Circular indentations on fossilized dugong bone

[Mtwombly]

Hey guys, 

 

I have a special creek site close to me in South Florida. it yields marine fossils of every kind and even some artifacts. I have found many pieces of dugong bone with a strange circular indentation, and I’m really hoping someone can help me out with determining what causes this? I have found fossils of a huge variety of Pliocene/Miocene marine animals, and dugong bones are the only bones with such markings. There is a raised center and an almost perfect circular depression around it. 

[Rockwood]

I'd like to see this dry. It doesn't look like bone to me, but the texture is somewhat obscured.

[Mahnmut]

Hi,

if I didn t know better I would say they are shoggoth marks...

Sorry, no idea but courious to hear more.

Best Regards,

J

[pachy-pleuro-whatnot-odon]

Could they be limpet suction-marks, may be? Compare with the so-called "home scar" in the image below (source):

 

 

But I agree with @Rockwood that we should first establish this as bone at all... I'm not fully convinced either, although it does look a lot like it.

Edited December 17, 2021 by pachy-pleuro-whatnot-odon

[JohnJ]

To those of us that do not encounter dugong bone on a regular basis, its very dense characteristics can seem unlike what we normally expect in other mammal bone.

 

@Harry Pristis

[daves64]

Some sort of impact fracturing maybe? 

[Brett Breakin' Rocks]

15 hours ago, Mtwombly said:

There is a raised center and an almost perfect circular depression around it. 

My first thought (with these heavily eroded pieces) is that it might be weathering out differently based on the density of the bone laid down. They lay the bone down in 'rings' to act as ballast and some of those rings are thicker. Or my other thought is that we are looking at eroded infilled burrows since they are fairly uniform and don't have that more typical oval or flattened Dugong bone/rib shape ?

 

Cheers,

Brett