Russian Sand Tigers

[bthemoose]

I purchased some shark teeth recently, all or most of which appear to be sand tigers, from Russia and am hoping some folks on here might be able to help me identify them.

 

The information from the seller, who is in Russia but didn't collect these himself, is that these are Cretaceous teeth found in chalk deposits on the banks of the Don River, near Kalach-on-Don, Volgograd region, Russia. He doesn't have any more info or know the exact geologic layer. I haven't been able to find much information from searching online, but using the app Rockd, it does appear that the geology in the area around Kalach-on-Don is Late Cretaceous (see composite screenshots from the app below). Many of the teeth themselves also have remnant white chalky matrix on them and some have what appear to be calcite crystals on them. If anyone here knows more about the geology/stratigraphy of the area that you could share with me, that would be great!

 

 

Below are photos of the teeth. While the info above checks out, I have some suspicion that these teeth might be younger than Cretaceous in age. I may well be wrong about that, though, and would be happy to know either way if you think these look like Cretaceous teeth or if you think they're from a more recent time period. These are nice looking teeth that were reasonably priced, and I don't mind if they're younger; I'm just interested in trying to identify them.

 

I've tried to organize the teeth in the photos below into groups with similar characteristics. Please let me know if any additional photos would be helpful, and thanks in advance for any help you can provide!

 

Group 1: 

These all have lingual striations, except for the tooth on the far right, though that one's more worn and may have had them originally. The tooth fourth from the left/third from the right has very different coloration than all of the other teeth I acquired and reminds me of the coloration of teeth I've seen from Kazakhstan (perhaps it was accidentally mixed in?). You can't necessarily tell from the photos, but these all have very small lateral cusplets/nubs, one on each side.

 

 

Here are additional views on the leftmost tooth above, which is generally representative of the others. One reason I question whether these are Cretaceous in age is the striations on these remind me more of Striatolamia sp. teeth I've seen from the Paleocene and Eocene than Scapanorhynchus sp. teeth from the Cretaceous, which in my albeit limited experience have deeper/more prominent striations. The striations on these teeth also do not appear to extend onto the roots.

 

 

Group 2: 

These teeth are also lightly striated on the lingual side, which you can see more clearly in the second set of photos below detailing the leftmost tooth. These all have one lateral cusplet on each side of the cusp (more rounded on the two teeth on the right). My guess is these are the same species as the ones above, just different tooth positions. The tooth on the left in particular does remind of Scapanorhynchus sp. 

 

 

Here are more detailed views of the tooth on the left:

 

Group 3: 

The teeth below all lack striations; the preservation is quite good, so I don't think they ever had them. These teeth have fairly large lingual root protuberances. The first three teeth each have one sharp, but small lateral cusplet on each side. The two teeth on the right both have two lateral cusplets on each side.

 

 

Here are some more detailed photos of the leftmost tooth:

 

 

And here are some closer photos of the two teeth on the right, which have two lateral cusplets on each side:

 

 

Group 4: 

The two teeth below also lack striations and have one pointy cusplet on each side of their cusps (one of the cusplets is broken on the left tooth). I've separated these two out from the teeth above as the lingual protuberances aren't as large/prominent.

 

 

Group 5: 

These are somewhat smaller teeth that may be from the same species as teeth above. All three lack striations. The one in the middle has two cusplets on each side while the other two each have only one.

 

 

 

Group 6: 

These two teeth have more u-shaped roots and narrower cusps than the ones above. They lack striations and have one cusplet on each side of the cusp (though some are broken).

 

 

Group 7: 

This tooth has more triangular cusplets than the ones above and a more angular root. It lacks striations.

 

 

Group 8: 

The final tooth is a bit worn, but reminds me of the Cretaceous thresher, Paranomotodon sp.

 

[Gizmo]

My first impression is they all look like Paleocene teeth similar to those found at different spots on the Potomac river.  The similar appearance suggests they were found in the same sediments in Russia.

 

[bthemoose]

8 hours ago, Gizmo said:

My first impression is they all look like Paleocene teeth similar to those found at different spots on the Potomac river.  The similar appearance suggests they were found in the same sediments.

 

 

Thanks, @Gizmo. I also wondered about these potentially being Paleocene teeth due to similarities with what I find from the Aquia formation here in Maryland -- perhaps some Striatolamia striata and Jaekelotodus robustus, among others.

 

I'm not sure I understand the second part. Are you suggesting these look to you like they are actually from the Potomac or rather from a similar type of sediment? If the former, in hand, I can say these don't remind me of Maryland teeth I've found. These ones are significantly whiter vs. the typical grays from the Aquia formation, at least around Douglas Point and Purse State Park. While not dispositive on provenance, these ones also did arrive in a box from Russia. 

 

Here's a side-by-side photo with a typical Aquia tooth on the left.

 

[Gizmo]

 I meant they look like they come from the same sediments / location in Russia.

[bthemoose]

Mystery solved — turns out these are Eocene teeth from Kazakhstan!