Horse Teeth

[worthy 55]

These teeth came out of the Santa Fe River near High Springs.

[Fruitbat]

Very nice horse teeth....three lowers and an upper. I love that phosphatic black coloration. We don't see that very often in the Dallas area.

-Joe

[Fruitbat]

As an addendum - these teeth are likely from a species of Equus because of the attached protocone. That is, of course, assuming that the teeth you found are of Pleistocene age. I do know that the Miocene Thomas Farm locality is on the Santa Fe River but where it is relative to High Springs I don't know. Which species of Equus is up for debate because isolated horse teeth are notoriously difficult to identify as to species.

The first one is a lower right cheek tooth (premolar or molar)

The second one is a lower left cheek tooth (premolar or molar)

The third one is a lower left M3 (third molar)

The fourth one is an upper left M3 (third molar)

Hope this helps a little,

-Joe

[Harry Pristis]

As an addendum - these teeth are likely from a species of Equus because of the attached protocone. That is, of course, assuming that the teeth you found are of Pleistocene age. I do know that the Miocene Thomas Farm locality is on the Santa Fe River but where it is relative to High Springs I don't know. Which species of Equus is up for debate because isolated horse teeth are notoriously difficult to identify as to species.

The first one is a lower right cheek tooth (premolar or molar)

The second one is a lower left cheek tooth (premolar or molar)

The third one is a lower left M3 (third molar)

The fourth one is an upper left M3 (third molar)

Hope this helps a little,

-Joe

These teeth look to be about the right size for Equus sp., Worthy. There are other species with brachyodont teeth and complex enamel plications; but, those species tend to have smaller teeth, sometimes much smaller. The larger horse teeth commonly found in the rivers here are Equus sp.

Thomas Farm has some horses, but none has unequivocally hypsodont teeth. The horses from Thomas Farm are Anchitherium, Archeohippus, and Parahippus -- all with brachyodont teeth. Thomas Farm is just too early for the horses to have fully evolved hypsoodonty. (This is great! I've never had the opportunity to add these words to my active vocabulary. They're mine now!)

Joe is right about the species of Equus. I don't think that problem has been of much interest for a long time now.

Single teeth of the smaller, earlier horses usually can be identified, but it is time-consuming until you have done it many times. I have never been that interested in horses. I have a small comparison collection of Florida horse teeth, but I seldom use it. Those are all teeth I took to the museum for identification.

---------Harry Pristis

[Fruitbat]

Actually, I think Harry mixed this one up just a bit.

Brachyodont teeth are low-crowned, typical of browsers, and the more 'primitive' condition among horses. Hypsodont teeth are high-crowned, typical of grazers (like 'modern' horses) and generally have the more complex enamel foldings. Equus (the 'modern' one-toed horse - Pleistocene/Recent), most genera of Pliocene and late Miocene horses and species of Parahippus (a three-toed horse with only the middle toe reaching the ground; found at Thomas Farm - Miocene) all have more-or-less hypsodont teeth and were likely grazers (eaters of abrasive grasses).

Archaeohippus, (Miocene) a three-toed browsing horse present at Thomas Farm and Anchitherium, (Miocene) a three-toed horse present at Thomas Farm, both have brachyodont teeth indicating they were probably browsers (eaters of soft vegetation like leaves).

Regardless of the details, your fossil horse teeth are most likely Equus based on size, hypsodonty, the attached protocone and the complexity of the enamel pattern.

-Joe

[Harry Pristis]

Actually, I think Harry mixed this one up just a bit.

Brachyodont teeth are low-crowned, typical of browsers, and the more 'primitive' condition among horses. Hypsodont teeth are high-crowned, typical of grazers (like 'modern' horses) and generally have the more complex enamel foldings. Equus (the 'modern' one-toed horse - Pleistocene/Recent), most genera of Pliocene and late Miocene horses and species of Parahippus (a three-toed horse with only the middle toe reaching the ground; found at Thomas Farm - Miocene) all have more-or-less hypsodont teeth and were likely grazers (eaters of abrasive grasses).

