Shark Tooth Fragment From North Texas Hunt

[BobWill]

Dallas Paleontological Society hosted a field trip to collect the Pennsylvanian Graham Formation Saturday. I found this partial Orodus variabilis. I'm going back soon to find the rest of it

The scale is in mm

Labial View

Lingual View

Top

[sharko69]

Nice find! Congratulations.

[DinoMike]

That is a great find! Pennsylvanian shark teeth are very interesting, not much like what we're used to seeing as "shark."

[Shellseeker]

Love learning something new.. From what I can find on the Net -- you got most of it and the colors are great! Thanks for sharing.

[Fossildude19]

Wow, the paleozoic shark teeth keep coming!

Excellent find, Bob.

Thanks for showing it to us.
Regards,

[Carl]

LOVE them Paleozoic shark teeth!

[eboe101]

Great tooth! However I think you have a

Agassizodus tooth, which is even less common. The orodus teeth tend to be more apically compressed while Agassizodus is more bulbous.

[BobWill]

Thanks eboe. Mark Mckinzie's new book shows Agassizodus variabilis has been found at one of the Bridgeport sites but not in the Finis Shale so we can add that to the fauna list for Jacksboro. There was only a picture of an orodus from Jacksboro for comparison and that was the closest thing to mine but I can see what you mean about the different overall shape. He does show one from the Ada Brick Plant in Oklahoma that is shaped more like mine but labeled it orodus too. I will see him Wednesday so I can ask about it.

[JimB88]

Great tooth!

[fossilized6s]

Beauty, Bob. Congrats!

[TNCollector]

That's a nice-un!

[BobWill]

I mentioned the suggestion from eobe about the ID in an email to Mark McKinzie and he sent me this:

Here is my take on Orodus versus Agassizodus. I have seen both teeth illustrated in old publications from the 1800’s and many of them look just alike to me. I have NEVER seen a good, recent (post 1970’s after cladistics analysis was introduced), scientific reference that distinguishes between the two. Like a lot of modern-day sharks, their dentitions consisted of hundreds of teeth in the mouth at any one time. And of course the tooth shape varies depending on its placement in the mouth (symphaseal versus lateral; anterior versus posterior, upper versus lower, etc). I wouldn’t be surprised if the two shark names turned out to be synonymous and the older genera name will take priority. But that will await some researcher actively working on it. The species name Orodus variabilis hints that there is “great variability” in the shape of the teeth (hence the name). Very few Paleozoic sharks are known from complete dentitions so there is a lot of similar tooth shapes given different names from the same geologic age but different geographic localities that probably belong to the same shark. I know most fossil collectors want a concrete ID but with Paleozoic sharks in particular there is a lot of “clean-up” research that needs to be addressed today. So the Fossil Forum guy could be right. Proving it one way or another with more than just a single illustrated tooth from an old publication is the hard part. Contrary to what everyone under 30 years old thinks, not every answer can be Googled!

[Carl]

I mentioned the suggestion from eobe about the ID in an email to Mark McKinzie and he sent me this:

Here is my take on Orodus versus Agassizodus. I have seen both teeth illustrated in old publications from the 1800’s and many of them look just alike to me. I have NEVER seen a good, recent (post 1970’s after cladistics analysis was introduced), scientific reference that distinguishes between the two. Like a lot of modern-day sharks, their dentitions consisted of hundreds of teeth in the mouth at any one time. And of course the tooth shape varies depending on its placement in the mouth (symphaseal versus lateral; anterior versus posterior, upper versus lower, etc). I wouldn’t be surprised if the two shark names turned out to be synonymous and the older genera name will take priority. But that will await some researcher actively working on it. The species name Orodus variabilis hints that there is “great variability” in the shape of the teeth (hence the name). Very few Paleozoic sharks are known from complete dentitions so there is a lot of similar tooth shapes given different names from the same geologic age but different geographic localities that probably belong to the same shark. I know most fossil collectors want a concrete ID but with Paleozoic sharks in particular there is a lot of “clean-up” research that needs to be addressed today. So the Fossil Forum guy could be right. Proving it one way or another with more than just a single illustrated tooth from an old publication is the hard part. Contrary to what everyone under 30 years old thinks, not every answer can be Googled!

OUTSTANDING RESPONSE!!!

[Darktooth]

Really nice find!