Are these holes natural or drilled?

[mn9000]

I picked up an interesting looking rock at the creek today with 2 holes in it, I didn't think much of it until I started looking a little closer and noticed what appeared to be score marks on the inside of each hole.
Can anyone tell from the photos if the holes are natural or man made?

If they are man made, why would they choose such an odd shaped rock to drill 2 holes in?

SW Missouri find

 

[Obsessive]

one vote natural!

cool rock. I probably would have picked that up too.

 

[Charl]

I see what you mean. In the first two photos, seemed natural for certain. Until I saw the closeups, and they sure do looked drilled in the closeups, so I see where you're coming from. Was not expecting that at all....

 

[Tpmetal]

Yeah looks natural until the closeups... maybe they are result of fossil ?

 

[bill_wabo]

Looks drilled.

 

[creekhunter]

It does look drilled...but why!

 

[wisconsinwalter]

Caused rocks swirl creating the holes in the weaker material


Sent from my iPhone using Tapatalk

 

[Charl]

Yeah looks natural until the closeups... maybe they are result of fossil ?

I came back to the thread because crinoid column came to mind, but the grooves on the outside of such fossil columns are not tightly packed, like what we see here. Really doesn't match. What we see is what we expect to see as a result of drilling, except the exit holes seen in the first two photos. Maybe a fossil we haven't thought of yet, but sure looks like drilling.

 

[The Grim Reaper]

It does look like drilling, but you have to ask yourself why. Why would such a rock have been drilled? What was it's function? I'd be willing to bet it is some type of natural erosion and possibly from a Fossil. That is a tough one to call though.

 

[scepter1]

Drilled by rock-boring mollusc's like Piddocks or some other related species.

 

[CASPER-2]

because only have the pic to go on - material looks like fossilized bone - tough when not able to view in hand

 

[Charl]

Drilled by rock-boring mollusc's like Piddocks or some other related species.

This is a suggestion I would like to explore further. If you can post photos of such examples, that would be good to see.

 

[fishstick]

Practice piece maybe?

 

[The Grim Reaper]

Drilled by rock-boring mollusc's like Piddocks or some other related species.

Very interesting theory. Here's some info on that possibility.

https://the-hazel-tree.com/2013/08/21/piddocks-anything-but-boring/

 

[monsterrack]

JMO it's from a type of Crinoid fossil, there are many. It would have to be a cane/reed drilled hole to not have a taper and like Steve said why go to that much trouble for such an off shape stone. I may be wrong but if it was from a Mollusc's type creature, I think it would be a smooth bore hole like the ones in the photos Steve posted of their holes.

 

[gentleone444]

Very cool piece either way. Very interesting what nature does.

Sent from my LG-H872 using Tapatalk