Ptychodus Id Quick Guide

[Fossildude19]

12 minutes ago, RobinS87 said:

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

 

You may consider writing a Personal Message to Tony Eaton, the author of this topic. 

He hasn't been online here in over a year, however.  

[rocket]

just for showing, a very nice Ptychodus decurrens from middle turonian of Dortmund, nw-Germany, coming from the collection of a friend of mine

[LSCHNELLE]

3 hours ago, rocket said:

just for showing, a very nice Ptychodus decurrens from middle turonian of Dortmund, nw-Germany, coming from the collection of a friend of mine

Beautiful Ptychodus tooth.  What is the approximate tooth width and length? 

[rocket]

thanks, wide is around 40 mm

[rocket]

Another one, Ptychodus latissimus, wide is around 50 mm, lower Turonian, Dortmund

 

 

 

 

[LSCHNELLE]

Monster Ptychodus latissimus!  Beautiful! 

[rocket]

48 minutes ago, LSCHNELLE said:

Monster Ptychodus latissimus!  Beautiful! 

thanks, yes, it is a fantastic one. We stored it in a museum some years ago, perhaps someone will work on it one day. I thought about but never found the time...

[rwise]

Here are a couple of mine...looking to confirm IDs  ....Ptychodus decurrens??

 

 

 

 

And last one Ptychodus anonymus?????

 

 

 

 

 

 

Edited May 25, 2022 by rwise

[LSCHNELLE]

Nice teeth!  I would think Ptychodus latissimus for both.  Notes:  (1) see most recent tooth posted here before yours; (2) typically fewer ridges (six each) than other Ptychodus; (3) sharp cutting edge on ridge tops with long wave-like swaths between ridges; (4) low crown height; and (5) granular marginal texture.

Edited May 26, 2022 by LSCHNELLE
typos

[LSCHNELLE]

On 5/25/2022 at 5:52 PM, LSCHNELLE said:

Nice teeth!  I would think Ptychodus latissimus for both.  Notes:  (1) see most recent tooth posted here before yours; (2) typically fewer ridges (six each) than other Ptychodus; (3) sharp cutting edge on ridge tops with long wave-like swaths between ridges; (4) low crown height; and (5) granular marginal texture.

@rwiseAbove is my opinion  in case you want to know. Your question might be better reviewed in the Fossil ID section. Your first tooth is likely NOT P. decurrens because P. decurrens typically has low crown with about 8 to 12 parallel ridges that extend to the tooth margin and then bifurcate. Yours has only the low crown aspect of those four characteristics and the ridges terminate well before the marginal edge. It only has six ridges. 

[LSCHNELLE]

On 11/29/2016 at 1:14 PM, LSCHNELLE said:

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.  

Shawn Hamm gave his opinion on the dentition a few years ago. He first thought P. occidentalis based on the photo only.

[siteseer]

On 1/14/2021 at 8:38 AM, Seaspawn said:

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.

 

Ptychodus teeth are also found in Kansas, Oklahoma, Utah, Wyoming, Colorado, South Dakota, Montana, and Canada.

 

 

[truceburner]

On 9/20/2022 at 7:18 PM, siteseer said:

 

Ptychodus teeth are also found in Kansas, Oklahoma, Utah, Wyoming, Colorado, South Dakota, Montana, and Canada.

 

 

And Russia. https://instagram.com/irenochka62?igshid=YmMyMTA2M2Y=

[siteseer]

8 hours ago, truceburner said:

And Russia. https://instagram.com/irenochka62?igshid=YmMyMTA2M2Y=

 

And England, France, Kazakhstan, and Japan.

[mike23]

these are really cool.  Seeing the teeth from Denton Co, makes me hopeful I might find some in my hunting grounds.

[LSCHNELLE]

On 5/16/2022 at 5:19 AM, rocket said:

just for showing, a very nice Ptychodus decurrens from middle turonian of Dortmund, nw-Germany, coming from the collection of a friend of mine

@rocket

Based on Middle Turonian age and the rounding at the margin, I think that this is more likely a Ptychodus marginalis.

[rocket]

11 hours ago, LSCHNELLE said:

@rocket

Based on Middle Turonian age and the rounding at the margin, I think that this is more likely a Ptychodus marginalis.

