Mammoth or Mastodan Tusk?

[Billco]

Is the possibly a mammoth or mastodan tusk?

 

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[Kray Gelder]

Interesting. If it is a tusk, you should be able to scratch through the crust and find ivory.

 

[CaptEsteban]

Looks like it to me ! YEAH !

 

[Carolina Tom]

Show us a pic of the end face please.

Looks good.

 

[Billco]

I’ll get that later when I get back to it. Thanks

 

[Perico]

Looks like a rib section. Need to see the broken ends. Post pics please.

 

[ToddsPoint]

Mammoth ivory has fine criss-cross lines when polished and viewed from the end. These are called Schrager lines. Gary

 

[GoDeep]

Possibly a petrified mondo duke...

 

[PaleoCris]

This appears to be a Sirenian rib. Most likely dugong.

 

[diggummup]

Looks more bone than ivory to me also.

 

[PaleoCris]

The holes in this rib section is the result of boring clams (Pholadidea). Their bore holes are very commonly found on dugong rib sections, but I have never seen them on ivory. You can differentiate the ribs of other marine mammals like porpoises and whales from dugongs due to the density of the bone, which helps weigh down the dugong, allowing it to dive rather than float constantly as it would if it's bones were not solid. The same goes for manatees.

Dugong bones are solid, often times have clam bore holes, and will have growth rings (more like a series of half circles) on the broken cross-section (but not the crosshatching seen in ivory).