Austin Texas Area Trilobite Find

[cds7189]

I found what appears to be a trilobite specimen in the Austin, Texas area. The fossil was found embedded in the bank of Brushy Creek in Round Rock, Texas that is in the region of Austin. I was told the specimen is unusual to this region and that no deposits in or around this area would support trilobite finds. Jess also told me that there may be people who would like to examine the fossil. I'm not sure how unusual the specimen is to this location but wanted to get some insight regarding this specimen. I'm not a professional and did use a week vinegar bath and a dreamel to remove most of the matrix. If anyone could direct me in the appropriate direction I would appreciate the help.

Edited January 15, 2015 by cds7189

[Herb]

Nice trilobite. I think someone left you a present. That looks Devonian. I may be wrong but I think Austin is in the middle of the Cretaceous stratas.

[piranha]

That trilobite is quite obviously a large Devonian phacopid from Morocco. Someone had a twisted sense of humor planting it there.

[Herb]

At least they left a good one.

[cds7189]

I'm certain this wasn't left as a present. It was in the wall of the sandstone creek bed and I used a chisel / hammer to remove it. I took it back to my home were I've been working to remove the matrix for the last 8 months or so. This was absolutely originated in the Round Rock, Texas area. I can even bring any one to the exact spot I removed the fossil and show the hole in the rock I removed it from. I'm sure the matrix left on the fossil compared to the location would verify what I'm saying.

Edited January 15, 2015 by cds7189

[Auspex]

This is very interesting!

What is the geologic possibility?

[cds7189]

There must be some confusion with the identity of this specimen if it's thought it can only come from Morocco. Could this really be so unusual that I should take it to the University of Texas of contact someone regarding its find? I can take better quality pictures if I need to and post them. I think I even have pictures of it in the wall in the creek bed and before I started removing the matrix.

[bone2stone]

The Brushy Creek near Round Rock Texas is smack in the middle of a Lower Cretaceous deposit.

The last of the Trilobites went extinct at the Permian.

Were there any other fossils other than this trilo?

Jess B.

Edited January 15, 2015 by bone2stone

[cds7189]

Yes there are other fossils at this location. I don't know the identity but I find ocean type fossils in the sandstone all the time. Please understand that this is a new hobby of mine and I'm sorry that I'm limited on the information I can give. I do take ALOT of pictures I can show if any one has the time to look.

[piranha]

On 1/14/2015 at 4:40 PM, cds7189 said:

...I can even bring any one to the exact spot I removed the fossil and show the hole in the rock I removed it from. I'm sure the matrix left on the fossil compared to the location would verify what I'm saying.

 

 

With the uncanny similarity to the Moroccan phacopids, I'm sorry that I misunderstood the initial description of "embedded in the bank". If however, you had to chisel it free from the matrix, that's a completely different story. The good news is Phacops sp. is recorded from the Devonian Stribling Formation of neighboring Blanco County, 5 miles east of Johnson City at the foot of a bluff on the south bank and in a reach of Pedernales River known as Honeycut Bend. Hopefully this info can be correlated with this extraordinary find.

 

Barnes, V.E., Cloud, P.E., & Warren, L.E. (1947)

Devonian rocks of central Texas.

Geological Society of America Bulletin, 58(2):125-140

 

 

 

[JohnJ]

The others are correct regarding the Round Rock area geology and "sandstone" is not part of the geology of Brushy Creek in Round Rock. So, this trilobite, or the rock it was found in, was somehow introduced to the creek by someone locally. Whether it was a prank of some kind, or it originated from a load of rocks brought in from farther out in West Texas, or someone's rock collection was 'lost' and became consolidated in a gravel deposit in the bank, is impossible to say. But, the bottom line is that this trilobite did not originate from the local geology. I have traversed the length of the creek in that area, so I am familiar with the local rocks.

That you found something so small is a credit to your observational skills. Send me a PM if you would like to discuss particular details of the area.

