Florida Shark teeth

[Jdeutsch]

Is there a difference in the fossil shark teeth on the Atlantic coast vs the Gulf coast of Florida?

I'm not that familiar with the area, but it seems to me that there are many deposits of shark teeth on the gulf side, but not so much on the Atlantic side. At leat it seems like the area around the mouth of the Peace river attracts a lot of attention, but I never hear much about Daytona beach or Boca Raton.

The geologic maps look like the Atlantic coast is generally younger than the Gulf coast, but I don't know how that affects shark teeth findings.

[caldigger]

I'm thinking (and correct me if wrong), The Atlantic side will likely get more wave action, stirring things up and more sand deposited. There is a much stronger current on the Atlantic coast to move items away from areas of original deposition. It also depends on where the land was exposed during the different ages.

[Grimlock]

There is definitely a big difference when it comes to the types and ages of shark teeth on the Atlantic and Gulf coasts of Florida. Over on the Atlantic side here we get a lot more recent teeth. This is due to several factors. First, the age of the strata that we get here is much newer than on the Gulf. There is also a big difference in the depositional environments between the two. Caldigger is correct in that we get a lot more wave action here and our beaches are much more heavily eroded. So, things don't stay here as long as on the other coast and teeth we find are much younger. One exception is that since our beaches are so readily eroded we have to renourish our beaches. This consists of dredging sand from off the coast and dumping on the beach. This brings up stuff that has been collecting in deeper waters for a while. So, you can find things (teeth, shells, etc.) that are up to several hundred thousand years old, but that's about it. Another exception is around St. Augustine. There is a member here (sorry I don't recall their name, but look around and you'll find him) who has been finding some very impressive meg teeth while scuba diving off of there. I go up to St. Augustine once a year or so and have found some fossil material that in most likely Miocene- Pliocene in age.

Here are some of the teeth I have found very recently on a beach that was renourished several month ago. The age of these range from about 100,000 years old - recent. I have, however, found teeth on the beaches around here that are so new that the roots are still pink. Notice that these are generally in a lot better condition than most found on the Gulf.

On the Gulf side you will find much older teeth. There is also a lot more of them, having been collecting for millions of years. As opposed to the Atlantic, the wave action is significantly less and the condition is much more depositional. Along with the much older strata, this culminates in teeth that are older and in greater abundance. Not only is fossil material eroded out of the rivers in certain areas, but some of the same strata is exposed at spots along the coast (Venice and surrounding area). The teeth found on the beach are usually much more worn, but they can come in some wonderful colors. Although I don't get to hunt as much on the Gulf as I do over here, I have yet to find a recent shark tooth at the beach. I hope this helps.

[mrieder79]

If you are talking about me, Grimlock, I do all my diving in GA. I have only found a few small teeth in St. Augustine.

To answer the OP, the Jacksonville dredge piles are good hunting grounds. Unfortunately almost all specimens will be damaged. I have found several megs from Jax but all have lobes missing. Jax Beach also produces fair numbers of teeth. Most are small, though.

[Grimlock]

Yes I was talking about you. I'm sorry, I thought you were finding your stuff out of St. Augustine. Like I said, I have found fossil material washed up on the beach there and some of the locals said that they find some good teeth. It is definitely older that the stuff we get down here. I figured you had found a good pocket off shore somewhere. That half meg you just posted is beautiful by the way.

[Shellseeker]

I wish a Geologist would give some background, since I am not one. There are no dinosaur bones in Florida because it was well under water thru the Eocene. Pangaea, single continent, that starts breaking up and splits off "Florida" from Africa. As the continents sink, the land under the sea that will be Florida drops about 4000 feet, So maybe there are Pliosaur teeth 4000 feet down. So 30-40 million years ago parts of Florida starts rising up out of the Seas.

The continent that will be North America has a massive river flowing from the Appalachians and ending in Bone Valley dumping phosphates into mid-Florida south of present day Orlando and into the Gulf of Mexico. This river makes the Mississippi seem like a trickle. The Seas are relatively shallow between 20 and 200 feet, and the River delta is perfect for shark nurseries and coral reefs. There is little surprise that there are tons of shark teeth in south central Florida and the Gulf, that was the direction of river delta. There are Megs, Makos, Hemis and smaller sharks, and few GWs -- No RICs, Angys, but a few Chubs. Probably these teeth were dropped 2-20 millions years ago when the Megs reigned.

I think that the easy speculation is that the Atlantic did not have the outflow of that massive river delta attracting the sharks. I have a friend who finds massive numbers of large shark teeth by going scuba diving miles out into the Atlantic off the coasts of Georgia, North and South Carolina -- http://www.thefossilforum.com/index.php?/topic/56941-45-miles-out-and-85-feet-down/

We might wonder what the Shark teeth are doing there --- why was that a spot that sharks congregated. Wouldn't it be wonderful if we had that time machine?

[Auspex]

From a collector-centric standpoint, there are three basic things that need occur:

The environmental conditions had to be shark-worthy in the first place, and then it helps to have a high rate of sediment deposition to inter and preserve the remains. Finally, those sediments must be made available by erosion for collector access.

[Jdeutsch]

Are fossil shark teeth found along the keys?

[digit]

Are fossil shark teeth found along the keys?

I've never encountered any or heard of any outcrops in the Keys where fossil shark teeth can be found. For that matter, in all of my years of diving (possibly more than I'd care to admit) I've never once come across a non-fossilized (recent) shark tooth while diving. I've been in places with large aggregations of sharks many times and while I occasionally scan the shell hash in sand channels nearby (where I'd expect them to accumulate) I've never found a single one. Makes me appreciate the concentrating powers of a river like the Peace to slice through large amounts of fossil bearing matrix and aggregate the teeth at a density that is worth the effort of hunting for them.

Cheers.

-Ken

[Shellseeker]

Are fossil shark teeth found along the keys?

An interesting question: I live off Fort Myers, about 50 miles south of the accumulations of shark teeth off of Venice and basically no shark teeth. As much as we discuss fossils from Florida, in most of the state, there are none. See Auspex insightful comment above.

I would be glad to be corrected. I have walked the beaches of the Keys -- no shark teeth.

[Grimlock]

I haven't been to the Keys in years, so I can't say with any certainty, but I would bet you could find some modern shark teeth around the reefs out there. You would have to sort or sift them out from the rest of the shell litter. Just scanning the bottom, it would be like finding a specific needle in a mountain of needles. I have to agree, however, that I have never found a shark tooth on a beach down there. Maybe it has something to do with the way the deposition of sediment is there, it would stand to reason that a lot of the stuff that is dropped around there might get brought North by the Gulf Stream.