My first Acquired Micro Matrix Hunt- Aguja FM, Cretaceous, Texas

[Troodon]

Have you seen this post

 

 

[Miocene_Mason]

21 minutes ago, Troodon said:

It all comes from the source in Texas.  The Mich seller is probably buying from him

@MicroTooth Hello! my thoughts are the same as Franks, it probably came from him originally (I think he leases the ranch’s fossil quarry/outcrop). I got the smaller size and he hasn’t put it back up yet. I think he will in the future though, might have to be patient. It was one 3/4 full gallon bag for me, mixed chunks and finer stuff. I will definitely keep posting, it waiting for my sieves to arrive in my mailbox, should be here by Friday. I’ll test them with some Purse Matrix, then I’ll try it will the Aguja stuff.

 

@Troodon thanks for the extra examples! I have found one more complete. Fish vert and a few broken ones, they all look very similar. And I missed that topic so thanks for sharing that, as luck would have it I found one of those teeth as well (the Amiid) and was wondering what it was. Good thing you posted that because I was thinking some sort of carpet shark! Do you know if 1/20” mesh will catch all or most of these little ones? Thanks for all your help! It is much appreciated!

@digit Sieve sets on its way here! Thanks for the tip off!

[Troodon]

I know the Sieve set bought one at Tucson show but gave it to a friend of mine.  What's the opening in a 1/20 mesh.  Lots around 2mm but there is quite a few less than 1mm

[Miocene_Mason]

1 hour ago, Troodon said:

I know the Sieve set bought one at Tucson show but gave it to a friend of mine.  What's the opening in a 1/20 mesh.  Lots around 2mm but there is quite a few less than 1mm

It’s 1.27 MM. That’s irritating. I’ll be doing it over a bucket, drying, and keeping it’s contents anyway. Thanks!

[Troodon]

6 hours ago, WhodamanHD said:

It’s 1.27 MM. That’s irritating. I’ll be doing it over a bucket, drying, and keeping it’s contents anyway. Thanks!

You will get most of them 

Here is an example of a 1 mm shark tooth.  

 

Just take a look at the scale bar for adult teeth small to say the least.   Juvies may not make it.  Man they are small...

 

[MicroTooth]

9 hours ago, WhodamanHD said:

@MicroTooth Hello! my thoughts are the same as Franks, it probably came from him originally (I think he leases the ranch’s fossil quarry/outcrop). I got the smaller size and he hasn’t put it back up yet. I think he will in the future though, might have to be patient. It was one 3/4 full gallon bag for me, mixed chunks and finer stuff. I will definitely keep posting, it waiting for my sieves to arrive in my mailbox, should be here by Friday. I’ll test them with some Purse Matrix, then I’ll try it will the Aguja stuff.

 

@Troodon thanks for the extra examples! I have found one more complete. Fish vert and a few broken ones, they all look very similar. And I missed that topic so thanks for sharing that, as luck would have it I found one of those teeth as well (the Amiid) and was wondering what it was. Good thing you posted that because I was thinking some sort of carpet shark! Do you know if 1/20” mesh will catch all or most of these little ones? Thanks for all your help! It is much appreciated!

@digit Sieve sets on its way here! Thanks for the tip off!

@WhodamanHD Thanks for the additional information and good luck with your new sieve set when it arrives.  Those will also give you a whole different angle to check out what Brownies and Purse have to offer.

 

@Troodon Thanks as well. I may just have to splurge and pick up the medium flat rate box if the smaller ones don't show up as options again. 

[Miocene_Mason]

3 hours ago, Troodon said:

Just take a look at the scale bar for adult teeth small to say the least.   Juvies may not make it.  Man they are small...

That’s ridiculously small!! I don’t know how I’m gonna find those.

[Miocene_Mason]

1 hour ago, MicroTooth said:

@WhodamanHD Thanks for the additional information and good luck with your new sieve set when it arrives.  Those will also give you a whole different angle to check out what Brownies and Purse have to offer.

 

@Troodon Thanks as well. I may just have to splurge and pick up the medium flat rate box if the smaller ones don't show up as options again. 

Thanks @MicroTooth, I’ve micro hunted with bother before but it was not easy, now it should be much nicer. What sites do you do micro at?

[Troodon]

1 hour ago, WhodamanHD said:

That’s ridiculously small!! I don’t know how I’m gonna find those.

Carefully very carefully 

 

[Miocene_Mason]

54 minutes ago, Troodon said:

Carefully very carefully 

 

[MicroTooth]

12 hours ago, WhodamanHD said:

Thanks @MicroTooth, I’ve micro hunted with bother before but it was not easy, now it should be much nicer. What sites do you do micro at?

I'll send you a PM. 

[ynot]

12 hours ago, WhodamanHD said:

That’s ridiculously small!! I don’t know how I’m gonna find those.

 

11 hours ago, Troodon said:

Carefully very carefully 

Magnification helps too.

I use a jewelers headset.

[Miocene_Mason]

34 minutes ago, ynot said:

I use a jewelers headset.

I have one that’s kinda like that somewhere, need to find it. Still, that’s just not fair!

[ynot]

6 minutes ago, WhodamanHD said:

. Still, that’s just not fair!

Yes it is too fair!

 

My headset cost around 120$ 15 years ago. Has its own carrying case and 6 different levels of interchangeable lenses.

[Troodon]

Bowie, MD was a good site to hunt for Cretaceous microfossils.  Lots of work but the finds could be seen using a jeweler headset it worked.   The Aguja mix has a lot more DOT fossils which just makes it that much harder to see.  Just need to go slow.