<snip>

-Joe

Harry surely did transpose those two words, "brachyodont" and "hypsodont." He has edited his post to correct the error. Thanks for the correction, Joe!

Joe and I agree on anchitheres and Archeohippus from Thomas Farm (Middle Hemingfordian, about 18 Ma.) -- they are browsing horses with brachyodont teeth.

We don't agree (depending on the definition of Joe's "more-or-less hypsodont") that Parahippus leonensis is a grazing horse with hypsodont teeth. It is not that simple.

Here's what Hulbert (Ed.) says in THE FOSSIL VERTEBRATES OF FLORIDA about P. leonensis :

Its morphology is relatively advanced for a

Parahippus

and is very close to that expected in the ancestor of all more hypsodont horses.

P. leonensis

was a mixed-feeder, lived to a maximum of nine years, and averaged about 160 pounds. . . .

Horses with more hypsodont teeth than

Parahippus

first appeared in North America about 17 Ma, although

Archeohippus

,

Parahippus

, and anchitheres lingered on.

Sooo . . . I think of P. leonensis as having brachyodont teeth with some (evolutionary) hints of hypsodonty to follow. I suppose you as easily could think of the same species as an advanced horse with primitive tooth characters, but that seems counterintuitive.

To make it clear what we're discussing, here is an image of Parahippus, an anchithere, and a hypsodont tooth from a Late Miocene (Hemphillian) three-toed horse, Nannippus minor.

[Fruitbat]

Ah...I love a good discussion about Perissodactyls!!! Sorry to hijack your post, worthy 55

From the Florida Museum of Natural History web page entry on Parahippus:

Some species of this remarkable German Shepherd-sized horse developed teeth that were tall, or "high-crowned." High-crowned teeth may have permitted this horse to have some grass in its diet. Because grass is an abrasive food that wears teeth down, short teeth in grass-eating animals would result in an early death from starvation.

Other advancements in the teeth include the development of cementum, a protective coating of the teeth, and the molar ridges characteristic of the modern horses.

At the Fossil-Treasures-of-Florida.com web site are some pictures that illustrate upper and lower cheek teeth from Parahippus leonensis that aren't from an individual quite as old as the ones that Harry Pristis posted (and thus, not as badly worn down). You can see the trend toward hypsodonty in these shots: Fossil-Treasures-of-Florida Web Page

In her Spring 2006 Paleobiology article titled Evolution of hypsodonty in equids: testing a hypothesis of adaptation., Caroline A.E. Strömberg labels some of the "Parahippus" (her quotes) as mesodont (middle toothed), implying that their teeth were intermediate between the brachyodont (low-crowned teeth) early equids and the more hypsodont (high-crowned teeth) later equids. From her paper:

The coincidence, at a currently coarse scale, of mesodont "Parahippus" taxa and grass-dominated habitats in the Central Great Plains sheds some light on this question. Although more data from the early late Arikareean are needed to verify the pattern, it implies that (small) changes in tooth crown height in this lineage started roughly at a time when grasses were becoming important parts of ecosystems.

From the National Park Service information for the John Day Fossil Beds in Oregon:

Species of Parahippus have teeth of medium height good for eating a variety of grasses and leaves. They have three toes, but the side toes are greatly reduced. These horses are thought to be a link between forest-dwelling horses and grassland dwelling razers.

Fossils of Parahippus are found in Oregon the Great Plains and Florida. Species in this genus lived from 24 -17 million years ago, during the Haystack Valley Assemblage.

So...in a nutshell...Harry Pristis and I both agree that Parahippus is an intermediate species but as far as the teeth go...he sees the glass as half empty (brachyodont) and I see the glass as half full (hypsodont).

