Shark Teeth from Post Oak Creek

[Chelsie]

I’d like for my Post Oak Creek collection identified (specifically the shark teeth), but I can’t find much information online about the species of shark whose teeth are found here (Post Oak Creek in Sherman, Texas). When I HAVE come across general information about the creek and other peoples findings online, there aren’t any pictures of the teeth or nobody else knows exactly what they have. It’s also hard to tell if I’m grouping them correctly, so I apologize if I’m mixing some species together. The longer teeth have very similar characteristics, but greatly differ in size. And the only teeth that I HAVE been able to identify are the ptychodus teeth (not pictured), but only because they’re so unusual in appearance. 

 

Excuse the quality of the images. I don’t feel like setting up my camera right now, but I do plan on taking clearer images once I’ve correctly identified each specimen. 

[bthemoose]

The first three smaller ones look potentially like Cretodus teeth to me, along with the largest tooth in the last group, though that might also be Cretalamna. The rest in that group look like goblins—Scapanorhynchus—possibly mixed with sand tigers like Carcharias but I’m not sure. The other two teeth are crow sharks—Squalicorax.

Edited January 22, 2023 by bthemoose

[Chelsie]

55 minutes ago, bthemoose said:

The first three smaller ones look potentially like Cretodus teeth to me, along with the largest tooth in the last group, though that might also be Cretalamna.

So, these ones look like Cretodus? Except the largest one could possibly be Cretalamna instead?

[bthemoose]

Thanks for the additional photo. The larger one looks like Cretalamna sp.

 

The shapes of the roots and lingual protuberances on the the other three remind me of Cretodus (and the larger of those three appears to have folds/wrinkles in the enamel which Cretodus does too too), but I’m less familiar with Cretodus posteriors so these might also be something else.

 

@ThePhysicist is much better at teeth from there than I am.

[ThePhysicist]

Cretalamna and Cretodus have very similar tooth designs, so they are easy to confuse. One distinguishing feature of Cretodus is basal ridges "costulae," though in POC, they can be weathered and hard to see, especially if they aren't that prominent to begin with (they're more visible on the lingual face). Cretodus also has more pointed, narrow cusplets compared to Cretalamna. 

 

 

Average Cretodus anterior (L), and a large Cretalamna anterior (R) (by large I mean one of the largest Cretalamna teeth I've seen anywhere, certainly from POC). The remaining cusplet on the Cretalamna is not broken.

 

 

So about the biggest tooth, I say it's Cretodus. But I'd like to see a side-on view, and a length measurement - looks like it's more than 1.5 inches. Can you see any ridges on it?

 

I agree with @bthemoose that the other teeth in your hand are posterior Cretodus. 

 

The teeth in your third pic are crow sharks. If it has serrations and/or notched, then it's Squalicorax:

 

The remaining teeth in your fourth pic excluding the largest are probably Scapanorhynchus - goblin sharks. Most of the Cretaceous sand tigers I've seen from NTX are very small, and I haven't seen any convincing ones in POC... yet.

 

4 hours ago, Chelsie said:

but I can’t find much information online about the species of shark whose teeth are found here (Post Oak Creek in Sherman, Texas)

I have considered making a "guide" to POC shark teeth since it's a semi-popular destination, but I don't know how much interest/use there would be for it.

[Chelsie]

29 minutes ago, ThePhysicist said:

So about the biggest tooth, I say it's Cretodus. But I'd like to see a side-on view, and a length measurement - looks like it's more than 1.5 inches. Can you see any ridges on it?

Do these images help? I’d say there’s ridges, though I’m not entirely sure what I’m looking for. About the length, it looks to be approximately 1.5 inches.

[ThePhysicist]

7 minutes ago, Chelsie said:

Do these images help? I’d say there’s ridges, though I’m not entirely sure what I’m looking for. About the length, it looks to be approximately 1.5 inches.

Perfect, this is 100% Cretodus, nice!

[Chelsie]

2 hours ago, ThePhysicist said:

I have considered making a "guide" to POC shark teeth since it's a semi-popular destination, but I don't know how much interest/use there would be for it.

I say go for it! I’m sure I’m not the only one who’d appreciate the information, especially in the coming years. The city announced that a new 160 acre “fossil park” and recreation area is in the works that is centered around Post Oak Creek and making it more accessible to the public. I live around the corner from the popular access point by Travis Street bridge. They’re currently reconstructing the bridge as part of the project. Tons of people will likely be seeking information about the shark teeth specifically, since that’s what the creek is most popular for. 

[Jared C]

20 hours ago, ThePhysicist said:

I have considered making a "guide" to POC shark teeth since it's a semi-popular destination, but I don't know how much interest/use there would be for it.

I'd buy one, it'd be useful for folks who hunt the eagle ford and atco in general in my opinion