3-toed horse tooth ID - Peace River, Florida

[Meganeura]

Found a 3-toed horse tooth yesterday that I wanted to get ID’d! It has an APL of 16.2mm, a TRW of 15.2mm, and a height of 26.3mm.

 

@fossillarry @Shellseeker

 

[Shellseeker]

Well Daniel,

You likely will have to wait on Larry,  but in the meantime you might look for a similar tooth in this thread from 5 years ago......

 

I thought that this tooth was Cormohipparion,  but Richard corrected to Nannippus.

[Meganeura]

Just now, Shellseeker said:

Well Daniel,

You likely will have to wait on Larry,  but in the meantime you might look for a similar tooth in this thread from 5 years ago......

 

I thought that this tooth was Cormohipparion,  but Richard corrected to Nannippus.

Yeah - I compared it to my Cormohipparion ingenuum upper, and C. plicatile from Richard's book - but it's too big for C. ingenuum, and plicatile doesn't quite seem to match patternwise. Definitely need to wait for Larry though. 

I was also under the impression that based on this chart, N. aztecus is too small for your or my upper to fit - what's the Basal Crown length exactly? I've been thinking it was the APL.

[Shellseeker]

Here is Richard's response...

Quote

You got some right and some wrong.  The tooth in image C_PlicatileTxt1 is a left P2 of Nannippus aztecus.

C_PlicatileTxt2 is a left P3 or P4 of Nannippus aztecus.

Cormohipparion emsliei  is identified correctly and is an upper right M1 or M2.

NannippusP_lowerleft_m3 is a left lower m3, but is Nannippus aztecus and not N. peninsulatus.

Nannippus Ptxt1 and NannippusPtxt2 are both left upper M1 or M2 of Nannippus aztecus.

 

The Blancan species Nannippus peninsulatus is not present in the phosphate mines; the most common species is Nannippus aztecus.  It is from the late Hemphillian age.  There are also older species of Nannippus present.

Cormohipparion emsliei is the late Hemphiallian species of this genus, and so is common in the mines. Cormo. plicatile is an older species (late Clarendonian-early Hemphillian) that is rare in the mines.

 

Other common species are Pseudhipparion simpsoni and Neohipparion eurystyle.  More rare is Dinohippus mexicanus, which will look sort of like an Equus but more curved in the uppers and with a shorter protocone.

Extremely rare is Astrohippus stockii.

 

Richard

Now that you've asked on BSL, I am unsure.... but I have been moving my concept of upper N aztecus teeth toward 16 mm...

[Meganeura]

1 minute ago, Shellseeker said:

Here is Richard's response...

Now that you've asked on BSL, I am unsure.... but I have been moving my concept of upper N aztecus teeth toward 16 mm...

Interesting! Obviously Richard knows what he's talking about - perhaps I'm getting BCL and APL confused, then, and BCL is something entirely different. Or the chart is just outdated. 

@fossillarry once you get the chance - would you be able to chime on this? What the Basal Crown Length actually is, and whether you know if N. aztecus has a wider range than the chart details?

[Shellseeker]

9 hours ago, Meganeura said:

N. aztecus has a wider range than the chart details?

In Sept 2017,  a very good friend allowed me to purchase this set, that he had found while working in the phosphate mines...  I subsequently got identifications from Richard.

It was about this time that I came to the conclusion that N. aztecus has a range of occlusal lengths based of tooth position. 

[Meganeura]

22 minutes ago, Shellseeker said:

In Sept 2017,  a very good friend allowed me to purchase this set, that he had found while working in the phosphate mines...  I subsequently got identifications from Richard.

It was about this time that I came to the conclusion that N. aztecus has a range of occlusal lengths based of tooth position. 

Yeah that's certainly quite the range! Well I'll tentatively say N. aztecus for now then, I suppose!

[Terminal Stareasaurus]

I live in Wauchula Florida about a mile from the Peace River. It has been unnavigable since Ian in September. I am so wanting to get in it and dig. Kudos to you Meganeura for braving that water.

[Meganeura]

7 hours ago, Donna Straw said:

I live in Wauchula Florida about a mile from the Peace River. It has been unnavigable since Ian in September. I am so wanting to get in it and dig. Kudos to you Meganeura for braving that water.

Well I actually have been hunting some creeks nearby - haven’t touched the peace quite yet. That’ll be once it drops another foot or so. 

[fossillarry]

It is probably a right upper premolar 3/4 of Cormohipprion ingenuus based on small size and relatiively low plication count. Although it is very worn and thus in late wear stage the plications are deep and more numerous then in worn  teeth of Nannippus or Pseudhippariion.  I have equally worn teeth of C. emsliei that are much more plicated ,especially on the anterior halff of the prefossette, and so Cormohipparion ingenuus.

[Meganeura]

3 minutes ago, fossillarry said:

It is probably a right upper premolar 3/4 of Cormohipprion ingenuus based on small size and relatiively low plication count. Although it is very worn and thus in late wear stage the plications are deep and more numerous then in worn  teeth of Nannippus or Pseudhippariion.  I have equally worn teeth of C. emsliei that are much more plicated ,especially on the anterior halff of the prefossette, and so Cormohipparion ingenuus.

Thanks Larry! What exactly is the plication count? Is that the enamel folds? 

Also why is this one so much bigger than the other C. ingenuus upper molar I have? Or well, wider, I suppose - it's only 2.5mm taller, but 4mm wider. 

[fossillarry]

Yes, plication count = the number of enamel foldings on a the pre and post fossettes of upper molars.  !6mm apl by 15mm width by 26mm tall is not that large.for C. Ingenuus.  According to Dr. Hulberts' publication about Cormohipparion ingenuus  his measurements of upper teeth fall in about this size range, especially foe worn specimens. If  you can, take a couple of pictures of what you are calling C. ingenuus and post them to this thread. I can't think of what species you  have if they are a lot smaller then this tooth

[Meganeura]

8 hours ago, fossillarry said:

Yes, plication count = the number of enamel foldings on a the pre and post fossettes of upper molars.  !6mm apl by 15mm width by 26mm tall is not that large.for C. Ingenuus.  According to Dr. Hulberts' publication about Cormohipparion ingenuus  his measurements of upper teeth fall in about this size range, especially foe worn specimens. If  you can, take a couple of pictures of what you are calling C. ingenuus and post them to this thread. I can't think of what species you  have if they are a lot smaller then this tooth

Here’s my other one! You also ID’d it as an upper molar from C. Ingenuum. 

 

[fossillarry]

I believe the first tooth was a premolar which are usually larger then your second tooth, a molar.

[Meganeura]

7 minutes ago, fossillarry said:

I believe the first tooth was a premolar which are usually larger then your second tooth, a molar.

Thank you Larry! Much appreciated!