-Joe

[Harry Pristis]

Ah...I love a good discussion about Perissodactyls!!! Sorry to hijack your post, worthy 55

From the Florida Museum of Natural History web page entry on Parahippus:

At the Fossil-Treasures-of-Florida.com web site are some pictures that illustrate upper and lower cheek teeth from Parahippus leonensis that aren't from an individual quite as old as the ones that Harry Pristis posted (and thus, not as badly worn down). You can see the trend toward hypsodonty in these shots: Fossil-Treasures-of-Florida Web Page

In her Spring 2006 Paleobiology article titled Evolution of hypsodonty in equids: testing a hypothesis of adaptation., Caroline A.E. Strömberg labels some of the "Parahippus" (her quotes) as mesodont (middle toothed), implying that their teeth were intermediate between the brachyodont (low-crowned teeth) early equids and the more hypsodont (high-crowned teeth) later equids. From her paper:

From the National Park Service information for the John Day Fossil Beds in Oregon:

So...in a nutshell...Harry Pristis and I both agree that Parahippus is an intermediate species but as far as the teeth go...he sees the glass as half empty (brachyodont) and I see the glass as half full (hypsodont).

-Joe

Well, Joe, this thread has veered off into near-obfuscation. You have a good imagination if you really believe that "You can see the trend toward hypsodonty" in a couple of unworn horse teeth. <chuckle>

I rest my case!

--------Harry Pristis

[Fruitbat]

Well...considering the truly brachyodont horses like Hyracotherium, Orohippus and Mesohippus, it isn't too great of a stretch of the imagination to see that the teeth of Parahippus show a trend toward hypsondonty. You may, however, rest your case! However, I hardly consider logical and well-supported scientific discourse to fall under the heading of obfuscation.

-Joe

[kauffy]

wow...this was very interesting to read, but i must say its getting a bit technical for me! HAHA

nice teeth worthy!

[Guest Cris]

This is a very interesting topic, indeed... I've learned what quite a few new words mean Seriously guys, this has been very educational... Thanks.

[Harry Pristis]

Here's a classic illustration, adapted from W. K. Gregory, 1951.

[worthy 55]

WOW!!!

That sure was interesting and educational. Now I know where that post went to. I was trying to place it on the map HaHa! oh well. I was wanting to know if the upper molar is from a Protohippine horse ?

[Fruitbat]

I'd be more likely to say Equus than Protohippus because, even though Protohippus does exhibit the attached protocone on the upper teeth, the protocone tends to be more oval or slightly elongated in outline than does the protocone in Equus. In addition, Protohippus protocones tend to have straight lingual borders and the tooth you pictured definitely doesn't.

The simple enamel folding on the fossettes is almost Protohippus-like but the characteristics of the protocone and a few other features make me think Equus. Any idea of the age of the stratum that this fossil came from? Protohippus tends to be late Miocene while Equus is pretty much a Pleistocene horse.

-Joe

[Harry Pristis]

I'd be more likely to say Equus than Protohippus because, even though Protohippus does exhibit the attached protocone on the upper teeth, the protocone tends to be more oval or slightly elongated in outline than does the protocone in Equus. In addition, Protohippus protocones tend to have straight lingual borders and the tooth you pictured definitely doesn't.

The simple enamel folding on the fossettes is almost Protohippus-like but the characteristics of the protocone and a few other features make me think Equus. Any idea of the age of the stratum that this fossil came from? Protohippus tends to be late Miocene while Equus is pretty much a Pleistocene horse.

-Joe

Worthy . . . Here is an Early Middle Miocene protohippine horse, Calippus, which displays the characteristics that Joe is describing.

[worthy 55]

Ok ,this is why I was asking about it being Protohippine. Thanks guys!!

Red

[amber.eyes]

Hi

I have been interested to see this thread of conversation as I have found what I think may also be a fossilised equine tooth of some kind and would love to have feedback from anyone that knows their stuff! It was found a beach in Lowestoft / Suffolk / UK. It is the UK's most easterly beach.

Thanks for sharing your photo's, They are amazing!

[siteseer]

That appears to be a seriously waterworn Equus tooth.

Hi

I have been interested to see this thread of conversation as I have found what I think may also be a fossilised equine tooth of some kind and would love to have feedback from anyone that knows their stuff! It was found a beach in Lowestoft / Suffolk / UK. It is the UK's most easterly beach.

Thanks for sharing your photo's, They are amazing!

[Youngcn]

great info

Edited February 11, 2020 by Youngcn
I posted it in the wrong place.