Several Questions

[Mudduck]

Ok, I have several questions and thought this would be the best place to post them.

1st Q:

I get the questions as to the age of my finds. I am Charleston, South Carolina and everything I find is a Land Find. How can I tell what the age I am looking in. I find Angy's, Megs, Great Whites, Mako's, Hemi's, Threshers, Tigers, but I also find some mammal teeth from time to time. I also look for the gravel as for signs to hunt for fossils. Sometimes items are all by themselves with nothing else around to identify where I am looking.

2nd Q:

The difference between a Ric' and a Angustidens? What is the difference between the two? I really find it hard to believe that a Ric' only swam in one certain area and deposited teeth. It could be the layer is deeper..I don't know.

3rd Q:

Is there a link to show what sharks lived during a certain time frame. (Mammals as well).

4th Q:

Is the lineage between the relationship between shark based on fact or theory? Example, Angustidens to the Meg?

Thanks, I really learn a lot from this forum and have learned a lot from the members here.

[CH4ShotCaller]

I had the same questions when we lived in Myrtle Beach long ago. Couldn't accept the notion that I could find a meg around Murrells Inlet that had a mastodon tooth lying a foot away and turn around and find another tooth 90my older than the other finds. I just thought the inlet was cutting through many layers. Unsure of the Charleston area, but I need to take a vacation back that way to escape the rain for a wee bit.

[cowsharks]

Mudduck, here's an indirect answer to some of your questions: Low Country Excursions

I bet if yo uwere to arrange to go on a trip with these folks they could answer most of your questions while showing you in person.

Next, take a look at the teeth on this site (BTF). You'll see a variety of teeth from SC there. Below text is taken from this BTF site.

"South Carolina is well known for an abundance of shark teeth from the Carcharocles genus – the extinct Giant White sharks. Three different localities are featured.

The rivers of coastal S. Carolina are home to Carcharocles megalodon, the extinct Giant White shark. Teeth are recovered in gravel holes at the bottom of these rivers. Divers must fight off rapid currents and little to no visibility in water depths of 30-60 feet to find their prize. These teeth are Miocene-Pliocene in age (2-15 million years ago), but typically come from the Miocene Hawthorne Formation (15 million years ago).

Marl deposits in the Dorchester county area yield excellent specimens of Carcharocles angustidens – another extinct Giant White shark ancestor. Thresher, Angel, and other shark teeth also in these deposits. These teeth are Oligocene in age (25-38 million years ago) from the Chandler Bridge Formation.

Numerous limestone quarries in the Dorchester-Orangeburg counties area have yielded superb specimens of Carcharocles auriculatus – the precursor of the extinct Giant White shark. These fossil teeth are found in the Santee limestone which is Eocene age (38-45 million years ago). These quarries also yield the exquisite teeth for the Cow shark, Hexanchus agassizi and the earliest Mako shark, Isurus praecursor.

Cow, Tiger, Dusky, and Megalodon shark specimens come a new land site near Ridgeville, SC. These beautifully colored teeth are from the Pliocene epoch (approx. 4 million years ago). "

Hope this helps a bit.

Daryl.

[Mudduck]

It helps somewhat. I am in Charleston County but I don't hunt the rivers. I find all the teeth above but in one location along with some mammal teeth. Maybe I am in a mix between the two and get the best of both worlds! Besides, I know that they find Angustidens in the river also. So when I post an unknown tooth, the first question is "What Age?". I guess until an expert arrives to my location and surveys the area to identify, it would be speculation. I am sure the mammal teeth would be the most recent or could be the oldest...?

Thanks Daryl for your input.

[Auspex]

If your mammal material is from terrestrial critters, they are probably more recent (Ice Age), deposits on top of the (then old and now high and dry) marine deposits with shark's teeth and such. A little erosion, a little mixing, and you have both.

[sixgill pete]

Mudduck, let me try to help you. One of the quarry's I hunt is mostly Eocene, Castle Hayne formation. However there are underlying Cretaceous layers and overlying Miocene, Pliocene and Pleistocene layers. In other words, I can find auriculatus and megs, same place, different layers. When you have the time try doing a search on the geological makeup of your area. Remember many areas of the east coast were underwater, then dry, then under, while others were underwater from the Cretaceous until the Pleistocene. Learning about this for your area will help you to understand why you find, what you find. When I started becoming serious about this hobby I was in the same boat, I just didnt understand why I was finding teeth from different era's at the same locations. Sometimes, I still do not.

