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Ptychodus Id Quick Guide


Tony Eaton

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The folks from the Jackson School of Geology, Vertebrate Paleontology department at the University of Texas brought a Ptychodus rugosus specimen to Fossil Fest last weekend. It was an old specimen but perfect and HUGE! maybe 2-inches (55mm) wide. Regretting not getting a picture of it.

 

Can anyone put age ranges on those listed above? Sometimes sorting them out is a lot easier when you can eliminate those too young or too old for your local.

 

PS LSCHNELLE set up a great display that included those teeth from our local strata.

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Pics of Ptychodus teeth dentition with slightly out of focus larger tooth.  Also, age chart -  modified by me for Austin courtesy of Shawn Hamm's thesis. 

Screenshot_20161103-144436.jpg

20161126_164528.jpg

20161120_162415.jpg

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The UT students said the huge single Ptychodus tooth was not a trustworthy ID as P. Rugosus - even though they can be up to 80mm wide.  My understanding from Shawn Hamm's MS paper is that P. Rugosus has a bulbous and often offset from center crown which this tooth did not have.  This tooth looks more like a huge P. Marginalis because of the concentric circles. Or, if from England, it could be P. Polygyrus. 

 

The dentition is a harder ID.  I would guess that it is a very large P. Decurrens due to its bifurcating transverse ridges extending to marginal edge and due to its numerous fine ridges on the labial and lingual margins perpendicular to the transverse ridges.  

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Erose:  Hopefully, the colored chart gives you the age and formation ranges that were looking for on Central Texas Ptychodus teeth.

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  • 2 weeks later...
  • 1 year later...
On 11/26/2016 at 5:49 PM, LSCHNELLE said:

Pics of Ptychodus teeth dentition with slightly out of focus larger tooth.  Also, age chart -  modified by me for Austin courtesy of Shawn Hamm's thesis. 

Screenshot_20161103-144436.jpg   20161126_164528.jpg  20161120_162415.jpg

 

wow, incredible..., the Maximum you can find in a ptychodus-collectors life...

thanks for posting

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  • 9 months later...

Here's a Ptychodus tooth I recently found in a gravel bar in Austin TX, presumably from the late Santonian Ozan formation. I just heard back from renowned Ptychodus researcher Shawn Hamm, who said it was a P. martini. Certainly the largest, most well-preserved tooth in my collection.

as found.jpg

occlusalview.jpg

sideview.jpg

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Hi,

 

What a beauty !

 

Coco

----------------------
OUTIL POUR MESURER VOS FOSSILES : ici

Ma bibliothèque PDF 1 (Poissons et sélaciens récents & fossiles) : ici
Ma bibliothèque PDF 2 (Animaux vivants - sans poissons ni sélaciens) : ici
Mâchoires sélaciennes récentes : ici
Hétérodontiques et sélaciens : ici
Oeufs sélaciens récents : ici
Otolithes de poissons récents ! ici

Un Greg...

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Massive and gorgeous tooth! :)

And what a great thread this is, very useful and informative. 

Life's Good!

Tortoise Friend.

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  • 1 month later...

Truceburner - Flawless jumbo tooth.!!  I still don't have P. martini and P. rugosus in my Travis County collection.  And my largest (>25mm TW) teeth (except the pictured P. latissimus from the Atco member lag deposits) all have some apical wear flaw on the crown.  What are the dimensions of yours in mm?

P_latissimus091017.jpg

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@LSCHNELLE The specimen shown in my post above is 27mm wide and 22mm front to back. I don't know the crown height. Is crown height usually measured from the margin?

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3 hours ago, truceburner said:

@LSCHNELLE The specimen shown in my post above is 27mm wide and 22mm front to back. I don't know the crown height. Is crown height usually measured from the margin?

BTW - Large size tooth in excellent condition. Congrats.  I am jealous!  I don't normally hunt fossils on the east side of town.

You will need to look at the explanation in Shawn Hamm's thesis.  He will be coming out with an update soon.  Here is a pic showing how to measure of crown height. Sometimes, it would be from the edge if there is no marginal area. 

20190212_211415.jpg

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  • 3 weeks later...

Great read this has been very informative. I have quite a bit of small Hematite I haven't sorted yet. I will be checking for pieces that look like the pictures. I'm an indiscriminate rockhounder. I pick up whatever I like the looks of. Which is what led me on this journey. Thank you all for taking the time to put this resource together. 

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  • 10 months later...

The New Mexico Museum of Natural History has published a new Monogram by Shawn Hamm on ptychodus.  Right now I think the only way to order is to call them and order over the phone.   I haven't seen it yet, but I have one on the way!

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For one species to mourn the death of another is a new thing under the sun.
-Aldo Leopold
 

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Ramo:  I got mine on January 16th.  Your associated tooth Ptychodus anonymous find has been very helpful to me and it is on full display in Bulletin 81.

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On 11/26/2016 at 5:49 PM, LSCHNELLE said:

Pics of Ptychodus teeth dentition with slightly out of focus larger tooth.  Also, age chart -  modified by me for Austin courtesy of Shawn Hamm's thesis. 

 

20161126_164528.jpg 20161120_162415.jpg

 

On 12/20/2018 at 5:57 PM, truceburner said:

Here's a Ptychodus tooth I recently found in a gravel bar in Austin TX, presumably from the late Santonian Ozan formation. I just heard back from renowned Ptychodus researcher Shawn Hamm, who said it was a P. martini. Certainly the largest, most well-preserved tooth in my collection.

as found.jpg  occlusalview.jpg sideview.jpg

 

On 2/11/2019 at 3:11 PM, LSCHNELLE said:

Truceburner - Flawless jumbo tooth.!!  I still don't have P. martini and P. rugosus in my Travis County collection.  And my largest (>25mm TW) teeth (except the pictured P. latissimus from the Atco member lag deposits) all have some apical wear flaw on the crown.  What are the dimensions of yours in mm?

P_latissimus091017.jpg

 

On 2/12/2019 at 10:18 PM, LSCHNELLE said:

BTW - Large size tooth in excellent condition. Congrats.  I am jealous!  I don't normally hunt fossils on the east side of town.

You will need to look at the explanation in Shawn Hamm's thesis.  He will be coming out with an update soon.  Here is a pic showing how to measure of crown height. Sometimes, it would be from the edge if there is no marginal area. 

20190212_211415.jpg

Gorgeous teeth ! :envy::envy::envy:

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"On ne voit bien que par le coeur, l'essentiel est invisible pour les yeux." (Antoine de Saint-Exupéry)

"We only well see with the heart, the essential is invisible for the eyes."

 

In memory of Doren

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  • 3 weeks later...

Here is another topic those searching here may be interested in: 

 

 

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    Tim    VETERAN SHALE SPLITTER

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"In every walk with nature one receives far more than he seeks."
John Muir ~ ~ ~ ~   ><))))( *>  About Me      

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thank you so much for making this convenient guide,Tony!

Now I can identify the ptychodus tooth I found in a farm at Kansas as Ptychodus whipplei.

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  • 10 months later...

These are honestly beautiful. Geographically speaking I'm guessing they're mostly found in the southern region of North America?

 

I honestly would not have known at a glance that this was a tooth at all. Thanks so much for the guide.

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  • 2 months later...

Hey! Who is the expert in the matter. Can someone give a personal consultation? write to direct!:rolleyes:

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