Found a contortus today.

[Shellseeker]

Today, I hunted for my 3rd time in June.. Once every 3 days is not bad, but I will be traveling North for 3 of the next 5 weeks... It will be more difficult to get out 10 times in June or July, so I make the most of every opportunity.  It is also good exercise and I also need that...

 

When I first started hunting,  I would occasionally find a P. contortus.  They were relatively rare in my sections of the Peace River. Every one I found , I would evaluate as aduncus or contortus.  They looked like this  and were almost always smaller than the numerous lemon,  bull and dusky  in the Peace River.. This was one of my best and has some colors. Most shark teeth in the Peace river are black blades with black roots. Also, this one has its serrations.  Because it is Miocene Era, contortus teeth are generally worn smooth.

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So, along with many other interesting fossils,  I found a Physogaleus contortus while hunting today at a site that has more Miocene material than others I frequent. It is a pretty tooth, so I wanted to share..

 

 

So this makes me wonder if ALL 3 of the teeth I pictured above are indeed Physogaleus contortus and , if so, why did it take so long for me to meet the robust version of P. contortus?

 

Maybe , in order to grow larger teeth,  a shark needed to live longer and grow larger by eating more... and have less competition from Megs, GWs, Makos, Hemis,  etc

Could be other causes,  comments always appreciated,,   Jack

 

[JamieLynn]

oooohhh,... gorgeous!

[digit]

Your second photo down of the more slim tooth with the long slender twisted crown matches my concept of P. contortus. Your recent "robust" find kind of clashes with my contortus concept. The tooth seems too large and robust and the serrations seem more coarse than I'm used to. It is certainly too large for G. aduncus and the tip is not prominently bent to the distal side as is characteristic for this species. The serrations on P. contortus seem to be very fine or nearly absent toward the slender tip of the crown.

 

Odd teeth like this that don't fit squarely into the "It's definitely a...." categories always seem to dissolve any certainty I have at shark tooth ID but they do provide a good source for drilling down into the ID features and learning what is really important. I'll see if I can get a reply from my shark tooth experts and hear what they have to say about this tooth. Meanwhile, this is always a good page to either elucidate or confuse yourself on these types of shark teeth:

 

https://www.fossilguy.com/gallery/vert/fish-shark/galeocerdo/galeocerdo.htm

 

 

Cheers.

 

-Ken

[Shellseeker]

2 hours ago, JamieLynn said:

oooohhh,... gorgeous!

Your response is why I chose to post a single small shark tooth that I had seen versions of previously... I am making excellent finds (Megs, Tridactly horse, mammal ungual, whale petrosal) in close proximity spots but chose to dig where I am finding a few colorful, perfect shark teeth in almost perfect condition. I was digging in a layer of limestone, pebble rock, clay that was hard to pry into but crumbled in the sieve. This tooth sat in that protecting mixture for a couple of million years, just waiting for me to pay attention.

Just had to share..  Jack

[Meganeura]

9 minutes ago, Shellseeker said:

Your response is why I chose to post a single small shark tooth that I had seen versions of previously... I am making excellent finds (Megs, Tridactly horse, mammal ungual, whale petrosal) in close proximity spots but chose to dig where I am finding a few colorful, perfect shark teeth in almost perfect condition. I was digging in a layer of limestone, pebble rock, clay that was hard to pry into but crumbled in the sieve. This tooth sat in that protecting mixture for a couple of million years, just waiting for me to pay attention.

Just had to share..  Jack

Spots like that are so few and far between - they’re so very worth digging through!

[Shellseeker]

1 hour ago, digit said:

Your second photo down of the more slim tooth with the long slender twisted crown matches my concept of P. contortus. Your recent "robust" find kind of clashes with my contortus concept. The tooth seems too large and robust and the serrations seem more coarse than I'm used to. It is certainly too large for G. aduncus and the tip is not prominently bent to the distal side as is characteristic for this species. The serrations on P. contortus seem to be very fine or nearly absent toward the slender tip of the crown.

 

Odd teeth like this that don't fit squarely into the "It's definitely a...." categories always seem to dissolve any certainty I have at shark tooth ID but they do provide a good source for drilling down into the ID features and learning what is really important. I'll see if I can get a reply from my shark tooth experts and hear what they have to say about this tooth. Meanwhile, this is always a good page to either elucidate or confuse yourself on these types of shark teeth:

https://www.fossilguy.com/gallery/vert/fish-shark/galeocerdo/galeocerdo.htm       Cheers. -Ken

Thanks , Ken.. A great link from Fossilguy...  I like his desire to clarify..

Note that you and I were in close proximity the day I found the 2nd tooth.  I think you were looking for matrix to check for cookie_cutter teeth.  This is exactly , along with the 1st tooth above, what I believed P. contortus teeth looked like:  Not robust, gracile serrations from a small 9 foot shark.

Not the 1st time I have found a similar.  It shows up in my early Pliocene location also..  These larger , more robust "Contortus teeth confuse me.. I fully endorse getting the shark tooth experts to comment on my confusion...

