous (Sullivan, 2000).
References- Sullivan, 2000. Stegoceras revisited. JVP 20(3) 72A

"Stegoceras" lambei Sternberg 1945
Comments- This taxon is a new genus (Sullivan, 2000).
References- Sullivan, 2000. Stegoceras revisited. JVP 20(3) 72A

Gravitholus Wall and Galton 1979
G. sternbergi (Brown and Schlaikjer 1943) Sullivan 2000
= Troodon sternbergi Brown and Schlaikjer 1943
= Stegoceras sternbergi
= Gravitholus albertae Wall and Galton 1979
late Campanian, LC
Oldman Formation, Alberta, Canada
Comments- Stegoceras sternbergi is the same as Gravitholus albertae, making
the new combination Gravitholus sternbergi (Sullivan, 2000).
References- Sullivan, 2000. Stegoceras revisited. JVP 20(3) 72A

Tylocephale Maryanska and Osmolska 1974
T. gilmorei Maryanska and Osmolska 1974
middle Campanian, LC
Barun Goyot Formation, Mongolia

Prenocephale Maryanska and Osmolska 1974
P. prenes Maryanska and Osmolska 1974
late Campanian-early Maastrichtian, LC
Nemegt Formation, Mongolia
material- (ZPAL MgD-I/104)
(ZPAL MgD-I/105)
P. brevis (Lambe 1918) Sullivan 2000
= Stegoceras breve Lambe 1918
= Troodon brevis Hay 1930
late Campanian, LC
Judith River Formation, Alberta, Canada
syntype- (NMC 1423) (juvenile) frontoparietal dome
plesiotypes- (NMC 121) frontoparietal dome
(NMC 193) (juvenile) frontoparietal dome
(NMC 194) (juvenile) frontoparietal dome
(NMC 8819) (juvenile) frontoparietal dome
P. edmontonensis (Brown and Schlaikjer 1940) Sullivan 2000
= Troodon edmontonensis Brown and Schlaikjer 1940
early Maastrichtian-late Maastrchtian, LC
Horseshoe Canyon Formation, Alberta, Canada; Hell Creek Formation, Montana,
US

Mickey Mortimer