Re: My Phylogeny: Growing Science...

["David Marjanovic" <david.marjanovic@gmx.at>]

----- Original Message -----
From: "Jaime A. Headden" <qilongia@yahoo.com>
To: <dinosaur@usc.edu>
Cc: <Mickey_Mortimer11@msn.com>; <david.marjanovic@gmx.at>
        [no problem, but we all get it twice that way]
Sent: Friday, September 28, 2001 11:36 PM

>   Caenagnathids most certainly do not have interdental plates. And
frankly, neither do
> troodontids. I have no idea where the latter came from, but I feel that I
am partially responsible
> in that I suggest to Mickey somewhere that the medial alveolar wall of the
dentary in
> *Caenagnathasia* was analogous to the condition of interdental plates, as
in Troodontids. Well,
> neither have interdental plates (see Currie, 1987, in _JVP_, and Currie et
al. 1994 {cited 1993),
> in _Canadian Journal of Earth Sciences_).

I brought the statement that troodontids have some onlist, quoting the
description of *Eoraptor*, as follows. Of course I haven't seen any relevant
fossil or most of the primary literature and can't say anything on my own.

"Only a small part of the left maxilla is preserved [...] The interdental
plates are small pointed processes, recalling the interdental plates on the
dentary of *Troodon* (Currie, 1987), which are not clearly differentiated
from the lingual surface of the maxilla."
"As in the maxilla, the interdentary [sic] plates are small spikes that
project between the alveoli and cannot be reliably differentiated from the
bone on the dentary's labial surface. The lingual alveolar margin thus
resembles that of *Deinonychus* (Ostrom, 1969). In *Eotyrannus* the plates
may, therefore, be fully fused or, as is the case with *Deinonychus*,
reference to these structures as interdental plates may be a question of
semantics (Currie, 1987, 1995; Ostrom, 1990)."

Stephen Hutt, Darren Naish, David M. Martill, Michael J. Barker and Penny
Newbery: A preliminary account of a new tyrannosauroid theropod from the
Wessex Formation (Early Cretaceous) of southern England, Cretaceous Research
22, 227 -- 242 (2001)

I wish all preliminary accounts were so large...

> <Yes, but it's crushed and broken.  I don't think any useful information
can be seen, but Jaime's
> drawn a reconstruction.  I'm skeptical of his drawing to say the least...>

Are you sure that long ?broken rod fused to the back of the skull is the
quadratojugal, as in your drawings, rather than the jugal, as might be
guessed from its length?

> <<18 -- Do we know *Avimimus* has no interdental plates?>>
>
> <Only the premaxillae and dentary tip have been found with "dentigerous"
margins. The lack of
> teeth is associated with the lack of unfused interdental plates as far as
I know. But it has been
> recently suggested Avimimus had premaxillary teeth, which could complicate
the issue.>
>
>   Again, the word as translated from Russian, _zubov_, refers to teeth as
well as anything
> toothlike,

(just for the record, I can't tell from my not very big dictionary; zub_ov_
is the genetive plural, anyway)

> and Barsbold has used the same word in connection with oviraptorids. Until
someone
> shows you an actual tooth in these, the actual premaxilla/maxilla (another
point Mickey and I
> disagree on), which is denticulated (_zubovishchnikaya_), bears about 6--7
denticulated points and
> the crenels between them are trinagular and are not likely to be eroded
bone (they are also
> regularly shaped), and this is apparent what Kurzanov meant when he wrote
in 1985 that the
> premaxilla bore about 4 teeth

Sounds plausible IMHO.

> (the Russian word, which I have available, used was _zubovoy_).

This is an adjective. Although it is definitely derived from tooth, my
dictionary only knows zubnoy... Do any of the following occur in the text,
which I _personally_ would expect for denticles:
    zubets: tooth, notch..., s zubtsami: serrated, zubok: (diminutive)