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[Foothill Amblers]

Hi, Please see the attached pdf file. I found this large fossilized bone in a creek bed in California.  Based on photos found online, it appears to be an astragalus.  It has a distinct rectangular quartz inclusion that may have filled a preexisting cavity.  I'm curious whether that is a distinctive trait that might allow it to be identified.  Again, scanning the web, it may be a sloth or hippo, but I have no idea whether they corresponded in size.

 

Being new to fossilling, I'm not at all sure of its origins.  I originally thought it was a dino bone and am open to all opinions! THANKS!

 

 

 

 

 

 

FossilFind2022.pdf

[DPS Ammonite]

2 hours ago, Foothill Amblers said:

Hi, Please see the attached pdf file. I found this large fossilized bone in a creek bed in California.  Based on photos found online, it appears to be an astragalus.  It has a distinct rectangular quartz inclusion that may have filled a preexisting cavity.  I'm curious whether that is a distinctive trait that might allow it to be identified.  Again, scanning the web, it may be a sloth or hippo, but I have no idea whether they corresponded in size.

 

Being new to fossilling, I'm not at all sure of its origins.  I originally thought it was a dino bone and am open to all opinions! THANKS!

 

 

FossilFind2022.pdf 939.85 kB · 7 downloads

Welcome to the Forum. What part of Northern California did you find it in? What part are you from?

 

Looks like part of a Native American stone hammer or similar created from an igneous rock. Searched for “Native American hammer stone”: see screen shot.

 

Screen shot of part of your images at bottom.

 

 

Edited December 7, 2022 by DPS Ammonite

[Randyw]

I’m with dps on this one. Thats a typical groove attachment point for a native american piece. Looking at picture 4 i suspect axe but it’s too broken to be sure…

[JohnJ]

It is missing too many characteristics to be a bone.  

 

Although very suggestively shaped, I disagree that it is a stone ax.  The groove is too irregular and the unbalanced symmetry undermines the intended purpose.  I see a differentially weathered stone.

[Mark Kmiecik]

Hammerstone came to my mind immediately. I agree with the others. Very nice find!!!

[Randyw]

2 hours ago, JohnJ said:

and the unbalanced symmetry undermines the intended purpose

I believe it is missing pieces from both front and rear. Basically its just the center attachment point… as to the irregular groove I seen authenticated stone tools with the same irregularity. My wifes family are native american and my brother in law used to make stone tools as a hobby before he died. So I got interested in them and used to check out displays. As always i could be mistaken and eagerly await further replies!

[JohnJ]

2 hours ago, Randyw said:

I believe it is missing pieces from both front and rear. Basically its just the center attachment point… as to the irregular groove I seen authenticated stone tools with the same irregularity. My wifes family are native american and my brother in law used to make stone tools as a hobby before he died. So I got interested in them and used to check out displays. As always i could be mistaken and eagerly await further replies!

 

With respect to your experience, I agree the rock is broken on the surfaces shown in photos 3 and 4.  But, those views also show just how unsymmetrical and poorly balanced it would be as a portion of a stone ax.  Further, the groove doesn't exhibit evidence of pecking and grinding from human alteration.

[Randyw]

Roflmao! I knew we had to disagree sooner or later! 

[Foothill Amblers]

This is fun!  Thanks all for the quick responses.  I very much appreciate your input, which completely changed my suspicions as to its identity..  As a complete novice (it really shows here :)) I agree that it must be a hammer stone as shown in figs 5 & 6.  I originally discounted the obvious due to its size.  I had noticed photos of hammer stones online but could not find pictures of a hammer stone this big.  After more research, it appears to b a grindstone used to process food., It weighs over 13lbs now.   I can imagine it with a handle lashed on so that it could be rotated to crush acorns.

 

I appreciate all of your insights & opinions.

[JohnJ]

@Foothill Amblers 

Can you take better focused, close-up photos of the stone texture in the 'groove'?  

[Foothill Amblers]

Here are closeups.  Best I could do with my iphone.  What do you think?

[JohnJ]

From what I can see, I still think it is a natural feature.  The abrasive stones or other tools used to make the grooves in a stone ax typically create a uniform radius.  This one is not very uniform and has deeper, smooth pits that bolster a natural occurrence.  

 

It takes a lot of effort to create a grooved stone ax.  As I've said, the asymmetry of this piece 'begs the question' of why choose to put all that effort into this rock vs a more well balanced stone?

[Foothill Amblers]

Thanks!  That pretty much the mystery.  I appreciated your advice and that of the others.  Have a good day!

[DPS Ammonite]

I agree with John that this is rather crude to be a well-balanced hammer. The concave groove around the whole rock still looks man made. I see no evidence that there is softer layer that was preferentially eroded. I see no lineations of the holes or inclusions in the rock, or bedding parallel to the groove. I see a hard rock that was broken and polished in a stream.
 

Groove really looks man made, but for what purpose? Could it have been a counterbalance? Could this have been a weight that was used with a rope or cable. I have seen rocks used by ranches with crude grooves that anchored guy wires for fences. 

[Foothill Amblers]

Thank you all!  The consensus is that I found a nicely polished river rock. I'll likely put it back.