 

oh, thanks, I will talk to my friend and check

[LSCHNELLE]

5 hours ago, rocket said:

 

oh, thanks, I will talk to my friend and check

@rocket

Ptychodus decurrens can be Middle Turonian at its youngest age. Maybe, the other side of your tooth has dendritic branching of ridges to the edge of the margin. If so, then it is properly diagnosed as Ptychodus decurrens. If the ridges are also rounded with a broader margin, then it more likely is Ptychodus marginalis. Again, without an associated set of teeth, this is only an educated guess based on tooth morphology.

Edited November 25, 2022 by LSCHNELLE

[rocket]

15 minutes ago, LSCHNELLE said:

@rocket

Ptychodus decurrens can be Middle Turonian at its youngest age. Maybe, the other side of your tooth has dendritic branching of ridges to the edge of the margin. If so, then it is properly diagnosed as Ptychodus decurrens. If the ridges are also rounded with a broader margin, then it more likely is Ptychodus marginalis. Again, without an associated set of teeth, this is only an educated guess based on tooth morphology.

 

thanks again. Always complicated with the Ptychodus... when we wrote a paper about the fauna (total fauna, fishes had been only less than 10%) from there many years ago we had several Ptychs we did not 100% know... Nice literature about english and a bit about german Ptychs, but not absolutely sufficient...

Edited November 25, 2022 by rocket

[LSCHNELLE]

On 7/25/2010 at 3:30 PM, Tony Eaton said:

I'm recycling some content from a prior post to cobble together a quick, non technical guide to ID Ptychodus teeth. Many of the pictures below are from CreekCrawler.

A few terms:

 

1. transverse ridges = the lines going across the tooth
2. crown = the abrasive "eating" surface of the tooth
3. margin = the area around the crown above the root

 

flat crowned, from oldest to youngest:

Ptychodus decurrens

 

• low crown with ridges that split (bifurcate) to the end of the marginal area

 

http://farm5.static.flickr.com/4076/4807278088_118329b99a.jpg

Ptychodus marginalis (polygyrus)

 

• crown only moderately raised
• ridges circle crown at marginal area and margin has a circular "finger print" pattern unlike decurrens

 

http://farm5.static.flickr.com/4081/4807277210_fed82602c1.jpg

Ptychodus latissimus

 

• few, thick, "sharp" ridges on the low crown
• little marginal area

 

http://farm5.static.flickr.com/4121/4806655695_1ec3a110f0_m.jpg

Ptychodus martini

 

• very low crown, unlike decurrens and marginalis
• the marginal area is rough or non existent and has no discernable pattern
• more ridges and generally more rectangular compared to litissimus

 

http://farm5.static.flickr.com/4098/4827562753_f387287fd7.jpg

high crowned, oldest to newest:

Ptychodus anonymus

 

• small in general
• 10+ ridges
• rough margin
• crown lower than whipplei and more rounded than mammillaris

 

http://farm5.static.flickr.com/4135/4827323677_c734855de1_b.jpg

Ptychodus occidentalis

 

• gently curved high crown at a slight angle to margin unlike mammillaris
• 10+ fine ridges
• ridges branch into the marginal area unlike anonymous

 

http://farm5.static.flickr.com/4035/4673307815_9b5e843d2a.jpg

Ptychodus mammillaris

 

• crown attached at a steep angle to the marginal area unlike occidentalis
• ridges are course and crown wider/squarer than anonymous
• marginal area has a circular pattern around the crown

 

http://farm5.static.flickr.com/4137/4806655949_af319493f6.jpg

Ptychodus whipplei

very high crowned, peg like

transverse ridges generally do not extend to the margin

Ptychodus mortoni

 

• the crown is pointed with ridges running together meeting at a single point at the top of the crown

 

http://farm5.static.flickr.com/4073/4828264368_9dc6bef454.jpg

Ptychodus atcoensis (sp.)

 

• front to back (labial to lengual) median line
• thick ridges that form a "chevron" pattern
• recenly named by Shawn Hamm, previously Ptychodus sp.

