Shark, Ray And Fish Micros From The Miocene Choptank Formation Of Virginia Trip 3

[MarcoSr]

I want to thank Rob for talking me to this site.

This matrix was taken from a different site and different zone of the Choptank Formation than my previous two Miocene Choptank Formation posts. Those were from zone 19 and I believe this matrix is from zone 16 of the Choptank Formation. The USGS is doing pollen studies to try to firm up the different zones in the Formations of Maryland and Virginia. I am working with a USGS emeritus who is studying and documenting the vertebrate faunas of these different zones. I will donate any specimens from this trip which are needed to support and further this effort.

I brought 4 gallons of raw, clay based matrix home. I dried this matrix really well on cookie pans in the sun and then put it in several buckets with hot water. This broke the matrix down pretty well. I then washed the matrix really well in a .4mm sieve, dried it, and then put it in 3% H2O2 to totally break it down. I wound up with about a cup and a half of residue that was almost totally fossil material. Although a lot of it was fish cartilage fragments, I did find a good number of shark, ray and fish micros in this residue. There was a nice variety of fish and ray teeth. However, although there were a good number of shark teeth, most were Carcharhinus or Mustelus. I’m posting the nicer and more unusual micros which I found. If you place your cursor on a JPEG image you will see the file name which will have the specimen id as best that I can determine and the specimen size.

Each matrix that I search makes me more of an avid micro tooth collector. If anyone has or can collect good matrix with shark, ray, and fish micros please send me a PM.

Shark Teeth:

Ray Teeth (Note some of these ray teeth have translucent crowns):

Continued in next reply.

Marco Sr.

[MarcoSr]

Fish Teeth:

Dermal elements (denticles/scutes):

Continued in next reply.

Marco Sr.

Edited October 3, 2013 by MarcoSr

[MarcoSr]

Some jaws (probably fish), a tooth, and a bone that I need id help:

Marco Sr.

Edited October 3, 2013 by MarcoSr

[busyeagle]

Neat finds and excellent photos as usual, Marco. I'm curious about what that unknown tooth could be.

[MarcoSr]

Neat finds and excellent photos as usual, Marco. I'm curious about what that unknown tooth could be.

If the tooth was solid, more triangular and flatter I might think it was Sphyraena because they can be serrated. However, I'm not aware of any other fish teeth from the Miocene that are close to it. So I'm really not sure what it is. It's not a shark or ray.

Marco Sr.

[PFOOLEY]

As always, great stuff Marco!

[Katfish61]

These are great micro finds, I too have some I want to post. I can't seem to get a good quaility picture of them. Any suggestions on that? I have been out of the fossil hunting game do to me falling last time I was at the creek. I did bring home two coffee cans full, cleaned it up and was amazed at all of the micro in it. Some I was able to ID and others, not so much. I finally got my book "The Collector's Guide to Fossil Sharks and Rays from the Cretaceous of Texas". I have learned so much from it and am still not sure on some things I came across......In due time, I will have it down. I found some very, very small Ptychodus. I am looking forward to sharing them with ya'll.....

[Auspex]

... can't seem to get a good quaility picture of them. Any suggestions on that?...

LOTS of light (sunlight can be best), and use the Macro Mode (tulip icon).

Plenty more here: LINK

[MarcoSr]

I can't seem to get a good quaility picture of them. Any suggestions on that?

I've been trying to get good images of micros for many years. I've tried different cameras, scanners and microscopes. I've found that a digital microscope that I can use through my computer to take pictures works the best for me. Plus I agree with Auspex that no matter what you use, that you want as much sunlight as possible. I look forward to seeing what you have found.

Marco Sr.

[Katfish61]

Thanks for the information, I will try it tomorrow. It's going to be a beautiful day, with lots of sunshine. I tried with the late afternoon sun and it didn't work. Thanks again!!

[BelemnBlues]

Hi Marco,

That sounds like an interesting project you are working on with the Choptank micros. Did you ever get an id on the unknown fish tooth? If not have you considered possibly a wahoo (Acanthocybium). Definitely some great finds.

Thanks

Luke

Some jaws (probably fish), a tooth, and a bone that I need id help:

Unknown tooth 2mm.jpg

Marco Sr.

If the tooth was solid, more triangular and flatter I might think it was Sphyraena because they can be serrated. However, I'm not aware of any other fish teeth from the Miocene that are close to it. So I'm really not sure what it is. It's not a shark or ray.

Marco Sr.

[MarcoSr]

Hi Marco,

That sounds like an interesting project you are working on with the Choptank micros. Did you ever get an id on the unknown fish tooth? If not have you considered possibly a wahoo (Acanthocybium). Definitely some great finds.

Thanks

Luke

Luke

I gave all of my micros from this formation to the USGS emeritus who was going to identify everything so I didn't do anything further with the ids. I didn't realize wahoo teeth were finely serrated. After just doing some web research I definitely agree on Wahoo. The shape of the tooth and the fine serrations definitely compare well to a bunch of modern wahoo teeth that I've just looked at. Thank you for the id help. It is really appreciated. I'll pass it on.

Marco Sr.