[Meganeura]

I’d like to add I personally probably would’ve marked the third tooth there as a G. Cuvier. The crown doesn’t seem quite twisted enough, and the serrations to prominent, to be P. Contortus.

[Shellseeker]

8 minutes ago, Meganeura said:

I’d like to add I personally probably would’ve marked the third tooth there as a G. Cuvier. The crown doesn’t seem quite twisted enough, and the serrations to prominent, to be P. Contortus.

When I first starting seeing these , I attributed them to a rather odd G. cuvier.. now I wonder if they might be transitional teeth..

[digit]

Yup. I lean toward a more gracile G. cuvier than a robust P. contortus but I see elements of both in this tooth which is what makes it interesting. Teeth that stay in their lane and a prototypical of their species are nice in that it gives humans a warm fuzzy feeling that they can place order upon nature and pigeonhole lifeforms into discrete "species". The specimens that blur the lines and trend toward the gray area between our definite forms are always more interesting (if not immediately satisfying). They cause us do check and double-check our distinctive features that we are using to define one species from the other. In the end (if we are lucky) we'll learn something for our time spent scratch our heads and consulting references in print, in person, or online. If we succeed and are able to refine the features that help us categorize nature then they may be ultimately the most satisfying finds. 

 

 

Cheers.

 

-Ken

 

P.S.: I remember that trip many years back collecting matrix from smaller waterways trying to understand the secret of why Isistius triangulus teeth only seem to appear in one locality in all of Florida. One potential theory was that they were so delicate that larger waterways like the Peace would simply grind them to dust and that they might appear in any small creek. I checked several smaller waterways but still the mystery of what makes Cookiecutter Creek so unique is elusive.

[Meganeura]

9 minutes ago, Shellseeker said:

When I first starting seeing these , I attributed them to a rather odd G. cuvier.. now I wonder if they might be transitional teeth..

Hmm - did P. Contortus transition to G. Cuvier? I’m not sure how different genuses are distinguished - but wouldn’t that imply Physagoleus and Galeocerdo are the same or very closely related genuses?

[Shellseeker]

30 minutes ago, Meganeura said:

Hmm - did P. Contortus transition to G. Cuvier? I’m not sure how different genuses are distinguished - but wouldn’t that imply Physagoleus and Galeocerdo are the same or very closely related genuses?

I certainly don't have a clue... I am suggesting a possibility  and you are looking for conclusions that could only be answered after years of scientific evaluation by real experts...

How does a Hastalis transition to a GW   ...

 

[ThePhysicist]

3 hours ago, Shellseeker said:

When I first starting seeing these , I attributed them to a rather odd G. cuvier.. now I wonder if they might be transitional teeth..

 

3 hours ago, Meganeura said:

Hmm - did P. Contortus transition to G. Cuvier? I’m not sure how different genuses are distinguished - but wouldn’t that imply Physagoleus and Galeocerdo are the same or very closely related genuses?

Galeocerdo and Physogaleus are known from the early Eocene onwards, and P. contortus from the Miocene. This precludes P. contortus from being a transitional species between Physogaleus and Galeocerdo, should they be considered distinct genera. Also, the plural of genus is "genera." 

[Meganeura]

14 minutes ago, ThePhysicist said:

 

Galeocerdo and Physogaleus are known from the early Eocene onwards, and P. contortus from the Miocene. This precludes P. contortus from being a transitional species between Physogaleus and Galeocerdo, should they be considered distinct genera. Also, the plural of genus is "genera." 

Genera - noted! And that makes sense - so what could be the case for a tooth like this?

[bthemoose]

Some have postulated that Galeocerdo aduncus and Physogaleus contortus could be the same shark, with aduncus representing the upper teeth and contortus the lowers. Here are a couple of interesting prior threads on this:

 

 

[ThePhysicist]

2 hours ago, Meganeura said:

Genera - noted! And that makes sense - so what could be the case for a tooth like this?

If you're referring to the 3rd tooth found yesterday, I lean towards G. cuvier. I note that it has complex serrations, does anyone have a clear example of Physogaleus with complex serrations? If not, they could be a useful distinguishing feature between later species of Galeocerdo (e.g. G. cuvier, G. aduncus) and Physogaleus. 

 

[Family Fun]

Very interesting thread, thanks for posting Jack!

[Shellseeker]

2 hours ago, bthemoose said:

Some have postulated that Galeocerdo aduncus and Physogaleus contortus could be the same shark, with aduncus representing the upper teeth and contortus the lowers. Here are a couple of interesting prior threads on this:

 

Thank you. I think you may have noticed my lack of understanding of the history in the renaming of "contortus"  and the details of that history.  You are what I choose to call a "lifesaver"

 

Having reviewed the 2 articles, I now have view that there may be nuances on scientists evaluate different types of Tiger Shark teeth. Unless forced,  I tend towards the easier path on how to differentiate.  In this case, I learned to differentiate based on the curvature or lack thereof , of the blade. One was aduncus , the other more contorted one, was Contortus.  I did not pay much attention to cuvier.  Who would mistake an Aduncus or Cortortus for cuvier (or so I thought)?  Thanks for the education.