 

http://farm5.static.flickr.com/4076/4827431719_7fbe50bd14.jpg

Ptychodus rugosus

 

• most rare Ptychodus at least in Texas, no pictures to post ;-)
• transverse ridges are rough and poorly defined, almost giving the ridges a heavily "rusted" outline

 

Orginal post with some other great picks from kknight.

http://www.thefossilforum.com/index.php/topic/14366-ptychodus-occidentalis/

It's time for an addition to this post for
Ptychodus hunters who find a strange
looking miniature version of these
species from the Upper Medial
(UMF) or upper centerline (aka symphosial) tooth file.

 

These UMF teeth are a fraction of the medial file tooth size and they have similar marginal and ridge patterns to the characteristic medial file teeth.

 

They have an oversized root and a strangely proportioned crown. It's usually much narrower from side-to-side (labial/lingual) than in the
front-to-back (anterior/posterior) direction.

 

Otherwise, Ptychodus medial file teeth are usually rectangular to square with somewhat rounded corners and the largest dimension is primarily width-wise.

Here are five species in age order, four which I collected and the last one found by @JohnJ with @Jared Con a shared adventure.

 

Ptychodus anonymous (Middle Cenomanian to Middle Turonian)

Not the best image - pictured through my glass display.

 

 

Ptychodus occidentalis (Middle Cenomanian to Middle Turonian)

 

 

Ptychodus marginalis (Late Cenomanian to Late Turonian)

 

 

Ptychodus decurrens (Late Cenomanian into Turonian) - not yet verified by Shawn Hamm)

 

 

Ptychodus new species (Middle to Late Turonian) - not yet verified by Shawn Hamm because he has never seen an UMF example)

 

Please add any verified UMF teeth you might have that aren't listed here (such as P. whipplei, P. rugosus, P. polygyrus, or P. mortoni.

 

Edited March 15, 2023 by LSCHNELLE
Inserted images between text. Corrected the person who found the last UMF tooth.

[Jared C]

7 hours ago, LSCHNELLE said:

Here are five species in age order, four
which I collected and one collected by @Jared Con a shared adventure.

 

To be fair, it was actually @JohnJ that spotted that tooth during the excavation, though the tooth will join the collection ranks of fossils found affiliated with that excavation  

[LSCHNELLE]

3 hours ago, Jared C said:

To be fair, it was actually @JohnJ that spotted that tooth during the excavation, though the tooth will join the collection ranks of fossils found affiliated with that excavation  

Thanks @Jared C. I just corrected the post, but I kept you in the adventure.

[Mikrogeophagus]

I was told this UMF would be useful here . Suspected to be Ptychodus marginalis from the Middle Turonian Kamp Ranch of North Texas.

 

[Syndy]

On 7/26/2010 at 6:31 PM, Tony Eaton said:

Hieronymus, thanks for the feedback. I enjoy the debate :-)

I have just taken a picture that might be a better diagnostic example. Here is a picture of 2 teeth roughly the same size from the same site (middle Turonian, Kamp Ranch Fm., Denton Co.)

http://farm5.static.flickr.com/4112/4832923794_a3411304c6.jpg

The tooth on the left is mammilaris, the one on the right anonymous. They have more or the same margin design and same ridge count, but the difference is that mammilaris is much more squared off (flat) at the top of the crown.

I have several teeth that are less clear cut and seem to be variations between mammilaris, anonymous, and even a bit like mortoni or atcoensis.

The picture of anonymous in my post above includes a tooth, (second tooth on the bottom left) that I might consider mammilaris judging by just that picture. In the pictures I included originally of mammilaris, the tooth on the right has a flat crown, but it is more narrow compared to most "mammilaris" that I've collected and at the angle I picked it is not clear. Here is another view where the flat crown is more obvious.

http://farm5.static.flickr.com/4120/4807277936_b20c76427d_m.jpg

Unless I saw a naturally associated tooth set that showed morphology of both the flat and rounded crowns I would not agree that anonymous is a nomen dubium (doubtful name).

It looks like the roof of a mouth, feline.

[LSCHNELLE]

On 11/26/2016 at 4:49 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. 

Shawn Hamm told me a while back that this dentition looked like Ptychodus occidentalis. Based on the crown height and multiple finer ridges, I think that is a good possibility. But I am not entirely sure. Both Ptychodus decurrens and Ptychodus occidentalis would be very rare dentitions to find in  the Western Interior Seaway. UT students said it was donated without an understanding of where it came from.