Re: New ankylosaur paper- Bissektipelta gen. nov.

["Mickey Mortimer" <Mickey_Mortimer111@msn.com>]

Ken Carpenter wrote-


> I reviewed the manuscript by Parish and Barrett on Amtosaurus. Their
Abstract states: "We conclude that > Amtosaurus magnus is a nimen dubium
that should be regarded as Dinosauria indeterminant." Now, this
> may have changed as I have not yet seen a copy of the published version.

Yes, they conclude basically the same thing in the final draft- "We conclude
that "Amtosaurus magnus" is a nomen dubium that should be regarded as
Ornithischia indeterminate."  My issue was with the authors' view of what a
nomen dubium was.  They use the term to mean a taxon without any unique
autapomorphies, as opposed to any taxon that can't be distinguished from
other taxa.  Amtosaurus may not have an autapomorphy in its braincase that
no other taxon does, but it seems to have a unique combination of characters
that make it distinct from other taxa.
BTW, Hill et al. (2003) indicate Nodocephalosaurus, Gargoyleosaurus and
Animantarx also have the sub-crescentric occipital condyle, that
distinguishes them from Amtosaurus.  Now someone just needs to compare the
latter to Gastonia, Minmi, Polacanthus(?), Shanxia and Struthiosaurus.

Mickey Mortimer