Need Help For A Strange Megalodon

[Sélacien34]

If this tooth is in fact pathologic, and pathologies are produced by damage tot he jaws; then how is it that so many of these teeth over a range of species look so much alike? The odds of two pathologic teeth looking almost identical even from the same shark must be astronomical. But from different species?

Just my thoughts.

Hello Don, would you still have your auriculatus patho/parasymphyseal ? Could you please take a good picture of the lingual and labial view in vertical position to see better the shape of the root, like mine.

Edited April 20, 2014 by Sélacien34

[siteseer]

Don,

I agree with you. The general consistency of the root shape and the small size especially makes me think more symphyseal than pathologic. If they were pathologic, we should see at least a few teeth at least three inches high. Also, since Otodus has been demonstrated to have had symphyseals (in the broad sense to include parasymphyseals) and so has Parotodus, it follows that the sister taxon of Parotodus could also have symphyseals. In fact, I think we should expect it but also expect it to be a rare expression as it is in Parotodus.

As for the narrowness of the teeth, I would say that megalodon teeth are a broader-crowned species so the symphyseals would be expected to look broad relative to those of narrower-crowned species. I'm not sure if the straightness of the crown is significant in identifying it as a symphyseal. It could be an indicator but not necessarily a deal-breaker. I think the root shape is very significant especially when many suspected symphyseals have the same general shape.

It would be interesting to get David Ward's opinion on these teeth.

Jess

If this tooth is in fact pathologic, and pathologies are produced by damage tot he jaws; then how is it that so many of these teeth over a range of species look so much alike? The odds of two pathologic teeth looking almost identical even from the same shark must be astronomical. But from different species?

Just my thoughts.

[Sélacien34]

Here we have potential bigger symphyseal teeth from an adult, the shape of the roots are less bulbous and better defined, we saw some reasons that could explain that, the crowns are higher, but they seem to show a common characteristic, serrations that are erased on the base of one edge.

Parotodus, it follows that the sister taxon of Parotodus could also have symphyseals.

this is an interesting argument that I will add, i would try to ask their opinion to M. Siversson and D. Ward.

As for the narrowness of the teeth, I would say that megalodon teeth are a broader-crowned species so the symphyseals would be expected to look broad relative to those of narrower-crowned species. I'm not sure if the straightness of the crown is significant in identifying it as a symphyseal. It could be an indicator but not necessarily a deal-breaker. I think the root shape is very significant especially when many suspected symphyseals have the same general shape.

That what i said among the arguments in my last mail adressed to the Dr Kent, i'm waiting for his answer.

....some of them belong to different species from the lineage, with crowns more or less wide, with specific differences bound to the different species...On the pictures, some specimens of the teeth belonging to the most members of Otondontidae. When we observe those belonging to the first representative of the lineage and those of his successors, it seems that the common points persist...Nevertheless, common characters seem to link these unusual teeth, particulary the shape of the roots and the crowns with one side where the serration become faint...

It would be useful to see pictures of the Ric from Don that show better the shape of the root.

[sixgill pete]

Here are 4 pics of my symphyseal auriculatus

[sixgill pete]

and here are 2 pics of a symphyseal megalodon, as ID'd by Marco

both of these teeth were posted in the ID section on here when I found them. They were ID'd by Marco and others as symphyseals.

[Sélacien34]

Thank you Don, i wanted to see it under this plan, to see the globality of the lingual face.

[Sélacien34]

Cretalamna appendiculata symphyseal and parasymphyseal teeth look the same

Edited April 27, 2014 by Sélacien34

[Sélacien34]

A second expert, one of the best about the otodontidae, has answered and he thinks that it is pathological teeth. About mine he said that his wide crown argues against it being a symphyseal/parasymphyseal tooth. He gave the exemple of Cretalamna, whose the symphyseals have a crown that is far less compressed than it is in laterals. Same with anacoracids, symphyseals do not have a wide crown.

Would it be impossible that the crowns of those teeth widen, in relation to the rest of the dentition , during the evolution of Otodontidae ? Can we compare Otodontidae to Anacoracidae or other different families for all caracteristics? These teeth are often identified as posterior teeth, and in this case , they are too compressed. Why these teeth are always small size and why no one has found any large tooth that has this type of roots and crowns? Pathology.

[DeloiVarden]

Interesting topic guys. I am not sold out on the O. Megalodon symphyseal theory yet, but here is a recent find of mine. Any thoughts?

[Carl]

That's a beauty of a pathology! I can see some lucky Muskogee finding that, lashing it to a shaft, and taking down a deer in style!

Edited January 9, 2015 by Carl

[DeloiVarden]

That is funny you say that Carl, because when I found it on the bottom of the river my first thought was "sweet point". I am leaning toward pathology because of the hundreds of thousands of megs I have found, I have only found a few pathological examples that could be mistaken as para or symphs. For those that believe the megalodon could have had teeth in this position, I just don't think the numbers support it. I also know a gentleman who recovered most of an associated set of megalodon in Bone Valley, and there were no teeth of this position. Maybe they missed them and maybe less are lost due to the somewhat protected position in the jaw, but it will take many more examples to convince me

[Coco]

For me too it is about a pathological tooth. The root is "far too much closed" to be normal. The shape of roots doesn't change a lot according to the location of teeth in shark jaw. Only the crown changes.

Coco

[siteseer]

I disagree that the width of the tooth significant. In the mouth of a megalodon, the width of that little tooth takes up little space even if two files were present. I'm not sure how comparing it to Cretolamna or anacoracids provides any kind of strong evidence pro or con. It's interesting to compare them but these taxa are also quite distinct from each other and well-separated from each other in geologic time.

