4/21: Chunky Ptychodus....atcoensis? N Tx

[John S.]

Biggest ptychodus I've found. Atcoensis?

[John S.]

Eagle Ford Group

86-92 mya

[John S.]

Or Polygyrus?

[fossilized6s]

Sorry i can't help with an ID, but that is a nice piece! Congrats on the find.

[old bones]

That's a whopper! I love finding Ptychodus teeth. Sorry, but I'm not able to help with the ID, just wanted to say what a great big find.

[John S.]

Thanks guys it was a nice surprise. Thought it was a chunk of bone at first.

[sharko69]

That is a crazy nice lunker. You hitting it hard after all the rain?

[John S.]

Just a bit for now. Trying to be patient, wait for the storms to roll in this week. I got rained on today but it was worth it : )

[siteseer]

That is one oddball pattern. Going by the Welton and Farish (1993) book, it looks like a cross between atcoensis and latissimus and it's a big one for either. I would lean to atcoensis.

Biggest ptychodus I've found. Atcoensis?

[sixgill pete]

WOW!! What a beautiful tooth. Definitely a keeper. Like most of the others have said, I have no idea of the ID, but I want one!!!!!

[John S.]

Thanks a lot. I will call it atcoensis for now.

[LSCHNELLE]

Based on Hamm's 2008 Masters thesis:

http://www.academia.edu/6137340/Early_Coniacian_Late_Cretaceous_Selachian_Fauna_from_the_Basal_Atco_Formation_Lower_Austin_Group_North_Central_Texas), as a non-expert, I would question P. Atcoensis. It's crown is usually very high - yours is not. Look at Plate 6B Item G under P. Anonymous. It would be unusually large.

[TNCollector]

No help on ID, but I really wish we had some of those over here. They are really cool, that is a huge one!

[Ridgehiker]

Wow. Super specimen

That's the biggest i've seen. We have some deposits with Ptychodus teeth ( unstudied) but the ones I find are just 'babies'. We find ours on the surface in greyish deposits. Rarely anything found with them but the occasional other species of shark tooth.

Ptychodus teeth are one of my favourite finds. There's something satisfying in their shape and detail.

[ynot]

Neat find!

Congratulations!

Tony

[siteseer]

I see what you're saying. I'm going to have to disagree with myself.

First of all, it's a large tooth. Any Ptychodus over an inch high or wide could be considered large. The ridge pattern is highly irregular, not fitting the description of any species. In side view without consideration of the ridges, it follows the form of P. occidentals (according to the pinned thread) which is found at that size and I believe it would be the right age but I think an update of Welton and Farish might call it P. marginalis, which also reaches that size, since P. occidentals has more of a dome-like crown. It would interesting to hear Hamm's opinion.

Thanks for that link too.

Jess

Edit: I forgot to mention the reference I was basing the ID on. I think Hamm might consider it P. marginalis with irregular ridges.

Based on Hamm's 2008 Masters thesis:
http://www.academia.edu/6137340/Early_Coniacian_Late_Cretaceous_Selachian_Fauna_from_the_Basal_Atco_Formation_Lower_Austin_Group_North_Central_Texas), as a non-expert, I would question P. Atcoensis. It's crown is usually very high - yours is not. Look at Plate 6B Item G under P. Anonymous. It would be unusually large.

Edited May 29, 2016 by siteseer

[truceburner]

Ptychodus teeth are among my favorite finds as well. Rare enough to be special every time. Nothing to offer as to the identification of this lovely specimen.