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A Small Horse Molar


Shellseeker

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I am always confused by the size of horse teeth. I find some massive Equus in the range of 4plus inches long and 1.25 inches square. Then a much smaller tooth that may look like Equus but has a significant size differentiation. Then there are very small molars that can only be pre-Equus ancestors.

We were hunting an area that has all 3 versions. Here is a Medium example (55 mm long, 16x 11 mm wide. It also has the nice characteristics of being unbroken and unerupted. My hunting buddy found a horse molar that was 40mm x 11mm x 5mm which definitely would be pre-Equus.

post-2220-0-11222300-1425830753_thumb.jpgpost-2220-0-19231800-1425830779_thumb.jpgpost-2220-0-39485100-1425830819_thumb.jpg

The last 2 photos seems to show an isolated protocone.

Question: Could this molar come from Equus sp.?

2) Is there documentation/book that provides size-range of molars as a step to identification? It is difficult to "read" the occlusal surface.

Thanks for any and all suggestions and comments. SS

The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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Could the smaller ones be from juvenile horses?

Good question. I have asked it also.

There can be significant difference in size between members of the same horse species. So it might be juvenile, might be female, etc That is what causes the confusion --

Take a look at this thread about a horse tooth I found last May -- It is Calippus Elachistus which lived between 8.7 and 11.5 mya. It has these small or medium sized teeth also. Generally, one can figure this out by examination of the chewing surface.

http://www.thefossilforum.com/index.php?/topic/46940-three-toed/?hl=calippus#entry506871

In this case , the chewing surface has not yet completely emerged. So I am trying to get some inferences by size of the tooth and the possible "isolated protocone" which would again identify this as not-equus.

The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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Hey Jack, nice one. I was intrigued and was looking at your find earlier and was wondering what Harry and the others would say...

I was trapped indoors with a bad back today and trying to humor myself and pretending I knew something with Hulberts book in hand so I was played with enhancing the photo looking for more details...

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I can see a few more details but....

Dang horse teeth!

Regards, Chris

Edited by Plantguy
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Harry, Thanks for the precise answer. Chris, thanks for the enhanced photo. You will have to tell me how you did that.. I had a very difficult time getting a focus on the protocone. I will contact Richard Hulbert and see whether there is sufficient detail to make a specific identification. I will update this with whatever I learn. Jack

The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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Harry, Thanks for the precise answer. Chris, thanks for the enhanced photo. You will have to tell me how you did that.. I had a very difficult time getting a focus on the protocone. I will contact Richard Hulbert and see whether there is sufficient detail to make a specific identification. I will update this with whatever I learn. Jack

Hey Jack, I use freebie software called Irfanview--I think I downloaded it from Cnet. I'm sure there are a slew of others that will do the same. Here are some screen shots of how to do it...not the exact pictures of me doing it the 1st time but you'll get the jist of it. I cropped it, converted to grayscale and then it has a color correction tool showing the image along side of its edited version where I lightened it and you can adjust contract, gamma correction and saturation using some sliding bars adjustments. The tool lastly has a separate sharpen function from that same image drop down menu which when applied a couple times it enhances/sharpens things..I usually save the file as I'm working on it just in case I screw it up along the way and dont want to start completely over but its pretty really quick once you get used to it. I'm sure there are some photo guys that could shortcut this and can make it quicker and probably offer a better tool......

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Goodluck with the ID!

Regards, Chris

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Chris, Thanks for posting the details -- I will follow in your footsteps.

Nate, You and Richard agree on both points. Just got his reply.

It is an upper molar of a 3-toed horse. It is not a deciduous tooth, but one of the permanent molar teeth. It had just started to erupt and wear when the animal died. A deciduous tooth at this stage of early wear would have a height of about 1/4 to 1/3 of this molar.

