Red Flags on Montana Dino Teeth

[Troodon]

I post this as a reminder to Dinosaur tooth collectors that the Kem Kem Beds is not the only place that you need to be careful when you are looking to buy teeth but offerings from the States can be problematic.   New collectors should to be especially mindful that sellers are not always accurate in what they are selling.  Best to ask us B4 you buy.

 

Here are a few examples:

A beautiful Tyrannosaur tooth is being offered and sold as Albertosaurus from the Judith River Formation of Montana.  Unfortunately this species is not described from this locality and currently only known from very late campanian, early maastrichtian deposits of the Horseshoe Canyon Formation in Alberta.   You cannot distinguish between species of Tyrannosaurid teeth from campanian deposits.  So this tooth is either a Daspletosaurus or Gorgosaurus tooth.   Best identified as Tyrannosaurid indet.

 

 

 

Aublysodon pre-max tooth is being offered from the Judith River of Montana.  Unfortunately this species is no longer considered valid and teeth of this morphology are assigned to other Tyrannosaurids.  In this formation, it's either a Daspletosaurus or Gorgosaurus tooth.  Nice tooth best identified as Tyrannosaurid indet.

 

 

An offering of a Nodosaurs tooth,  Edmontonia rugosidens from the Hell Creek Formation.  Unfortunately this species is not described from the Hell Creek Formation.  Currently only Denversaurus schlessmani is the only described Nodosaur from the Hell Creek/ Lance Formations.  Again a nice tooth.  Be aware that other Nodosaurs may exist in these localities and this tooth is best described as Nodosaurid indet. but until those discoveries are made calling it Denversaurus is acceptable. 

 

 

The Ceratopsian Leptoceratops gracilis is being offered from the Hell Creek Formation.  Again this species has not been described from this formation.   The teeth are however identical to those L. gracilis and should be identified as:  c.f. Leptoceratops gracilis. until we have a named species described.

 

 

Daspletosaurus tooth being offered from the Judith River Formation.   Similar comment as my first one.  You cannot distinguish between species of  Tyrannosaurid teeth from campanian deposits.  Either a Daspletosaurus or Gorgosaurus tooth.  Best identified as Tyrannosaurid indet.

[LordTrilobite]

Some consider Gorgosaurus to be synonymous with Albertosaurus. So in that case it would be less inaccurate. But yeah, it should be identified as Tyrannosaurid indet.

[Troodon]

7 minutes ago, LordTrilobite said:

Some consider Gorgosaurus to be synonymous with Albertosaurus. So in that case it would be less inaccurate. But yeah, it should be identified as Tyrannosaurid indet.

I don't see that in the scientific papers 

[LordTrilobite]

I think it might have fallen out of favour. I don't remember the names, but some scientists have labeled Gorgosaurus libratus as Albertosaurus libratus. So sadly I don't have a specific source on me. But it doesn't have that big an impact either way as both species are still valid.

[*THEO*]

From wikipedia -

"In 1913, paleontologist Charles H. Sternberg recovered another tyrannosaurid skeleton from the slightly older Dinosaur Park Formation in Alberta. Lawrence Lambe named this dinosaur Gorgosaurus libratus in 1914.^[22]Other specimens were later found in Alberta and the US state of Montana. Finding, largely due to a lack of good Albertosaurus skull material, no significant differences to separate the two taxa, Dale Russell declared the name Gorgosaurus a junior synonym of Albertosaurus, which had been named first, and G. libratus was renamed Albertosaurus libratus in 1970. A species distinction was maintained because of the age difference. This addition extended the temporal range of the genus Albertosaurus backwards by several million years and its geographic range southwards by hundreds of kilometres.^[1]

In 2003, Philip J. Currie, benefiting from much more extensive finds and a general increase in anatomical knowledge of theropods, compared several tyrannosaurid skulls and came to the conclusion that the two species are more distinct than previously thought. The decision to use one or two genera is rather arbitrary, as the two species are sister taxa, more closely related to each other than to any other species. Recognizing this, Currie nevertheless recommended that Albertosaurus and Gorgosaurus be retained as separate genera, as he concluded that they were no more similar than Daspletosaurus and Tyrannosaurus, which are almost always separated. In addition, several albertosaurine specimens have been recovered from Alaska and New Mexico, and Currie suggested that the Albertosaurus-Gorgosaurus situation may be clarified once these are described fully.^[14] Most authors have followed Currie's recommendation,^[2][4][23] but some have not."

[LordTrilobite]

Thanks Theo. That was indeed what I meant.

[SULLY]

That first tooth is good looking