Onslow Strange Tusk-Like Fossil And Possible Mamman Tooth?

[tracer]

Hoffy--sometimes when the kids are fighting, I have to step in and solve the mystery that started it all. I am the Final Word. The Press often refers to me as"perhaps the most important paleontologist of our time."

you left out the final clause, "...specializing in analysis of lower-cretaceous periprocts."

but you are one of the funnier guys on the planet.

[BobC]

TRACER!!! My case of periprocts cleared up long ago after that trip to the free clinic. I told you that. Can we get back to the Cretaceous dugong antlers now? 3oo million years ago, when modern man first slithered out of the primordial ooze, they often used the dugong antlers to scratch those hard-to-get-to spots on their hairy, ape-like backs.

[JohnJ]

That's how it is around here. Learn a little, laugh a little...you guys are killin' me!

[Guest Smilodon]

"perhaps the most important paleontologist of our time."

Bob, as "perhaps the most important paleontologist of our time," then you know darn well that dugongs don't have antlers. But they do have tusks. Someone could actually google that on their own if they wanted to be sure.

[BobC]

Then what did the Cretaceous people use as back-scratchers, Mr. Smartypants?

Oh and I suppose next you'll tell us that the robin wasn't the first bird.

[siteseer]

Man look what you got started lol you have a rib and a horse tooth what everyone failed to think about is WE DON'T FIND DUGONG RIBS IN NORTH CAROLINA OFTEN so many of us including me have made the ivory mistake you have to admit guys they do look mighty ivory like if you've never seen them especially like the one I posted a couple of weeks ago from the same spot with a mastodon molar fragment laying not 2 feet from it.

Ozzyrules244,

Daryl mentioned the River Bend Formation as a possible source, adding that angustidens and megalodon teeth were also found. The River Bend pretty much spans the Oligocene and angustidens is known from the Oligocene to Early Miocene so a dugong could be from that formation. The megalodon occurrence indicates that a Miocene or perhaps Early Pliocene layer is also being sampled. Your find of a mastodon molar certainly points to another layer as mastodonts don't appear in North America until at least the Middle Miocene.

It could be that dugongs were rare in the Carolinas during the Oligocene-Miocene. A few teeth have been found in the Mid-late Eocene limestone quarries around Harleyville. You are much more likely to find a rib section than any other part of the skeleton. We find rib pieces in the Lower Santa Margarita Formation but teeth are very rare. I've seen quite a few Bone Valley dugong teeth but some longtime Bone Valley collectors could build a fence with all the rib sections they have found (most people leave them after already having a boxfull at home). Years ago, I saw a nice dugong jaw with two teeth from the Cooper River, SC.

[Guest Smilodon]

A friend and one of the many dugong skeletons he found in Bone Valley over the years - probably in the 70s. Love the 'fro too

[gregg]

Gregg--how old are the ribs you find? I'm just curious

Plio-pleistocene. Peace river material near Arcadia.

[BobC]

Cool--thanks

[Harry Pristis]

BobC, on 17 February 2010 - 07:27 PM, said:

Gregg--how old are the ribs you find? I'm just curious

Plio-pleistocene. Peace river material near Arcadia.

Because these dugong ribs are found mixed with Pleistocene fossils does not mean they are of the same age. Remember that they are also mixed with Miocene shark teeth.

In fact, the vast bulk of dugong material found in the Peace River is Miocene in age, washed out of the Miocene phosphatic clay. There is one Early Pliocene dugong known.

There is only one Late Pliocene dugong, undescribed, from the Caloosahatchee Fm in Sarasota County. The Caloosahatchee is not exposed in the upper Peace River. There are no Pleistocene dugongs known.

[Boesse]

While these sirenian ribs are all most likely Miocene dugongids... there are Pleistocene manatee fossils from Florida and the like.

[Harry Pristis]

While these sirenian ribs are all most likely Miocene dugongids... there are Pleistocene manatee fossils from Florida and the like.

Florida and the like are known to have manatee fossils, yes. That's a vague remark that can only confuse some readers. What's your point regarding Peace River sirenian ribs?

[Guest Smilodon]

While these sirenian ribs are all most likely Miocene dugongids... there are Pleistocene manatee fossils from Florida and the like.

There is Eocene and Oligocene sirenian material as well from Florida but not from the Peace River.

Edited February 19, 2010 by Smilodon

[Boesse]

Florida and the like are known to have manatee fossils, yes. That's a vague remark that can only confuse some readers. What's your point regarding Peace River sirenian ribs?

Not sure how that's vague and confusing. There are Pleistocene (i.e. 2.5-0.1 Ma) manatee (i.e. Trichechus) fossils from that general area. I.e. dugongids are not the only sirenian fossils out there... manatees also have pachyosteosclerotic ribs, and fragments cannot be properly identified past "sirenia". So - since everything in the Peace River is reworked as it is, thus some sirenian ribs actually have the potential to be pleistocene. Bobby

Edited February 20, 2010 by Boesse

[gregg]

BobC, on 17 February 2010 - 07:27 PM, said:

Gregg--how old are the ribs you find? I'm just curious

Because these dugong ribs are found mixed with Pleistocene fossils does not mean they are of the same age. Remember that they are also mixed with Miocene shark teeth.

In fact, the vast bulk of dugong material found in the Peace River is Miocene in age, washed out of the Miocene phosphatic clay. There is one Early Pliocene dugong known.

There is only one Late Pliocene dugong, undescribed, from the Caloosahatchee Fm in Sarasota County. The Caloosahatchee is not exposed in the upper Peace River. There are no Pleistocene dugongs known.

