Horse Teeth: Question Regarding Fossilization

[Miatria]

I have a very general question regarding the amount of time it takes for an equus tooth to fully fossilize. I found some perfect, fossilized horse teeth in the Alafia River in an area where there was almost no other fossil material, save VERY well-worn fragments of dugong and turtle. It was suggested to me that the teeth could be from colonial era horses. I have read that in mineral-rich water, fossilization can occur rapidly, even in less than 100 years but do Florida rivers have that kind of mineral content or did I read some bogus material? I would appreciate any input.

[Harry Pristis]

You raise a number of questions. It's true, Florida spring waters are saturated with SiO₂ which permineralizes bone when it is exposed. This is a secondary preservation step. That is, in the case of Santa Fe River fossils, these are Pliocene - Pleistocene bones which have first been preserved with an uncertain degree of permineralization in clay sinkhole fill. . . . Uncertain because there is not much groundwater circulation in the clay. How long after exposure to the river water did the Santa Fe bones become stony? . . . I don't know, and there may be no definitive answer.

I don't know the Alafia, but I assume that it is a spring-fed river like the Santa Fe. But, you may have to look at other clues to the age of your teeth. What color is the enamel of your horse teeth? How many teeth did you find? Does any cementum remain on the teeth? Why don't you post some images of these teeth.

[Miatria]

Thanks for replying! The teeth look similar to equus teeth I've found in the Peace but the dearth of other fossil material where I was hunting in the Alafia led me to wonder...

[Harry Pristis]

Good images. If that cementum is crumbly, it may indicate that the teeth are recent. Other than that, the images don't say anything to me. Maybe a horse expert will step forward to identify the teeth as from a Paso Fino or Appaloosa, but that's beyond my competence.

[Cam28]

As much as I want to say they're from the Pleistocene, I don't know for sure. I have however found a partial raccoon skull from the peace which appears to be fossilized, but appears to be in too great of shape in a high energy environment to be that old http://www.thefossilforum.com/index.php?/topic/44019-peace-river-skull/. Also have had the same case with small delicate fish vertebrae (shown below). Believe I've read somewhere it can take only a few decades for something to mineralize.

Edited April 28, 2015 by Cam28

[erose]

Just to be sure…you guys aren't confusing dark staining for fossilization are you? But this brings up the question of collecting from river gravels. They are almost always out of context in the general sense that they have been moved from their original point of burial. They are float. Just like a trilobite in the talus at the bottom of a road cut. We can only make an educated guess at the original position in the matrix. For some localities the source is fairly well known and understood and for others it could be one of many possibilities.

My nephew collected a horse tooth in a small stream near his home here in Austin. The tooth is light in color with a slight blue tint. It doesn't look highly "fossilized" although it is a bit "heavy". I was collecting Cretaceous material from the creek bed so this was not that old. But there is about six feet of aluvium over the Cretaceous and it is mapped and labeled as Colorado River Terrace deposits approximately 10K in age. It is far from the current Colorado River (this is the Texas Colorado, not the one in that really big gully further west) and I quickly asked him to show me exactly where he found it. There was a tooth-shaped hole right at the contact with the Cretaceous chalk. I'm 99% sure he found an original North American horse tooth. Pre-European reintroduction. He then proceeded to find another one a week or two later but in the loose gravel not the cut bank. Although that one looks even more "fossilized" it was out of context and we labeled it's age with a large question mark.

Provenance is everything.

[Shellseeker]

Peace River is an amazing location where many of my assumptions prove incorrect. It is sometimes a raging flood, high tumble, large rock environment. and then fossil hunting in poor conditions for preservation finds this http://www.thefossilforum.com/index.php?/topic/54224-mystery-vert/. Not much of a discussion. We have not had Giant Armadillos anywhere for the last 10k years. But this vertebrae is pristine

There are a lot of fauna that just do not exist in Florida since before the Spaniards arrived. It always surprises me when I find a tooth that looks modern,but the animal no longer exists. (Pre-Equus small horse molar)

The modern ones (Horses, cows, pigs, dogs) may pick up the tanic staining of a black water river. Still you can recognize heavier fossilization or wear caused by water erosion. Everything else is suspect.

Edited April 28, 2015 by Shellseeker

[MegHunterDoug]

For what its worth, in 1960 a slime pit dam burst and flooded the alafia with phosphate material...in one of the creeks i search i find an over abundance of horse material....that dam burst killed 12.5 miles of the alafia and i read another occurred in 1968....I think a lot of the material resulted from the dam break....

[Harry Pristis]

2 hours ago, MegHunterDoug said:

For what its worth, in 1960 a slime pit dam burst and flooded the alafia with phosphate material...in one of the creeks i search i find an over abundance of horse material....that dam burst killed 12.5 miles of the alafia and i read another occurred in 1968....I think a lot of the material resulted from the dam break....

 

I don't understand what you're asserting here, Doug.  Did the floods kill a bunch of horses?  Killing the Alafia River surely doesn't imply the deaths of lots of farm animals, does it?

 

This thread uses the term "fossilize" in its various forms; but, "fossilize" is a nebulous term, often used as a substitute for "mineralize."  We've discussed here the difficulty of knowing how long mineralization takes in Florida rivers.  In fact, tooth enamel appears to remain enamel for a very long time.  Cementum will mineralize to some degree.

 

All the routine methods of dating the Alafia horse teeth are unreliable.  We're left with the probability of finding horse teeth in that stretch of river -- equally unreliable, since equus teeth are found in so many places.

[Boesse]

It's deja vu, we were discussing this in a separate thread on horse tooth fossilization. Fossilization is in itself, as @Harry Pristis correctly points out, loosely defined. It does not refer to permineralization, as many specimens that are naturally buried can retain collagen and other nonmineralized tissues for millions of years, in addition to escaping processes of mineral enrichment. As @erose also points out, staining and permineralization are completely different things that end up with a similar looking fossil, but have different processes and often would require chemical analyses to sort out for sure if looking at ex-situ specimens in a river.

 

One of the earliest decent creek specimens I found on the west coast was a large bovid radius which I thought was from the early Pleistocene Irvington Gravels - and thought it might be Euceratherium.  It even passed the burn test - no collagen. However, it was morphologically identical to a domestic cow, which on that part of the west coast is basically no older than 1800 or so - just a river stained modern cow bone.