gorgeous ptychodus, but unsure of species

[Jared C]

Found this beauty recently in a middle turonian exposure of the Eagle Ford formation in Texas. Knowing the age, (91 million years) I'm able to rule out quite a few options, but I'm still stuck between P. anonymous, P. mammilaris, and the Ptychodus that Shawn Hamm will describe this year, which has also been found at this location. I don't think it's decurrens or marginalis, but I'm not great at Ptychodus ID yet so perhaps they're still options.

 

It's much larger than the P. anonymous teeth I've found, and being (perhaps) a posterior or lateral file tooth, I'm unsure of how to ID mammilaris there. I know @LSCHNELLE knows the diagnostic features of Hamm's upcoming Ptychodus, thoughts?

 

Scale bar= 1 cm

[Mark Kmiecik]

42 minutes ago, Jared C said:

 

 

I am ! Ptychodus. 

[Fossildude19]

1 hour ago, Mark Kmiecik said:

 

I am ! Ptychodus. 

 

Or 1 cm.  Ptychodus

 

Depending on your translation skills. 

 

 

@Jared C - Have you looked through this topic?

 

 

[Jared C]

24 minutes ago, Fossildude19 said:

Have you looked through this topic?

I have -  this ID remains a little pesky for me still, despite the great guide provided there

[LSCHNELLE]

Jared C - very nice find. This is a hard one.  It looks a little pathologic with the "scar" on the lingual side.  It doesn't fit tightly into any typical species characteristics. I had one from Upper Turonian that I thought was a pathological P. whipplei with a moderate crown height.  Shawn said that it was too hard to pin down. Yours has a granular marginal area.  It doesn't look enough like the pending new species and it also looks a little too large for that one. My guess is that it is a lateral file P. mammillaris because the ridges terminate abruptly at the marginal area with minimal turning. But, it is not classic P. mammillaris because the crown top is not flattened and the crown surface area is fairly limited.  I think those latter two features can occur more in lateral files. 

[LSCHNELLE]

It could also be a P. marginalis lateral file. They don't always have the 180 degree turning inwards of the ridges at the marginal area.  But, the crown area is a little smaller than I would expect. Both species are possible in the middle Turonian. Sorry, to blur the diagnosis. 

[Jared C]

1 hour ago, LSCHNELLE said:

Sorry, to blur the diagnosis

no need to apologize for anything! Once again a very thorough answer. Ptychodus ID doesn't seem to be very often straight forward. It's a tooth from the upper south bosque of central texas, so maybe your familiarity with that formation in the area will help favor one over the other. I haven't seen marginalis around these parts before, so I assume marginalis is rather uncommon around here?

[LSCHNELLE]

I have found 10 Ptychodus species in Central Texas counting the new one.  I still haven't found P. martini like others have.  For my 1200+ Ptychodus teeth, the most common is P. anonymous (60 - 65%). Then, P. mortoni 16%, P. occidentalis (9%), P. marginalis (4%), P. decurrens (2%), and the last four around 1% each. It all depends on what strata you hunt in.  My experience is:  Middle to Upper Cenomanian = P. anonymous and P. occidentalis (uncommon). Upper Cenomanian = P. decurrens (uncommon) and P. marginalis (rare). Lower Turonian = P. anonymous, P. marginalis (uncommon), and maybe P. decurrens. Middle Turonian = P. marginalis (uncommon), new species (common to uncommon), and maybe P. anonymous (rare) and (big maybe) P. whipplei.  Upper Turonian/Lower Coniacian = P. mortoni (common), P. latissimus (rare), P. atcoensis (uncommon), P. whipplei (rare), P. mammillaris (rare), and maybe P. martini (very rare). Younger Coniacian and Santonian = P. martini (rare), P. mortoni, and (dreaming) maybe P. rugosus (unknown).  P. polygyrus is very rare in Santonian-Campanian worldwide - but not yet found in Texas - only in Alabama. 

[Jared C]

1 hour ago, LSCHNELLE said:

I have found 10 Ptychodus species in Central Texas counting the new one.  I still haven't found P. martini like others have.  For my 1200+ Ptychodus teeth, the most common is P. anonymous (60 - 65%). Then, P. mortoni 16%, P. occidentalis (9%), P. marginalis (4%), P. decurrens (2%), and the last four around 1% each. It all depends on what strata you hunt in.  My experience is:  Middle to Upper Cenomanian = P. anonymous and P. occidentalis (uncommon). Upper Cenomanian = P. decurrens (uncommon) and P. marginalis (rare). Lower Turonian = P. anonymous, P. marginalis (uncommon), and maybe P. decurrens. Middle Turonian = P. marginalis (uncommon), new species (common to uncommon), and maybe P. anonymous (rare) and (big maybe) P. whipplei.  Upper Turonian/Lower Coniacian = P. mortoni (common), P. latissimus (rare), P. atcoensis (uncommon), P. whipplei (rare), P. mammillaris (rare), and maybe P. martini (very rare). Younger Coniacian and Santonian = P. martini (rare), P. mortoni, and (dreaming) maybe P. rugosus (unknown).  P. polygyrus is very rare in Santonian-Campanian worldwide - but not yet found in Texas - only in Alabama. 

very informative, I'm glad to know of someone with such expertise, especially locally. I was surprised that P. anonymous is a rare find for you in middle Turonian - I may have to go back and recategorize some of the middle Turonian teeth I hastily assumed belonged to P. anonymous. 

Crossing my fingers for your rugosus and a martini! I know an area in Travis county where there have been a few P. martini teeth found, including the (one) that I managed to find.  The next time we get a big rain, I'll gladly take you down if you want.

[LSCHNELLE]

I have found P. anonymous in middle Turonian. They just become less common in the places I have hunted. The new species is more common for me there. Here is a picture of one ID'd by Shawn from there (in middle) with nice Cretoxyrhina.