[Miocene_Mason]

On 7/17/2018 at 7:24 AM, Troodon said:

Bowie, MD was a good site to hunt for Cretaceous microfossils.  Lots of work but the finds could be seen using a jeweler headset it worked.   The Aguja mix has a lot more DOT fossils which just makes it that much harder to see.  Just need to go slow.

Somehow I missed this post! I have heard about the Bowie site, but I have also heard they now have an aversion to fossil hunters (probably because someone did something stupid) soooo that ones off the list. The site I’m going to is terrestrial, but I think there is at least a possibility of bone or teeth being preserved. It’s in the Potomac group, I can’t tell which formation but it is rich in wood and is primarily clay so I think it could be the Arundel Clay. 

[Miocene_Mason]

Found this in the Aguja matrix. What “this” is, I got no clue. It seems to be enamel or bone. I haven’t measured but probably a bit over a MM

[Troodon]

Is it a chard of a tooth?

[MarcoSr]

On 7/15/2018 at 11:00 PM, WhodamanHD said:

 

 Do you know if 1/20” mesh will catch all or most of these little ones? Thanks for all your help! It is much appreciated!

 

 

I search lots of matrix from sites all over the world from different time periods.  Cretaceous matrix especially has a very high concentration of very small vertebrate fossils. .4 mm mesh size catches almost all of the Cretaceous species of shark and ray teeth.  However there are a couple of species of shark and ray teeth that can fall through .4 mm.  Some fish teeth can also fall through .4 mm.  If you are also interested in shark and ray placoid scales, a lot of them can fall through .4 mm.  .2 mm pretty well catches all of the vertebrate stuff.

 

For .4 mm I use the following sieve over a 5 gallon bucket when washing:

 

https://www.bayteccontainers.com/5-gallon-400-micron-ez-strainer-insert-for-pails---drums.html#gsc.tab=0

 

Marco Sr.

[digit]

Nice! Now I'll have to get some Cretaceous micro-matrix just so I can buy one of those 400 micron strainers.

 

Cheers.

 

-Ken

[Miocene_Mason]

58 minutes ago, Troodon said:

Is it a chard of a tooth?

I assume, perhaps some sort of herbivore? Mammal or dinosaur I guess.

[Miocene_Mason]

45 minutes ago, MarcoSr said:

 

I search lots of matrix from sites all over the world from different time periods.  Cretaceous matrix especially has a very high concentration of very small vertebrate fossils. .4 mm mesh size catches almost all of the Cretaceous species of shark and ray teeth.  However there are a couple of species of shark and ray teeth that can fall through .4 mm.  Some fish teeth can also fall through .4 mm.  If you are also interested in shark and ray placoid scales, a lot of them can fall through .4 mm.  .2 mm pretty well catches all of the vertebrate stuff.

 

For .4 mm I use the following sieve over a 5 gallon bucket when washing:

 

https://www.bayteccontainers.com/5-gallon-400-micron-ez-strainer-insert-for-pails---drums.html#gsc.tab=0

 

Marco Sr.

Thanks for the advice and the link! I have quickly discovered my smallest sieve size is nowhere near small enough. That’s pretty cheap for a sieve (though the shipping triples it) so I probably will get that and sieve through the smallest stuff. Thanks!

[MarcoSr]

1 hour ago, WhodamanHD said:

That’s pretty cheap for a sieve (though the shipping triples it) so I probably will get that and sieve through the smallest stuff. Thanks!

 

I also bought some .6 mm sieves when I bought my .4 mm sieves to lower my per sieve cost with combined shipping.  A lot of faunas don't have vertebrate specimens down to .4 mm and the larger mesh size of .6 mm makes it easier to wash the matrix and you don't get really fine matrix residue that really doesn't have vertebrate fossils in it and which takes extra time to search.  So depending on the matrix, I can use .2 mm (I rarely use this because looking for .2 mm specimens requires use of a microscope which for me is very tedious and frankly quite boring), .4 mm, and .6 mm sieves, and window screen (which is usually 1.5 to 1.75 mm) to wash my matrix in at home.

 

Marco Sr.

[MarcoSr]

After seeing this post, I purchased a small flat rate box of this Cretaceous, Campanian, Aguja Formation matrix from e-bay.  I received about 2/3 of a gallon of unprocessed matrix.  The matrix was extremely easy to break down.  I soaked the matrix in water overnight and then washed it in a .4 mm sieve.  I got about one cup of residue to search.  Most of the matrix residue and specimens were fairly small sized (.4 mm to 2 mm) and would have fallen through window screen.  So this matrix required magnification and experience to search properly.  I used my desk top loupe magnifier instead of one of my microscopes to search the matrix.  Using a microscope to search matrix is just too time consuming and tedious for me.

 

I didn’t find many larger specimens that were recognizable.  The few larger specimens were mostly bone fragments although I did find a gar scale and a serrated edge portion of a Theropod tooth.  Luckily my interest is micro vertebrate specimens or I would have been very disappointed in this matrix.  Below is a gem jar (1.75 inch diameter) with the nicer specimens that I found in this matrix.  I haven’t really looked closely yet at everything to id it but roughly what follows is what I found.  There were a good number of bony fish teeth and that gar scale.  A number of shark teeth from a couple of genera like Lissodus and Restesia aka Squatirhina.  A single ray dermal denticle.  A number of sawfish oral teeth and at least one rostral tooth from genera like Ptychotrygon, Ischyrhiza and Onchopristis.  Four reptile teeth probably from something like Brachychampsa.  There was a partial frog humerus and very small frog jaw fragment.  A couple of recognizable mammal bones (there were a good number of small bones but the vast majority were not recognizable by me).

 

 

Marco Sr.

[digit]

Interesting stuff. I like picking micro-matrix but that stuff may be too micro for my tastes.

 

Cheers.

 

-Ken