My Process for Searching through Micro Matrix from Bakersfield, California and the Large Amount of Fossils Found.

[Nimravis]

Fair warning on this post; it is not intended to have great pictures or exact identifications for the fossils that you are about to see. Rather it is the lengthy process that I go through when I search through matrix that I receive from Doren @caldigger and more importantly the great number of fossils that I find. Lastly, this post will not be completed today and will take a while since the process is still on going. I hope you enjoy it as much as I do while searching this stuff.

 

Doren knows that I do like searching through micro matrix, but I absolutely love searching through the Mid-Miocene / Temblor Formation / Round Mountain Silt Member bone bed material that he collects from Bakersfield, California. For the past couple of years he has sent me material to search in the Winter since it is too cold to crack open Mazon Creek concretions outside. Nothing makes my Winter than getting a package from him and knowing that I will be occupied 1-2 hours a night for several weeks. Thanks again, Doren. What makes this material different than the majority of matrix that I have searched is that it comes directly from a bone bed and teeth, bones, etc. become fossils over time.

 

I also want to thank @MarcoSr for his post on the ID’s for fossils from that area. Once again, I am not stating that everything is correct with my identifications and I can guarantee that I am missing a number of species, but that is not the purpose of this post. With that said, let’s move on.

 

I received these these 2 bags of matrix that fit perfectly inside a small USPS Priority box on or around 2-13-20.

 

 

Once I open these packages I pour them into 4 sifters (I do not use the 1/2" sifter) that are set on top of a 5 gallon bucket. The sifters that I use for this process are in the following sizes:

 

1/4" (.250")

1/8" (.125")

1/12" (.083")

1/20" (.050")

 

 

Once I pour the matrix into the top (largest) sifter, I shake it around so the pieces are somewhat organized by size. The below pictures shows how the matrix looks from 3 of the sifters.

 

 

I then begin my search, starting with the largest tray. This is the easiest tray to search, since not many fossils are found in it. I search through each tray using this Luxo brand magnifying light and a pair of tweezers. Searching the first 3 trays is not too hard, but searching the 4th tray takes a very long time since the fossils are so small, but the numbers in tray 3 and 4 are huge.

 

 

 

 

After I search each tray for the fossils, I organize them by species, with the exception of most shark teeth, I organize those by broken and complete or near complete. I then place each fossil in a compartment type tray by species.

 

 

Now let's move on to what I found in the first 2 trays.

 

TRAY 1-

 

Myliobatis (Total found 3)

 

 

Complete or near complete shark teeth- (Total number found 18)                                      Broken  shark teeth (Total number found 6)

 

 

 

TRAY 2-

 

Squalus- (Total number found 56)                                                                                         Squatina- (Total number found 59)

 

 

 

Misc Shark teeth- (Total number found 62)                                                                     

 

 

 

 Misc. broken Shark teeth- (Total number found 90)

 

 

 

Myliobatis- (Total number found 74)                                                                                            Myliobatis- (Total number found 22)

 

 

 

Dasyatis- (Total number found 37)                                                                                            Dermal Skutes- (Total number found 9)              

 

 

 

Verts- (Total number found 11)                                                                                              Heterodontus or Triakis or something else?- (Total number found 2)

 

 

 

 

My favorite teeth to find Cetorhinus- (Total number found 10)                                          Heterodontus- (Total number found 1)

 

 

 

The last thing that I found in Tray 2 was the below pictured piece, I found several broken, but only 1 that looked complete. Doren told me what he thought it was, but I forget. This is the first year that I have come across these in the matrix.

 

 

 

After I am finished with a search of the unwashed matrix that comes from each tray, it is time for the soaking and rinsing. I place the matrix into a large plastic bottle and I fill it with very hot water and then agitate it around for several minutes.

 

 

 

I then strain it with a small strainer and rinse it out. 

 

 

When I finish this, I place the matrix back into the bottle and again fill it with hot water, agitate it and let it sit for a couple of days before I do that process all over again. When I am satisfied that the matrix is very clean, I place the different sizes onto trays so it can dry thoroughly. Below are pics from tray 2 and tray 3. This matrix has not been searched again, since I am still searching the unwashed matrix from tray 4, the smallest stuff. If my cleaning was done correctly , I will be pulling a lot of fossils out of this stuff once I re-search it.

 

         TRAY 2                                                                                                                                                

 

 

TRAY 3

 

 

 

 

Later today I will try to post pictures and the number of fossils found in Tray 3. There are some big numbers coming, and then I have to finish searching tray 4 and start the process over again, so check back.