A second expert, one of the best about the otodontidae, has answered and he thinks that it is pathological teeth. About mine he said that his wide crown argues against it being a symphyseal/parasymphyseal tooth. He gave the exemple of Cretalamna, whose the symphyseals have a crown that is far less compressed than it is in laterals. Same with anacoracids, symphyseals do not have a wide crown.

Would it be impossible that the crowns of those teeth widen, in relation to the rest of the dentition , during the evolution of Otodontidae ? Can we compare Otodontidae to Anacoracidae or other different families for all caracteristics? These teeth are often identified as posterior teeth, and in this case , they are too compressed. Why these teeth are always small size and why no one has found any large tooth that has this type of roots and crowns? Pathology.

[siteseer]

Jason,

Correct me if I'm wrong but the megalodon teeth you collect tend to be Late Miocene to possibly Early Pliocene in age. It would be a super-rare genetic expression of an ancestor by that time. On top of that the chance that the tooth would survive as a fossil and be collected by someone who would recognize it as unusual would be very slim. Selacien34's tooth is Early-Middle Miocene in age - a time when it would have been a little more likely that a symphyseal would turn up. The Bone Valley dentition is also no older than Late Miocene age. The dentition is super-rare enough but expecting it to also include a parasymphyseal tooth wouldn't be realistic.

Consider that whales evolved from a branch of land mammals. From the Early to Middle Eocene whales had feet that became flippers but their hind feet began to disappear. Some Late Eocene whales still had legs that were nearly fully formed but no longer useful as the animals were fully-aquatic by that time. Move to the present. It's very rare to see but a few whales of different species have been seen with partially-developed hind limbs. There is a dolphin at a park in Japan that has fins toward the end of its tail.

The thing that keeps me thinking that teeth like that are parasymphseals is that they are always small. That cool tooth you show might be one and would be the largest one I have seen. You don't see 3-5 inch teeth in the same shape as Selacien34's tooth. It would be a super-rare to find a Parotodus parasymphyseal. We know that Parotodus had them occasionally because an Early Miocene partial dentition was found in Australia and it had at least one tooth of that form. Parotodus and Carcharocles descended from Otodus and if both Otodus and Parotodus had parasymphyseals, then we would expect Carcharocles to them as well even if it became a file more rarely present across Middle Eocene, Oligocene, Miocene. It's not that anyone is certain that Carcharocles had them. It's just that it would seem unusual that it never had them given its ancestry and closest relative.

That is funny you say that Carl, because when I found it on the bottom of the river my first thought was "sweet point". I am leaning toward pathology because of the hundreds of thousands of megs I have found, I have only found a few pathological examples that could be mistaken as para or symphs. For those that believe the megalodon could have had teeth in this position, I just don't think the numbers support it. I also know a gentleman who recovered most of an associated set of megalodon in Bone Valley, and there were no teeth of this position. Maybe they missed them and maybe less are lost due to the somewhat protected position in the jaw, but it will take many more examples to convince me

[DeloiVarden]

Jason,

Correct me if I'm wrong but the megalodon teeth you collect tend to be Late Miocene to possibly Early Pliocene in age. It would be a super-rare genetic expression of an ancestor by that time. On top of that the chance that the tooth would survive as a fossil and be collected by someone who would recognize it as unusual would be very slim. Selacien34's tooth is Early-Middle Miocene in age - a time when it would have been a little more likely that a symphyseal would turn up. The Bone Valley dentition is also no older than Late Miocene age. The dentition is super-rare enough but expecting it to also include a parasymphyseal tooth wouldn't be realistic.

Consider that whales evolved from a branch of land mammals. From the Early to Middle Eocene whales had feet that became flippers but their hind feet began to disappear. Some Late Eocene whales still had legs that were nearly fully formed but no longer useful as the animals were fully-aquatic by that time. Move to the present. It's very rare to see but a few whales of different species have been seen with partially-developed hind limbs. There is a dolphin at a park in Japan that has fins toward the end of its tail.

The thing that keeps me thinking that teeth like that are parasymphseals is that they are always small. That cool tooth you show might be one and would be the largest one I have seen. You don't see 3-5 inch teeth in the same shape as Selacien34's tooth. It would be a super-rare to find a Parotodus parasymphyseal. We know that Parotodus had them occasionally because an Early Miocene partial dentition was found in Australia and it had at least one tooth of that form. Parotodus and Carcharocles descended from Otodus and if both Otodus and Parotodus had parasymphyseals, then we would expect Carcharocles to them as well even if it became a file more rarely present across Middle Eocene, Oligocene, Miocene. It's not that anyone is certain that Carcharocles had them. It's just that it would seem unusual that it never had them given its ancestry and closest relative.

Thanks Siteseer. You make some good points. The particular spot has many megalodon, but I have found almost as many chubutensis, and even a few angustidens, and early narrow form mako. So I believe strongly that the presence of such teeth point to an earlier Miocene layer. I agree that a protected position such as a symphyseal could be missing from the one associated set, but given the number of shark teeth I have found in this one location, I still don't believe the unproportionally low ratio of such teeth don't help the pro symphseal case. I have also hunted oligocene exposures in ditches for years and have also found very few pathological teeth that could even be mistaken as a symphyseal. Could there have been a smaller, isolated population of symphyseal bearing megalodon? Maybe, but I am just not there yet. I don't think there is enough evidence to go either way, but there is certainly enough to fuel a great discussion. Thanks for being a part of it. I would suggest folks keep posting pictures of there finds so that we can continue to gain a clearer picture! For size reference, the pictured example in my post above is 39mm. If it is a symphyseal, it came from a very large shark!

Edited January 11, 2015 by DeloiVarden

[DeloiVarden]

Here is one for the pro camp.