The ribs and other dugong material were pulled from situ. There is a shelf of material about two hours paddling upstream from the Peace River Campground in Arcadia. The shelf is a type of limestone (in solid form reacts with HCl). I have never tried to get the age for the site. I always assumed it was at the plio-pleistocene boundary.

Well, it just goes to show you can learn something new every day!! Thanks, Harry, for taking me to school I better go and change the date on the tags I put on the other fossils from that site!!

[tracer]

Not sure how that's vague and confusing. There are Pleistocene (i.e. 2.5-0.1 Ma) manatee (i.e. Trichechus) fossils from that general area. I.e. dugongids are not the only sirenian fossils out there... manatees also have pachyosteosclerotic ribs, and fragments cannot be properly identified past "sirenia". So - since everything in the Peace River is reworked as it is, thus some sirenian ribs actually have the potential to be pleistocene. Bobby

bobby - they're pachyostotic but not sclerotic, in that there's no pathology involved. as far as i know...or is there such a thing as non-pathological sclerosis?

[Harry Pristis]

The ribs and other dugong material were pulled from situ. There is a shelf of material about two hours paddling upstream from the Peace River Campground in Arcadia. The shelf is a type of limestone (in solid form reacts with HCl). I have never tried to get the age for the site. I always assumed it was at the plio-pleistocene boundary.

Well, it just goes to show you can learn something new every day!! Thanks, Harry, for taking me to school I better go and change the date on the tags I put on the other fossils from that site!!

'Smilodon' is correct to point out that there are dugong fossils from the Eocene and the Oligocene, as well as from the Miocene of Florida.

The bedrock of the Peace River valley is the Tampa Limestone, a fairly-indurated (compared to Ocala Group limestone) limestone containing silicified invertebrate remains (think Tampa Bay agatized coral). The Tampa age is Early Miocene at about 25 Ma. The Tampa limestone is usually easy to identify because, on water-worn exposures, the silicified invert material will tend to shred your gloves (or your skin).

Any dugong bones that you found in situ in the Tampa limestone might have to be laboriously removed from the rock, I think. Bobby might argue that "anything is possible," and it is. But, I think that later Miocene (Hawthorn) and Mio-Pliocene (less likely) deposits are more-reasonable possibilities.

Edited February 20, 2010 by Harry Pristis

[gregg]

Any dugong bones that you found in situ in the Tampa limestone might have to be laboriously removed from the rock, I think. Bobby might argue that "anything is possible," and it is. But, I think that later Miocene (Hawthorn) and Mio-Pliocene (less likely) deposits are more-reasonable possibilities.

Isn't the Hawthorn strongly clay based? I know in Central Florida it is the aquiclude that most of our springs flow through. This seemed a lot less consolidated than clay. The bones came out with only minimal work. I'll need to find the box that has my rock specimens from that area and have them checked out.

[ozzyrules244]

As I said LOOK WHAT YOU GOT STARTED DARYL I have certainly gotten many laughs out of this post I cant believe people are still talking about this one Call it a rib and run Daryl haha even though it doesn't look like the ribs I have now that I have seen it in person but I will go with rib since the experts say it is or go one one step further and say (it is what it is dude) I really do Think you should listen to John he is really a wealth of knowledge!!!!! I can't wait till we clean and prep our Triassic plant fossils from yesterday's hunt and post the pics I wonder what we can get started on those and no people I have absolutely no idea what the plants are but I do know there are experts in here that do!

[Boesse]

'Smilodon' is correct to point out that there are dugong fossils from the Eocene and the Oligocene, as well as from the Miocene of Florida.

The bedrock of the Peace River valley is the Tampa Limestone, a fairly-indurated (compared to Ocala Group limestone) limestone containing silicified invertebrate remains (think Tampa Bay agatized coral). The Tampa age is Early Miocene at about 25 Ma. The Tampa limestone is usually easy to identify because, on water-worn exposures, the silicified invert material will tend to shred your gloves (or your skin).

Any dugong bones that you found in situ in the Tampa limestone might have to be laboriously removed from the rock, I think. Bobby might argue that "anything is possible," and it is. But, I think that later Miocene (Hawthorn) and Mio-Pliocene (less likely) deposits are more-reasonable possibilities.

Yes, bones that originate from carbonate units would be pretty difficult to erode out - however, the process of phosphatization does dissolve calcium carbonate (on a small scale, anyway). So while it is certainly possible that in an upwelling regime associated with phosphogenesis (as has characterized the Atlantic shelf since at least the the late Miocene) the limestone matrix could be preferentially dissolved (which has been documented as a mode of bonebed formation in the literature) it is far more likely that the limestone would phosphatize and form a hardground or rockground. Bobby

[Harry Pristis]

Yes, bones that originate from carbonate units would be pretty difficult to erode out - however, the process of phosphatization does dissolve calcium carbonate (on a small scale, anyway). So while it is certainly possible that in an upwelling regime associated with phosphogenesis (as has characterized the Atlantic shelf since at least the the late Miocene) the limestone matrix could be preferentially dissolved (which has been documented as a mode of bonebed formation in the literature) it is far more likely that the limestone would phosphatize and form a hardground or rockground. Bobby

It was not an "upwelling regime" that produced the phosphates in South Florida AFAIK. The phosphates originated in older deposits that were uplifted in the north (Ocala Uplift). The pebble phosphate in the south originated as "hardrock phosphate." The phosphate was transported south into a shallow bay (I think of it as a proto-Tampa Bay) as thousands of feet of carbonates were eroded from the uplifted area.

In fact the first phosphate boom to hit Florida in the late 1800s was at Dunnellon, Marion County, just a few miles from me. It's a hardrock phosphate up here, so when pebble phosphate was discovered in the bed of the Peace River, the mining effort shifted south. Dunnellon went bust.

That's a sketch of my understanding.