Deltadromeus Vs Bahariasaurus

[Down under fossil hunter]

I am just wondering if you guys can help me, I have been collecting dinosaur teeth for several years now and have always been fascinated by them.

I am aware of Deltadromeus and Bahariasaurus and am equally aware that no skull material has been recovered from either species which is where my question comes from...... Are they the same thing? If you have a 3 inch theropod tooth from the Kem Kem that is neither Spinosaurus or Carcharodontosaurus then what is it?

Why do more and more reputable dealers list teeth belonging to both species?

I have obtained some of the better quality examples and to me they look like an inflated Carcharodontosaurus tooth.

I would be interested in all opinions.

Cheers

[jacob]

Has anyother bone material been found of these two dinosaurs?

[Down under fossil hunter]

Relatively complete specimens of both have been discovered.

[Regg Cato]

My tentative observation would be that it's most likely Deltadromeus; I have the original descriptions of both IIRC, I'll have to check them when i get home.

[Down under fossil hunter]

Cheers, let me know once you have checked them.

[Axelorox]

As I understand it, Deltadromeus and Bahariasaurus were contemporaries. It is possible that they are synonymous. No skull material has been found for either, so it's not possible to label any teeth as certainly belonging to either genus.

[Regg Cato]

Axelorox is right; hence it's not really possible to confidently assign teeth to a taxon for which there are no officially identified teeth lol.

It's been proposed that Bahariasaurus and Deltadromeus are congeneric, but I'd suggest based on comparison of the pubis that this isn't likely:

A: Pubis of Bahariasaurus ingens (from Rauhut, 1995); B: Distal pubis of Deltadromeus agilis (from Sereno et al. 1996).

Edited July 10, 2012 by Regg Cato

[siteseer]

It seems the only people confidently identifying teeth like those are people trying to sell them.

One reason you would see reputable dealers offering teeth with both names is because they got talked into it by other dealers or collectors who may have been talked into it by other dealers/collectors. Buyer beware. Every fossil collector wants a name for every tooth or shell but many times there isn't one yet. For some fossils that name may not come in a lifetime.

I am just wondering if you guys can help me, I have been collecting dinosaur teeth for several years now and have always been fascinated by them.

I am aware of Deltadromeus and Bahariasaurus and am equally aware that no skull material has been recovered from either species which is where my question comes from...... Are they the same thing? If you have a 3 inch theropod tooth from the Kem Kem that is neither Spinosaurus or Carcharodontosaurus then what is it?

Why do more and more reputable dealers list teeth belonging to both species?

I have obtained some of the better quality examples and to me they look like an inflated Carcharodontosaurus tooth.

I would be interested in all opinions.

Cheers

[Down under fossil hunter]

It seems the only people confidently identifying teeth like those are people trying to sell them.

One reason you would see reputable dealers offering teeth with both names is because they got talked into it by other dealers or collectors who may have been talked into it by other dealers/collectors. Buyer beware. Every fossil collector wants a name for every tooth or shell but many times there isn't one yet. For some fossils that name may not come in a lifetime.

Well said, buyer beware is critical when it comes to purchasing fossil specimens.

At the end of the day unidentified specimens rarely fetch the same price and also lack some of the appeal that a positively identified tooth carries.

[Boesse]

Thanks, Siteseer - that's exactly what I came to say. Bahariasaurus isn't known by much, and the type specimen was destroyed by an allied bombing run which destroyed the museum it was housed in (along with the Spinosaurus type). As far as I know, the skeleton of Deltadromeus hasn't really been described in detail anyway, and as someone else above has pointed out, the two may even be synonymous (in fact, Sereno took one of the referred specimens of Bahariasaurus and reidentified it as Deltadromeus).

The point being, it could be either taxon, or it could be neither. We just don't really have the fossils yet, and anyone selling these things with "concrete" identifications is just pulling it out of their ###### to make a successful sale. That's besides the point that dinosaur teeth are not by any means as identifiable as land mammal teeth - dinosaur teeth are generally fairly conservative in their morphology and difficult to identify when not sticking out of a skull. Toothed cetaceans - one of the groups I work on - suffer from the same problem. Some dino paleontologists who like teeth get a little jealous of what land mammal paleontologists can do with a pile of teeth (...as do I, for that matter).

EDIT: The picture below shows the known bones of Deltadromeus, which is why it's totally laughable that people try to identify teeth to this taxon:

Edited July 11, 2012 by Boesse

[Regg Cato]

Good points; people like to know what they're buying, and most casual collectors may like to have that information prepackaged for them on a nice display card...regardless of whether or not it's accurate or verifiable.

[Carcharodontosaurus]

Not only has the skull of Deltadromeus not been found, studies also suggest that it is more closely related to Limusaurus than the other ceratosaurs. Since Limusaurus was a herbivore, it isn't implausible to think that Deltadromeus was a herbivore as well. It would make a lot of sense too, with all of those giant predators running around.

EDIT: Here is the undescribed giant predator: http://theropoda.blo...saurus-and.html

Edited July 21, 2012 by Carcharodontosaurus