 

 

 

 

 

 

 

 

 

 

 

 

[Tidgy's Dad]

Very interesting and incredibly productive and that's just so far! 

You're going to end up with thousands of pieces just from those couple of bags.

Wow! 

[Nimravis]

23 minutes ago, Tidgy's Dad said:

Very interesting and incredibly productive and that's just so far! 

You're going to end up with thousands of pieces just from those couple of bags.

Wow! 

This is true Adam.

[caldigger]

I may add, the matrix went through 6 wash cycles before I even sent it to him.

A 24-36 hour initial soak in a bucket, then 4 separate hot water wash cycles before it goes into a 24 hour Hydrogen Peroxide soak, it gets rerinsed. Then thoroughly air dried for close to a week before it is packaged up.

It is unfortunately a quite lengthy and messy cleaning process with a low yield amount ( 5 gallons of raw sifted matrix whittles down to about 1/2 gallon) when finished.

But it is a high yield fossil wise matrix.

 

[MarcoSr]

Really interesting.  Nice specimens.  What do you do with what falls into the 5 gallon bucket?  1/20" (.050") is 1.27 mm.  A number of species like Mustelus, Triakis, Raja, Rinobatos, Gymnura etc. and fish teeth and placoid scales/dermal denticles will fall through .050".

 

 

The below teeth look like male Dasyatis:

 

 

 

 

Some examples of male Dasyatis (2 mm, 2 mm, 3 mm) to compare your specimens to.  Note these came from matrix from the Whale Pit on the Ernst Ranch which is why they are a different color.

 

 

          

 

 

Note two of these look like fish teeth:

 

 

 

 

Marco Sr.

 

 

 

 

 

[Coco]

10 minutes ago, MarcoSr said:

The below teeth look like male Dasyatis:

 

 

I thought the same thing.

 

Coco

[caldigger]

30 minutes ago, MarcoSr said:

What do you do with what falls into the 5 gallon bucket?  1/20" (.050") is 1.27 mm.  A number of species like Mustelus, Triakis, Raja, Rinobatos, Gymnura etc. and fish teeth and placoid scales/dermal denticles will fall through .050".

Sorry, but if I can't see it under 10x magnification, it goes back to Ma Nature.

[MarcoSr]

38 minutes ago, caldigger said:

Sorry, but if I can't see it under 10x magnification, it goes back to Ma Nature.

 

Doren

 

You can actually see small stuff down to .5 mm with 10X.  Below is a small sample of what is falling through 1/20" (.050") mesh.  The problem is that it takes a long time to look through this really fine matrix and it does become tedious.  I usually only look through enough really fine matrix to find the more common species in a fauna when I'm searching for my collection.  When I'm helping with a vertebrate fauna study of a formation layer/zone I have to look through a lot of this really fine matrix to try to find everything that I can that is in the fauna.  I have hundreds of baggies of really fine matrix from all over the United States and the rest of the world that I stopped searching when I found a decent sample of these really small specimens.

 

 

 

 

 

Marco Sr.

[caldigger]

Marco, I have very poor eyesight, and get horrible headaches trying to see the things that are readily visible as it is.

That's why I don't do the matrix searching and let you gleen the fruits of my labor.   

[hokietech96]

So cool  what a great project!

[Al Dente]

5 hours ago, Nimravis said:

 

The last thing that I found in Tray 2 was the below pictured piece, I found several broken, but only 1 that looked complete. Doren told me what he thought it was, but I forget. This is the first year that I have come across these in the matrix.

Can we see the other side? Looks like it could be a brachiopod.

[Nimravis]

17 minutes ago, Al Dente said:

Can we see the other side? Looks like it could be a brachiopod.

Here you go- it is concave and wafer thin.

 

[Nimravis]

2 hours ago, MarcoSr said:

What do you do with what falls into the 5 gallon bucket? 

Marco to be honest with you, not much falls to the bottom of the bucket, once I finish searching the finest matrix, I will have a lot more to post.

[Bobby Rico]

Very interesting and thanks for the informative post. I also have had a couple of small bags for Doren in fact it was my first trip to the world of micro matrix  . I don’t have any sifters maybe I will have to gets some. Both Mrs R and myself can spend hours searching, it pretty addictive and we usual search the matrix about 3 or 4 times.  
 

