Niobrara Chalk Ptychodus teeth

[fossilsonwheels]

I’ve had these three Ptychodus teeth for awhile but hadn’t made any serious attempts at ID. I’m finally starting to work on the Ptychodus display though so it’s probably time to ID them. They are all Niobrara Chalk teeth. 2 from Smoky Hill, 1 Fort Hays Limestone. 
 

First up is the Fort Hayes tooth. Roughly 6mm wide so quite small and very flat crown. It does appear to have a circular pattern so I thought perhaps polygyrus/marginalis but I’m not at all confident in that as an ID. 

[fossilsonwheels]

Next tooth, Smoky Hill Chalk Trego County. Very small 4mm wide and very flat crown. My guess would be some sort of posterior tooth but no ID on species. 

[fossilsonwheels]

Last tooth. Smoky Hill Gove County. Largest tooth at 13mm wide, moderately raised crown. Maybe P. martini based on a few thick ridges but that’s an uneducated guess. 

[LSCHNELLE]

18 hours ago, fossilsonwheels said:

Last tooth. Smoky Hill Gove County. Largest tooth at 13mm wide, moderately raised crown. Maybe P. martini based on a few thick ridges but that’s an uneducated guess. 

These teeth are difficult to ID with the current pics - maybe due to small size. This last one has the best pics. It could be either P. latissimus or P. martini. P. latissimus is more likely based on the wider granular margin in this last picture. P. martini usually reaches closer to the marginal outer edge.

[fossilsonwheels]

6 hours ago, LSCHNELLE said:

These teeth are difficult to ID with the current pics - maybe due to small size. This last one has the best pics. It could be either P. latissimus or P. martini. P. latissimus is more likely based on the wider granular margin in this last picture. P. martini usually reaches closer to the marginal outer edge.

I appreciate the help and will try to take better pictures, particularly of the first one and second one. I think the third is latissimus after looking at one of Hamms papers. I think the second might too after looking at the paper. There was one that looked very similar. 

[LSCHNELLE]

On 4/29/2023 at 1:12 AM, fossilsonwheels said:

I’ve had these three Ptychodus teeth for awhile but hadn’t made any serious attempts at ID. I’m finally starting to work on the Ptychodus display though so it’s probably time to ID them. They are all Niobrara Chalk teeth. 2 from Smoky Hill, 1 Fort Hays Limestone. 
 

First up is the Fort Hayes tooth. Roughly 6mm wide so quite small and very flat crown. It does appear to have a circular pattern so I thought perhaps polygyrus/marginalis but I’m not at all confident in that as an ID. 

I think that you are correct with your ID of this tooth.  It is likely to be a Ptychodus marginalis posterior file tooth based on the concentric pattern on both margins. But, it would have been found in the lowermost Fort Hays Limestone (Upper Turonian) - not any higher. Does that sound right?