I think this is a mammoth fragment

[Jim Kovalchick]

I found this at Myrtle Beach. It looks to me like a worn mammoth tooth fragment, but I'm interested in opinions of others.

 

The rock is very dense, and where it is chipped it has strips of varying light and dark colors.  It is a little larger than a baseball.

 

I assume that much of the wear is from rolling in the surf.

 

I will post other views in replies.

 

Thanks,

Jim Kovalchick

[Jim Kovalchick]

[Jim Kovalchick]

[Jim Kovalchick]

[digit]

Nope. But really convincing from some angles. The last image made me scroll back to the top and review them all again.

 

I didn't have a scale looking at the first image and considered a pufferfish tooth plate initially as a possibility (they have stacked plates in back of their row of teeth used to crush invertebrates). The size (using your hand for scale dropped that from consideration as it is way too large for that). My guess is some sort of alternately layered sedimentary rock.

 

Mammoth teeth are composed of elongated rings of hard shiny enamel. These rings are filled with and connected together with cementum material. The labial and lingual (outer and inner) surfaces have a ridged texture (not unlike your last image) but I believe your texturing is just due to differential weathering of softer and harder layers. Here are some of the chunks I've found over the years in the Peace River:

 

 

 

Here's an image of a tooth where you can see the lighter colored rings of enamel and get a good look at how the softer cementum cements these together (they don't call it "cementum" for nothing). Your rock seems to show fine parallel structure that is more indicative of the layers laid down of a sedimentary rock. The texture in the image showing the fractured surface (second to the end) shows this layering very well. This type of layering is never found in a mammoth tooth as they do not grow that way. Additionally, the conchoidal (shell-shaped) fracture in this photo indicates that the darker material is very hard and glassy (likely high in silica). Fossils too can be mineralized with silica but the layering indicates some sort of geological cherty material.

 

Cool looking rock--I'd certainly have picked it up and taken it home. Not a fossil but a great mammoth tooth "faker" for the display cabinet nonetheless. Would also likely look good polished in a rock tumbler.

 

 

Cheers.

 

-Ken

 

 

 

 

 

[Jim Kovalchick]

Ken,

Thanks for the detailed response. I am still inclined to believe that there is a fossil origin to my rock, but some of your observations mimic my own doubts on mammoth and why I posted in first place. 

Yes, the big chip on the one side shows very little cleavage or differentiation in texture. The latter characteristic tends to eliminate mammoth tooth. 

The reasons that I am still think fossil origin are as follows.

The ridge bands are regular in width. Each band is made up of finer layers, and the surface is shiny unlike sedimentary rock layers that tend to be dull with cleavage at the layers. Between the layers there is a reddish brown color material.  The rock must have been subject to heat and pressure to agatize it after the ridges formed. The rock reminds me very much of a large whale bullad on the same beach. One of the sides that does not have ridges is ground down obliquely to the ridges much like an ejected pachyderm tooth. 

 

 

 

[digit]

The wedge shape is very characteristic of proboscidean teeth but not exclusively so. The regular banding is also found on these teeth but not quite in the same way as shown on your object. I can not think of any other large fossil object with banding like that. Repeated layering is quite often a sign of geological features and that is what I think it is likely to be.

 

 

Cheers.

 

-Ken

[Jim Kovalchick]

Thanks Ken. I appreciate your response.

 

Jim K

[darrow]

Though very suggestive at first glance, it is not a fragment of mammoth tooth. 

 

It looks like a piece of foliated metamorphic rock like gneiss.  Perhaps from offshore when USACE replenished the beach last year.

https://www.myrtlebeachonline.com/news/local/article235477947.html

[darrow]

For comparison...  mammoth tooth fragments I've collected from dredge spoils beach areas on the Texas coast.