[Shellseeker]

52 minutes ago, ThePhysicist said:

If you're referring to the 3rd tooth found yesterday, I lean towards G. cuvier. I note that it has complex serrations, does anyone have a clear example of Physogaleus with complex serrations? If not, they could be a useful distinguishing feature between later species of Galeocerdo (e.g. G. cuvier, G. aduncus) and Physogaleus.

 

I find your posts informative.  Thanks for providing your expertise.  I had a more simplistic need and simplistic answer. If the blade of a small Tiger Shark tooth curved,  then it meant Contortus to me.  I had no concepts around "complex serrations" Given my 1st tooth which I believe has a curved blade and some type of serrations,  does it qualify as "complex serrations"?

 

Here is a photo I took of of teeth found at a Blancan site.. it was there, years ago that I was starting to see some blade curvature on teeth that I had understood to be G. cuvier.  Large G. cuvier and Bull Shark teeth dominate the site. Do you believe that some G. cuvier can have some curvature of the blade ? (not necessarily the same blade curvature that P. contortus posess.)

 

I was attempting to get an expert to identify my tooth from yesterday.  You qualify.  Thank you. I will label it as G. cuvier.   Jack

 

[Meganeura]

1 hour ago, ThePhysicist said:

If you're referring to the 3rd tooth found yesterday, I lean towards G. cuvier. I note that it has complex serrations, does anyone have a clear example of Physogaleus with complex serrations? If not, they could be a useful distinguishing feature between later species of Galeocerdo (e.g. G. cuvier, G. aduncus) and Physogaleus. 

 

That was my thought - I had forgotten they were called “complex” serrations - but that’s what had made me lean G. cuvier!

[Meganeura]

50 minutes ago, Shellseeker said:

I find your posts informative.  Thanks for providing your expertise.  I had a more simplistic need and simplistic answer. If the blade of a small Tiger Shark tooth curved,  then it meant Contortus to me.  I had no concepts around "complex serrations" Given my 1st tooth which I believe has a curved blade and some type of serrations,  does it qualify as "complex serrations"?

 

Here is a photo I took of of teeth found at a Blancan site.. it was there, years ago that I was starting to see some blade curvature on teeth that I had understood to be G. cuvier.  Large G. cuvier and Bull Shark teeth dominate the site. Do you believe that some G. cuvier can have some curvature of the blade ? (not necessarily the same blade curvature that P. contortus posess.)

 

I was attempting to get an expert to identify my tooth from yesterday.  You qualify.  Thank you. I will label it as G. cuvier.   Jack

 

Complex serrations are (to my understanding) - serrated serrations. Serrations on serrations. Which G. Cuvier teeth absolutely have. 

[Shellseeker]

1 hour ago, Meganeura said:

Complex serrations are (to my understanding) - serrated serrations. Serrations on serrations. Which G. Cuvier teeth absolutely have. 

Pictures are worth a thousand words...

yields...

 

My tooth,

Never realized that they were there... On a lot of cuviers, missing or worn off..

[Meganeura]

8 hours ago, Shellseeker said:

Pictures are worth a thousand words...

yields...

 

My tooth,

Never realized that they were there... On a lot of cuviers, missing or worn off..

Quite prominent on a tooth like this Pathological G. Cuvier I found:

 

[Al Dente]

23 hours ago, Meganeura said:

Hmm - did P. Contortus transition to G. Cuvier?

Galeocerdo cuvier probably evolved from Galeocerdo mayumbensis which probably evolved from Galeocerdo eaglesomei.

[Al Dente]

17 hours ago, ThePhysicist said:

I note that it has complex serrations, does anyone have a clear example of Physogaleus with complex serrations? If not, they could be a useful distinguishing feature between later species of Galeocerdo (e.g. G. cuvier, G. aduncus) and Physogaleus. 

Physogaleus contortus teeth are highly variable, possible due to gender difference and age difference. They will range from simple small serrations to large complex serrations. Here are two from the late Oligocene/early Miocene Belgrade Formation from NC. My mid Miocene Pungo River Formation teeth show the same variation.

 

 

[Shellseeker]

10 hours ago, Al Dente said:

Physogaleus contortus teeth are highly variable, possible due to gender difference and age difference. They will range from simple small serrations to large complex serrations. Here are two from the late Oligocene/early Miocene Belgrade Formation from NC. My mid Miocene Pungo River Formation teeth show the same variation.

 

 

Thank you for the explanation.

I was getting more confused over time about the what species to assign to some of the larger Tiger shark teeth I was finding. It seemed that some teeth had characteristics of both cuvier and contortus. The teeth confusing me looked a lot like your tooth above on the left.  I thought it was a simple question and there might be a simple answer. Certainly , the answer is complex, not simple,  but I can live with that...

 

I am glad that I opened this thread, because it exposes a number of issues that I had not considered,  and I believe many other TFF members were in the same boat as I.   I'll consider those issues as I (hopefully) find more of these teeth like yours on the left. Jack