Re: Dryptosaurus, Deltadromeus, and Bahariasaurus

[se1aard@itis.com (Seth Ellestad)]

Thomas R. Holtz, Jr. wrote:
>Also, BEWARE OF THE DELTADROMEUS MOUNT! (Or it may come to life and get
>you...)  Well, more importantly, it is based on a LOT of conjecture, given
>that there is little known for this interesting beastie.  For example, I do
>not know of any evidence for the three-pronged ornament on the lacrimal
>(given that no skull material has been described for Deltadromeus), so that
>is entirely fantasy.
>
>Unfortunately, there is the push by museums and exhibitors to make mounts of
>creatures, even if there isn't the fossil material to back up said mounts.
>This would be less annoying if the mounts were color-coordinated to show
>what parts are based on real bones, and what on conjecture (as some
>museums do).

Based on what was found of Deltadromeus, I kind of figured that.  What was
the skull based on?  Best guess with some inference from Dryptosaurus
material?

>Sereno et al. (1996) report that most of the bones once refered to
>Bahariasaurus are actually from Deltadromeus.  The type (name-holder)
>specimen of Bahariasaurus, however, (2 dorsal vertebrae, a neural arch,
>three sacral vertebrae, rib fragments, pubes, and the proximal part of the
>ischium) are distinct from Deltadromeus and other North African theropods.
>The exact affinity of Bahariasaurus has not been worked out.
>
>The 4 ton estimate is primarily based on the femur mentioned above, now
>considered to come from a large Deltadromeus.

Aha.  That does clear things up a bit (from my end I mean).

>There do not seem to be any characters especially linking Deltadromeus or
>Dryptosaurus and either the Spinosauridae or the Coelophysidae.  The
>spinosaurid-coelophysid link is weaker than once thought, now that the
>anatomy of the former is better known (and is pretty clearly tetanurine).

How is the anatomy of Spinosauridae better known?  They didn't find more of
Spinosaurus did they?  I assume you mean with the recent study of Baryonyx?

>Hope this helps.

Yeah, it helps a lot, thanks!

Seth Ellestad.