All the best Bobby

[Al Dente]

24 minutes ago, Nimravis said:

Here you go- it is concave and wafer thin.

 

Yep, it’s an inarticulate brachiopod.

[Nimravis]

Here are my finds and numbers from TRAY 3 (1/12" / .083")

 

Dasyatis- (Total number found 507)

 

 

Verts.- (Total number found 38)

 

 

 

I think that this is a mixture of possible Heterodontus, Triakis or Male Dasyatis. (total number found 109)

 

 

 

Broken Shark Teeth- (Total number found 90)

 

 

 

Myliobatis- (Total number found 35)

 

 

Myliobatis- (Total number found 28)

 

 

 

Cetorhinus- (Total number found 29)

 

 

 

Squatina- (Total number found 35)

 

 

Dermal Skutes and Denticles- (Total number found 32)

 

 

 

Complete or near complete Shark Teeth- (Total number found 10)

 

 

 

Mustelus- (Total number found 8)

 

 

 

Heterodontus- (Total number found 7)

 

 

 

I will continue this post one I finish searching TRAY 4.

 

For a running TOTAL, I am at 1389 fossils found so far.

 

 

 

[Nimravis]

3 minutes ago, Al Dente said:

Yep, it’s an inarticulate brachiopod.

Thanks much.

[FossilNerd]

Thanks for posting this! I’ve never searched through micro matrix, but this thread has intrigued me. So much to be found, and so much that I’m missing out on. 

[Nimravis]

3 minutes ago, FossilNerd said:

Thanks for posting this! I’ve never searched through micro matrix, but this thread has intrigued me. So much to be found, and so much that I’m missing out on. 

Glad you are enjoying it, I will be posting more as time goes on.

[Monica]

Great stuff, Ralph! 

 

I, too, can vouch for the vast number of fossils found in Doren's micromatrix - he sent me a cup of the stuff, and as soon as it arrived I poured about a tablespoon onto my hand just to have a quick peek, and I think I found about 20 fossils in it!!!  I've selected my favourite items from the micromatrix and placed them into a floating membrane display, and then I put the rest back in the bottle so that my kids can search it - Viola has been interested in fossils for a number of years now (although reading novels is taking up most of her free time these days), but the cool thing is that the micromatrix has piqued William's interest and he now says he likes fossil shark teeth, too - woohoo!!! 

 

Thanks for the interesting read, Ralph @Nimravis!  And thanks again for the micromatrix, Doren @caldigger!

[MarcoSr]

11 hours ago, Nimravis said:

Marco to be honest with you, not much falls to the bottom of the bucket, once I finish searching the finest matrix, I will have a lot more to post.

 

16 hours ago, caldigger said:

I may add, the matrix went through 6 wash cycles before I even sent it to him.

A 24-36 hour initial soak in a bucket, then 4 separate hot water wash cycles before it goes into a 24 hour Hydrogen Peroxide soak, it gets rerinsed. Then thoroughly air dried for close to a week before it is packaged up.

It is unfortunately a quite lengthy and messy cleaning process with a low yield amount ( 5 gallons of raw sifted matrix whittles down to about 1/2 gallon) when finished.

But it is a high yield fossil wise matrix.

 

 

Doren does a really good job of washing the matrix down.  Most of the really small stuff gets washed out in that process unless you use a 1/50" (.02")/ .5 mm sieve in the process.

 

Most of the teeth in the below picture look like Mobula versus Mustelus.

 

 

 

For comparison:

 

Mobula:

 

 

 

 

Mustelus:

 

 

 

 

Marco Sr.

 

[Nimravis]

54 minutes ago, MarcoSr said:

Most of the teeth in the below picture look like Mobula versus Mustelus.

Thanks Marco for the ID help, the pieces will just get a lot smaller in Tray 4, hopefully I can see them for better ID's.

[Tidgy's Dad]

15 hours ago, Nimravis said:

Here you go- it is concave and wafer thin.

 

Yes, Novocrania, I believe, the nomem novum proposed for Neocrania which is a name occupied by an insect. 

That's a beauty, Ralph. 

[Mark Kmiecik]

Thanks for the micro-tour  Ralph. As usual, your organized presentation and excellent photos have made it a pleasure. Looking forward to seeing the rest.

[Nimravis]

2 hours ago, Mark Kmiecik said:

Thanks for the micro-tour  Ralph. As usual, your organized presentation and excellent photos have made it a pleasure. Looking forward to seeing the rest.

Thanks Mark, appreciate the comments.