Micro Fossils From Greens Mill Run

[John Hamilton]

The attached fossils were found in matrix I collected from Greens Mill Run earlier this year. If anyone can provide positive ID's on anyof them it would be greatly appreciated.

1. Ptychotrygon vermiculata rostral tooth?

2. Lonchidion cf babulskii or a very worn nurse shark?

3. unknown?

4. unknown?

5. unknown?

As always thanks for looking!

After further research I feel item #2 is just a worn nurse shark tooth.

Edited July 27, 2013 by John Hamilton

[Al Dente]

I think you are right with the first one, at least that is what Case and Schwimmer called these things.

#2 might be Cantioscyllium, #3 looks like a pychnodont fish tooth, and I think #4 and 5 are Pseudohypolophus.

[masonboro37]

Wish I could help you with id's. Your specimens are I have to say are remarkable. I have only been there one time, hoping to go back in a few weeks. I am entranced by micro's and thanks for sharing these!

[John Hamilton]

I think you are right with the first one, at least that is what Case and Schwimmer called these things.

#2 might be Cantioscyllium, #3 looks like a pychnodont fish tooth, and I think #4 and 5 are Pseudohypolophus.

Al,

Thank you for the feed back.

[squali]

Wow John very cool specimens. Thanks for sharing. Quick question. Did you sample stream bed or is there a visible strata exposed that you sample from.

[John Hamilton]

Wish I could help you with id's. Your specimens are I have to say are remarkable. I have only been there one time, hoping to go back in a few weeks. I am entranced by micro's and thanks for sharing these!

Abbey,

Thank you. I was bitten by the micro bug after my first trip to the Aurora fossil museum. The thing I enjoy most is that no matter what the weather is like or what time of year you can hunt fossils. I wish you luck on your next trip to GMR. Hopefully the water levels will be low enough to allow you to hunt. Just make sure to keep an eye out for the wildlife. My wife and I encountered a brown water snake on our trip last week. Even though they are non venomous they can be quite a surprise when they pop up from under water or drop from a tree branch.

[John Hamilton]

Wow John very cool specimens. Thanks for sharing. Quick question. Did you sample stream bed or is there a visible strata exposed that you sample from.

Squali,

I use an inexpensive set of gold classifiers to remove the larger cobble and collect the matrix directly from the stream bed.

[MarcoSr]

John

Nice micro specimens. I am not convinced that the experts have done a very good job at identifying the sawfish rostral teeth. They can look very similar and can change along the rostrum. Unless you find complete or associated sawfish specimens like they sometimes do in Lebanon or Morocco, where the rostral and oral teeth are actually found together, the identification of rostral teeth with oral teeth can be really speculative. What really causes me problems with some of the identifications is there are sites where I only find the oral teeth, and sites where I only find the rostral teeth of a specific species. This is very possible but still puts doubt in my mind. Plus I see some patterns where I always seem to find certain oral teeth with other rostral teeth but they are identified as different species.

When I took matrix from the sand bars at Greens Mill Run, I also picked up a bunch of very small clams which I didn't realize at the time. Luckily I looked through the matrix right away because the clams had died and were already starting to smell. Did you have the same problem? If not, did you take your matrix from deeper water versus from the sand bars? I would like to take more matrix the next time I'm there but don't want to kill the native life like the small clams.

Marco Sr.

[John Hamilton]

John

Nice micro specimens. I am not convinced that the experts have done a very good job at identifying the sawfish rostral teeth. They can look very similar and can change along the rostrum. Unless you find complete or associated sawfish specimens like they sometimes do in Lebanon or Morocco, where the rostral and oral teeth are actually found together, the identification of rostral teeth with oral teeth can be really speculative. What really causes me problems with some of the identifications is there are sites where I only find the oral teeth, and sites where I only find the rostral teeth of a specific species. This is very possible but still puts doubt in my mind. Plus I see some patterns where I always seem to find certain oral teeth with other rostral teeth but they are identified as different species.

When I took matrix from the sand bars at Greens Mill Run, I also picked up a bunch of very small clams which I didn't realize at the time. Luckily I looked through the matrix right away because the clams had died and were already starting to smell. Did you have the same problem? If not, did you take your matrix from deeper water versus from the sand bars? I would like to take more matrix the next time I'm there but don't want to kill the native life like the small clams.

Marco Sr.

Marco,

I had the same experience with the fresh water mussels the first two times I took matrix home. Now I use an inexpensive set of gold classifiers/sieves to prevent bringing home the mussels and the larger gravel. I have attached a link for the gold classifiers below.

http://www.amazon.com/dp/B0089OKEUK/ref=pe_385040_30332200_pe_309540_26725410_item

[MarcoSr]

Marco,

I had the same experience with the fresh water mussels the first two times I took matrix home. Now I use an inexpensive set of gold classifiers/sieves to prevent bringing home the mussels and the larger gravel. I have attached a link for the gold classifiers below.

http://www.amazon.com/dp/B0089OKEUK/ref=pe_385040_30332200_pe_309540_26725410_item

John

Thanks for the link. The gold classifiers should solve the problem with the mussels.

Marco Sr.