Because the occlusal surface is not fully formed at this stage, it is not possible to positively identify the specimen to a genus and species from these images. One could do some measurements of the height, length and width and from these narrow the field down to just a few contenders. Assuming the hand in the images is of average size, the tooth appears to be from one of the smaller equids, such as Nannippus or Pseudhipparion. In the old days we would actually cut the specimen with a rock saw to view the occlusal surface and get a firm identification. These days, assuming one has the funds and access to the right equipment, this can be done “digitally” by CT scanning and not damage the specimen.

Richard Hulbert 3/9/2015

This tooth is 55 mm long, -- A deciduous tooth might be 14-18 mm long, meaning that I could conceivably find a complete horse tooth that size!! I have learned something new. I do not believe that I will be cutting this specimen with a saw. :shake head: It is the BEST one I have by far.

The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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Harry, Nate, other horse experts:

Since it is still the last great fossil I have found, I have been investigating.. In this case using a couple of other finds from the same location. These do not seem to be Neohipparion Eurystyles because of obvious differences, but there are very similar to each other, but not exact...

Are these 2 molars from the same genus and species or not? Can the same genus/species have this much variation (such as the channel to the protocone on one but not the other)?

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The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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Hey Jack, some more nice finds!

Its late and I have no business posting anything other than I'm interested to see what the others have to say...if I squint and cross my eyes slightly I go with one of the Cormohipparions. Wait for someone who really knows what they are talking about!

Regards, Chris

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Interesting...the tooth on the right has a distinctly-attached protocone while the one on the left has an isolated protocone. I wouldn't think that the two are from the same species (or even the same genus, for that matter), though I'll hedge my bet by saying that the complexity of the features of horse enamel on the occlusal surface can vary dramatically with the level of wear.

-Joe

Illigitimati non carborundum

Fruitbat's PDF Library

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Joe,

First Thanks for the pointer to the McFadden 1984 paper. I have done an overall scan but it will take me a while to read and comprehend. It helps greatly with diagnostic differences between say Cormohipparion and Nannippus. It also reinforces your insight on the fact that the same tooth looks different depending on the amount of wear.

I tracked down the right molar to Cormohipparion Ingenuum http://www.thefossilforum.com/index.php?/gallery/image/36984-cormohipparion-ingenuum-upper-molar/

The one on the left seems to be Nannippus but there are so many candidates, I can not yet get more specific. The unique feature that I look for is that "larger loop at the bottom of the slightly left of center squiggly" :) Note how good I am with those scientific terms like loop and squiggly.

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This is a lot of fun. Almost like fingerprint matching w/o a national ACES system.

Edited by Shellseeker

The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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  • 2 years later...
On 3/13/2015 at 12:23 AM, Fruitbat said:

Interesting...the tooth on the right has a distinctly-attached protocone while the one on the left has an isolated protocone. I wouldn't think that the two are from the same species (or even the same genus, for that matter), though I'll hedge my bet by saying that the complexity of the features of horse enamel on the occlusal surface can vary dramatically with the level of wear.

-Joe

...according to the FLMNH website (see link), the one with the aforementioned isolated protocone is likely a hipparion species, while the one that is attached is a neohipparion species...

 

https://www.floridamuseum.ufl.edu/fhc/neoh.htm

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  • 1 year later...
On 2/25/2018 at 7:02 PM, whowat13 said:

...according to the FLMNH website (see link), the one with the aforementioned isolated protocone is likely a hipparion species, while the one that is attached is a neohipparion species...

 

https://www.floridamuseum.ufl.edu/fhc/neoh.htm

 

An old post where I requested an ID.. I noted that while I have identifications in my Gallery, never identified here in this post. Not identifying size was a dis_service on my part.  The Nannippus on the left is significantly smaller (relatively speaking) than the Cormohipparion on the right. They were found on the same hunting trip, and fortunately co_existed in the day...

2015Mar9thNpeninsulatusText.thumb.jpg.e2c045b05f4ea1f5c31bed541c12687b.jpg2015March9thCormohipparionIngenuumText.thumb.jpg.637ed65b343bdfc401e77f30642e655d.jpg

The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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