3 Toed Horse Tooth--Nannipus?

[Brandy Cole]

Weather was cold and windy yesterday, but sunny and calmer down in southeast Texas.  Sandy gravel matrix.

 

I always hate to get my hopes up too early in the game, but I think I may have found my first 3 toed horse tooth.

 

I looked at Hulbert's Fossil Vertebrates of Florida book. Photograph D on pg. 292 is a right m1 or m2 from nannippus aztecus. It appears pretty similar, but I'm not sure about size. Nannippus Aztecus would have been in Texas from late Miocene to Pliocene, so region would fit. And I think @garyc has found a nannippus on the Brazos before in this general region.

 

My husband and I weren't able to take very good pictures of measurements of the occlusal surface without sacrificing accuracy.  Gave up on trying to photograph it with the ruler and got better results.

 

MSCH, from root to parastyle: 36mm

APL, length of crown enamel: 18 mm

TRW, width of crown from mesostyle to posterior protocone: 16mm.

 

@Shellseeker @Harry Pristis @garyc

[fossilus]

Definitely 3 toed with the isolated protocone. It will be interesting what @Shellseeker has to say.

[Harry Pristis]

2 hours ago, Brandy Cole said:

My husband and I weren't able to take very good pictures of measurements of the occlusal surface without sacrificing accuracy.  Gave up on trying to photograph it with the ruler and got better results.

 

MSCH, from root to parastyle: 36mm

APL, length of crown enamel: 18 mm

TRW, width of crown from mesostyle to posterior protocone: 16mm.

 

Good job, Brandy!  Good images, good measurements, good research.  

[Lorne Ledger]

very nice 3-toed horse tooth!!!!!  

[garyc]

Nice tooth!

[Shellseeker]

Brandy, 

Gorgeous Tooth,  Great find.  I am jealous

and that's true even though I have more than my fair share of these... Almost all of those I have acquired in Florida (except for a few great examples that @siteseer has tempted me beyond endurance).

If you look up Nannippus on Wikipedia, you find that Florida has 5-6 types and Texas has 5-6 types.  We overlap on N. pennisulatus and N. aztecus. Based on other fauna, I find my peninsulatus at a Blancan mostly Pliocene site and my aztecus at a Miocene site.

Based on experience,  aztecus is smaller than peninsulatus.  I can not tell if there are variations in your tooth that would differentiate from other Texas Nannippus species,  but to me yours is peninsulatus. On this one below , I am 11 x 15 x 49 compared to your 18 x 16 x 36 mm.  A little different but close.

Here are my aztecus from the phosphate mines

 

Finally one smaller than aztectus.  likely morgani or simpsoni

 

Differentiating between Texas Nannippus species  is above my pay grade

[siteseer]

I'll have to let @fossillarry know about this one.

[Brandy Cole]

Thank you everyone.  When I was a kid, I remember one of my first horse books describing the origins of horses and showing pictures of three-toed horses.  It always fascinated me. So this find was particularly exciting for me.

 

I've never messaged Dr. Hulbert before, but I decided to ask him, and he was gracious enough to write back.

 

The short answer is that he believes it's a presently unnamed nannippus species that he's identified in the past instead of aztecus.

 

I could try to summarize his reply, but since I had to look up a couple of the words, it's probably better to just quote it. 

 

"Nannippus aztecus upper molars almost never have multiple pli caballins or a deep hypoconal groove. It is also larger than typical N. aztecus molars. Instead I think it belongs to an unnamed species of Nannippus from the Clarendonian Land Mammal Age that has been found in the Lapara Creek Fauna of coastal Texas as well as sites in Florida, Nebraska, South Dakota, Oklahoma, and the Texas Panhandle. I first recognized this new species way back when I was working on my dissertation, but have never gotten around to formally naming it. "

 

That would make it much older than I first thought.  Probably one of my favorite finds so far.  

[Family Fun]

Great find and as usual, I’m always learning something new with each thread I read.  If they are still looking to name it, seems Brandy Cole would be appropriate.  
 

Dr. Hulbert and his team are amazing.  They’ve never failed to respond to an email  of mine, and almost always within hours.  With everything on their plate, the effort they put forth helping the public is incredible.
 

Rick

[Shellseeker]

15 hours ago, Brandy Cole said:

Thank you everyone.  When I was a kid, I remember one of my first horse books describing the origins of horses and showing pictures of three-toed horses.  It always fascinated me. So this find was particularly exciting for me.

 

I've never messaged Dr. Hulbert before, but I decided to ask him, and he was gracious enough to write back.

 

The short answer is that he believes it's a presently unnamed nannippus species that he's identified in the past instead of aztecus.

 

I could try to summarize his reply, but since I had to look up a couple of the words, it's probably better to just quote it. 

 

"Nannippus aztecus upper molars almost never have multiple pli caballins or a deep hypoconal groove. It is also larger than typical N. aztecus molars. Instead I think it belongs to an unnamed species of Nannippus from the Clarendonian Land Mammal Age that has been found in the Lapara Creek Fauna of coastal Texas as well as sites in Florida, Nebraska, South Dakota, Oklahoma, and the Texas Panhandle. I first recognized this new species way back when I was working on my dissertation, but have never gotten around to formally naming it. "

 

That would make it much older than I first thought.  Probably one of my favorite finds so far.  

Brandy,

Can you just imagine the depth of knowledge that Richard has about small horses that allows him to write such a short paragraph with such conviction?  I was just stunned the 1st couple of times he evaluated small horse teeth that I had found, differentiating species by seemingly minor variations.  He and others like him who support our community so well, are a treasured resource. 

 

[fossillarry]

I believe your tooth is is more likely referred to Cormohipparion then Namnippus.The drawing of the tooth is from Hulberts' publication on Cormohipparion and Hipparion and was identified as Cormohipparion sphenodus but is now called C. quinni.  This tooth is 19.8 by 18.4 and is at least 31mm be in crown height,very close to the tooth in question . It is close to other C quinni pictures I have seen as well. The Brazos river is well known for producing Middle Barstovian age fossils,the age of C.quinni.  Clarendonian age deposits are not  known ,as far as I am aware, from the Brazos river which might produce specimens of C. ingenuum or N. new species of Hilbert,( see Florida Fossils edited by Dr. Hulbert for illustrations of these species) the only other likely horses this tooth could be from. As Dr. Hulbert has said ,it is difficult to identify single horse teeth, but when you find one you have to do your best to give it name.

[darrow]

Nice find!

 

I found this three toed horse tooth miles south of I-10.  I suspect these are transported from older formations significantly north of your area.

 

Hipparionini Molar? - Fossil ID - The Fossil Forum

[Brandy Cole]

@darrow Thanks!  If I remember right from reading old Brazos River archeological references, there should be some Miocene exposures (Fleming formation?) that have been documented north of me in Washington and Waller Counties.  

[Brandy Cole]

@fossillarry Thank you for taking a look.  I've seen several members mention your tremendous expertise when it comes to these types of teeth.

Here is a link to the document referencing Lapara Creek fauna contained a photo of the tooth that Dr. Hulbert believed it to be.

https://palaeo-electronica.org/content/2019/523-929/2474-lapara-creek-figures#f93

 

 

From what I've read about my area, expeditions a short way north of my location have uncovered specimens associated with Lapara Creek fauna before.  I assumed it washed down from there.