[Mudduck]

Didn't think about being under water they dry then underwater back to dry again. Interesting perspective. I have found sites but it doesn't really explain that I am finding what I am finding. I had tried to contact an expert via email here in Charleston but have not gotten a reply. Maybe I need to try again.

Thanks guys!

[donckey]

You are finding what you are finding and want an explaination for it. You got some wise answers and still want more (better?) explainations.

What exactly do you want to know?

[siteseer]

Those are tough questions to answer with a couple of sentences each or even with a link to a helpful website but consider the following as another launching point along with the answers you've already been given:

1st A: You need to familiarize yourself with what is found per time interval available in your collecting area. For you, that means you want to know what animals are found in the Eocene, Oligocene, Miocene, Pliocene, and Pleistocene. You might even want to familiarize yourself with the animals that live there today so you don't mistake a modern pig tooth from an Ice Age peccary. Some animals lived only during one epoch but some survived across more than one.

Because you find fossils across the Eocene-Pleistocene, you need a reference that allows you to look at fossils from sites that have been narrowed down in age not just to within a Cenozoic epoch but to what part of that epoch. A good reference for that for fossils of your general region is "The Fossil Vertebrates of Florida" edited by Richard C. Hulbert Jr. Some Florida sites are like SC sites in that more than one age may be represented but many contain fossils from one particular geologic moment. The fossils found in Florida also range from Eocene to Pleistocene so you luck out in that way. You will want to keep your eyes open for other publications on sites in your region where the age has been narrowed down to within an epoch.

2nd A: If you do a search for "auriculatus" and "angustidens" just within this website, you will find information on both. The quick answer is that auriculatus is the Eocene ancestor of angustidens which is generally considered an Oligocene shark and auriculatus had generally a thicker crowned, thicker rooted teeth with more robust side cusplets than angustidens. Of course, that means some Late Eocene or Early Oligocene teeth may be more difficult to nail down to species.

3rd Q: There is a nice chart in Appendix C in the book "Fossil Sharks of the Chesapeake Bay Region" by Bretton W. Kent which places a variety of shark species in time and formation (Cretaceous to Recent) and the book would also help you with identification since many of the species are also known from SC localities. The Hulbert book provides age ranges for a variety of vertebrates (Chapter 3), including mammals, as they are known from Florida but the age ranges would be largely applicable to other areas as well.

4th Q: Extinct sharks are mostly known only from teeth so its difficult to hammer out a family tree with the same small margin of error as for a group like mammals of which whole skeletons are found. Still, the teeth of angustidens can be linked taxonomically to megalodon because of their great similarity and because teeth of intermediate form have been collected from layers of intermediate age (Late Oligocene to Middle Miocene).

1st Q:

I get the questions as to the age of my finds. I am Charleston, South Carolina and everything I find is a Land Find. How can I tell what the age I am looking in. I find Angy's, Megs, Great Whites, Mako's, Hemi's, Threshers, Tigers, but I also find some mammal teeth from time to time. I also look for the gravel as for signs to hunt for fossils. Sometimes items are all by themselves with nothing else around to identify where I am looking.

2nd Q:

The difference between a Ric' and a Angustidens? What is the difference between the two? I really find it hard to believe that a Ric' only swam in one certain area and deposited teeth. It could be the layer is deeper..I don't know.

3rd Q:

Is there a link to show what sharks lived during a certain time frame. (Mammals as well).

4th Q:

Is the lineage between the relationship between shark based on fact or theory? Example, Angustidens to the Meg?

Edited January 5, 2013 by siteseer

[Mudduck]

Thanks for the recommendations and responding. I have been to the book store and have yet to find a good book on fossils. I am looking for my are specifically. I will check those out. Time for a little bit of homework.

Thanks again.

[Mudduck]

You are finding what you are finding and want an explaination for it. You got some wise answers and still want more (better?) explainations.

What exactly do you want to know?

I get the question "What Age", when I show or post items that I find. I have no clue as to the age. The previous post included the rivers of Charleston and also Dorchester County, I am in between. Siteseer has answered a lot of questions along with the others. What I need to do is do some homework and study the area that I am in and pay real close attention to the items I do find and try to match them to the correct period. I am learning a lot just by asking questions. Thanks.

[Auspex]

There's a real Catch 22 to deal with, when you need the age to determine the species, but you have to know the species to determine the age...

This is where reverence for "guide fossils" comes from; they are widely distributed, and known to be from a very narrow geologic time frame. Even then, fossils that are collected from eroded, reworked sites (as opposed to being dug out of virgin strata) don't have that positive age/formation info written on them, so it takes a lot of work and a huge sample size to get a handle on what's going on geologically.

But then, that can be at least half the fun