Ptychodus mammilaris or Ptychodus latissimus?

[Mikeyz]

Hello everyone,

Yesterday my eyes spotted a Ptychodus tooth.

Cleaned it and i can't get a grip which species it is.

First i thought P. mammilaris and later i thought P.lattisimus.

But it's such a beauty that i bring her/she up in the forum.

Have a beautiful day everyone.

And for those who will go on a fossil trip. Mazal tov

 

Edited March 6, 2022 by Mikeyz

[Thomas.Dodson]

Looks like P. latissimus. I'm not seeing the concentric ridges I'd expect in P. mammilaris. The granular margin is rather large for P. mammilaris as well.

[siteseer]

10 hours ago, Thomas.Dodson said:

Looks like P. latissimus. I'm not seeing the concentric ridges I'd expect in P. mammilaris. The granular margin is rather large for P. mammilaris as well.

 

It has a profile more like P. polygyrus.

[Mikeyz]

Well i thought about it...but the top (crown) of the tooth is much higher then the P.polygyrus.

I'll ask Shawn Hamm maybe he can spread some light on the matter. Thanks anyway.

Ptychodus teeth are so interesting...will be continued 

[Thomas.Dodson]

2 hours ago, siteseer said:

 

It has a profile more like P. polygyrus.

It certainly does. From what I understand P. polygyrus can be distinguished by having more transverse ridges. References describe a concentric patterned marginal like P. mammilaris for P. polygyrus as well although this might not always be present. I wonder which characters are most reliable.

 

Do you have any stratigraphic information for where you found this tooth?

[LSCHNELLE]

I am with Thomas.Dodson on the need for stratigraphic information.  Heterogeneity within each Ptychodus species means that they can share common features with other species.  That being said, my first impression was a Ptychodus marginalis medial or symphosial file tooth (Late Cenomanian to Turonian age). But, there are only 7 or 8 ridges instead of the typical 10 to 14.  I don't see P. mammillaris even though the ridge count is about right.  P. mammillaris ridges terminate sharply at the margin and these curve back anteriorly.  It's not P. latissimus which has very sharp ridges with a wide curved valley between and an overall ridge pattern that reminds me of a puckered kiss shape. So, it is either P. marginalis or a P. polygyrus juvenile tooth.  P. polygyrus adults may have a similar number of ridges, but the ridges usually extend to the edge of the tooth with no marginal area and the teeth crowns are low crowned.  This is low to almost moderately crowned.  P. polygyrus symphosial files sometimes have a wide margin like this one.  But, if so, this would likely be a juvenile because of the "small" tooth size. 

Edited March 6, 2022 by LSCHNELLE

[Mikeyz]

Thank you for explanation...I'm blown away :-)

didn't think about the possibility of a juvenile tooth.

Stratigraphic information about the tooth is poor, but it's within 150 meters of the 65+ teeth i found last November.

Thanks again LSCHNELLE.

[LSCHNELLE]

Your welcome.  The Menuha Formation is Santonian-Early Campanian Age. So, it could not be a Ptychodus marginalis. GREAT FIND.  Certainly, a Ptychodus polygyrus like you found before.  Very rare. 

[Mikeyz]

Learning everyday from you guys on the forum.

Thank you.

Got lucky today again. 50 km at another location. 

It's got a little wear and tear but the nicest thing about the tooth is that another tooth was "rubbing" the other tooth...it could be a good sign that they shed there teeth. Not that often as other shark species.

Hope you can see the wear on the picture.

Also uploaded a picture of the 2 together

[siteseer]

The matrix looks like a chalk.  It would be older than the Maastrichtian phosphates that extend from Morocco across North Africa into the Middle East.  Israel has a range of fossil ages for such a small country.  I've read about Jurassic ammonites and there's a known Neanderthal site (Late Pleistocene) as well.