[cds7189]

Please understand what I may be calling sandstone may not be sandstone. As I said this is just a hobby of mine and I'm by far not an expert in paleontology but just a Nurse. You can believe as you want to believe but I assure you that brushy creek has areas that are obviously lined with layered like "stone" that was not brought in from some other location and the "matrix" still on this fossil is from the location I found it in. I'm telling you a FACT that this fossil did originate in Round Rock, Texas and was dug out of the layered rock wall in brushy creek. Please I'm not trying to be insulting in any way and only stating the facts I know to be true. I'm not really sure how unusual this is but If every thing I'm saying is true I'm sure you guys would want to take a look at what I have.

Edited January 15, 2015 by cds7189

[JohnJ]

Please understand what I may be calling sandstone may not be sandstone. As I said this is just a hobby of mine and I'm by far not an expert in paleontology but just a Nurse. You can believe as you want to believe but I assure you that brushy creek has areas that are obviously lined with layered like "stone" that was not brought in from some other location and the "matrix" still on this fossil is from the location I found it in. I'm telling you a FACT that this fossil did originate in Round Rock, Texas and was dug out of the layered rock wall in brushy creek. Please I'm not trying to be insulting in any way and only stating the facts I know to be true.

Yes, the creek does have a great deal of layered bedrock exposed, but all of it is Cretaceous aged strata. That determines what kind of fossils are naturally found there.

I do not doubt that you found it in creek, and you don't have to be an expert to find something cool, or understand local geology.

[Uncle Siphuncle]

Fossils have a way of getting out of context. For instance, when a buddy of mine was in the middle of his divorce , his wife threw his entire collection into a Texas lake, piece by piece. I wonder if anyone stumbled upon it during the current drought.

[Missourian]

With a trilobite of that quality, there may be at least fragments of others in the deposit.

Edited January 15, 2015 by Missourian

[Ptychodus04]

It could have been re-deposited. I've seen some reworked material in creek beds that was pretty hard and compressed. That's the only natural way a Paleozoic fossil ends up in a Mesozoic area.

[cds7189]

I agree with you all. All I can do is report what I've found and let the experts sort out the rest. I only posted it because the M.D. I work with told me I should show it to someone who knows. Is this really that big of a find? I knew it was some type of fossil and not part of the natural rock but didn't realize it was so unusual. You guys don't realize that I'm really not that lucky so this must be something of very little importance.

[Doug D.]

I would be doing backflips if I found a trilobite like that! Regardless of how this mystery turns out, you have a fine fossil!

[cds7189]

I'm glad I found it but still not sure how big of a find it is. Thanks for all or everyone's help.

[kauffy]

you mentioned you may have some pictures of the specimen in the matrix, or the "hole" that you dug it out of? I would find these most interesting...

Agreed it cannot originate from the cretaceous strata, that doesn't mean it hasn't been deposited by some sort of re-working over time or as others have stated simply another collectors misfortune/trickery!

A nice triolobite regardless!

Chris

[JohnJ]

There are no naturally occurring Paleozoic strata or rocks in this watershed.

[RyanNREMTP]

Interesting, I'll be following this one closely.

[Auspex]

Biggest. Puzzle. Ever.

The finder describes, convincingly, extraction of this specimen from consolidated strata. The skeptics include folks who are intimately familiar with the rocks of the area...

I discard the notion that this is a mesozoic trilobite, but am unable to discount the possibility that there is an isolated outcrop of time-appropriate rock where there 'shouldn't be any'.

Were I in the area, I would jump at the chance to see and assess the site!

[Carl]

The digging photos are critical at this point.

[cds7189]

I will post the pictures of the "hole"/location where I found the fossil when I get home. With the obvious re-deposited of the fossil is it possible it could have washed downstream and naturally deposited in soil that compressed over time? I don't see how it could be a prank if I had to retrieve it from the bank of the creek. I guess the soil/rock could have been brought in at one point in time. Only history knows. Just glad I found it and glad I have this site to help me understand.

Edited January 15, 2015 by cds7189