Is this a tooth or tusk?

[HMBfossils]

Hi - Does anyone know what this is?  It's smooth and heavy like rock.  Thanks!

[jikohr]

I think it's just a rock. A very pretty rock, but not a fossil.

[HMBfossils]

Thanks but it's def not just a rock.  It's super weird.  Appreciate the input!

[Rockwood]

It doesn't look like a tooth of any kind to me. The photos of the ends seem to be out of focus. A better look at them might help. 

[HMBfossils]

Thanks for your reply! Here are some additional pics.  

[HMBfossils]

One more.

[Rockwood]

Much better. I think this probably is a tusk of some sort. Just a guess, but I wonder if it could be from something like a walrus. 

[Shellseeker]

This is the photo you want to show,  then no one will mistake it for a rock.... Likely Walrus

[jikohr]

I stand corrected!

 

Congrats!

[HMBfossils]

Thanks all.  Do you  think it's a fossil though?  We don't have walruses in California unless you're at the zoo...

[jikohr]

52 minutes ago, HMBfossils said:

Thanks all.  Do you  think it's a fossil though?  We don't have walruses in California unless you're at the zoo...

Where did you find it exactly? I'm assuming California, but besides that was it at the beach, a creek, in the mountains, etc.?

Locality gives a lot of information.

[Shellseeker]

You may not have Walrus now,  but

https://news.fullerton.edu/2020/11/paleontologists-uncover-three-species-of-extinct-walruses-in-orange-county/

[HMBfossils]

Guys, I think we literally have a bone yard off my beach in Half Moon Bay, CA (not a state beach).  So far you guys have identified my mammoth leg, prehistoric horse teeth, and now this tusk in like 2 months (not to mention all the shell fossils from the purrisma foundation which you can see in the surf where I found the bones).   I know the recent atmospheric rivers and crazy tides have washed a lot of stuff down.  A few people i know have found skulls and other stuff.  I just go out every day with my dog looking for sea glass but keep tripping over bones.  Would love to show any of y'all where I find them and participate in any excavations!!!  My sea glass friends and I would really enjoy the experience showing our sites to experts and learning from you....

 

[HMBfossils]

It was found high tide line at the base of the purissima formation near a cliff where I found the prehistoric horse teeth in the cliff itself.  No nearby creeks.

[JohnJ]

1 hour ago, jikohr said:

Where did you find it exactly? I'm assuming California, but besides that was it at the beach, a creek, in the mountains, etc.?

Locality gives a lot of information.

 

27 minutes ago, HMBfossils said:

Guys, I think we literally have a bone yard off my beach in Half Moon Bay, CA (not a state beach).  So far you guys have identified my mammoth leg, prehistoric horse teeth, and now this tusk in like 2 months (not to mention all the shell fossils from the purrisma foundation which you can see in the surf where I found the bones).   I know the recent atmospheric rivers and crazy tides have washed a lot of stuff down.  A few people i know have found skulls and other stuff.  I just go out every day with my dog looking for sea glass but keep tripping over bones.  Would love to show any of y'all where I find them and participate in any excavations!!!  My sea glass friends and I would really enjoy the experience showing our sites to experts and learning from you....

 

 

For future reference, "exact" locations are not really needed.  We usually do pretty well with regional proximity.  San Mateo County would probably be specific enough.   

[DPS Ammonite]

As Samantha used to say: "Calling Dr. Boessenecker, calling Dr.Boessenecker. Emergency! Come right away!" @Boesse

[Mahnmut]

Hi,

at first I thought fragmetn of walrus tusk, but one thing makes me wonder: 

in the closeup-cross section pic it looks as if the section was quite narrow to begin with, not circular as I would expect of a modern walrus tusk. Interesting piece of tooth/tusk in my eyes.

Sounds like an interesting place.

Best Regards,

J

[Rockwood]

2 hours ago, Mahnmut said:

at first I thought fragmetn of walrus tusk, but one thing makes me wonder: 

in the closeup-cross section pic it looks as if the section was quite narrow to begin with, not circular as I would expect of a modern walrus tusk

I think erosion has masked the amount of material that has been broken away. It may have lost a fair sized flake. 

[Shellseeker]

Might want to read this post... some similarities..

 

[Mahnmut]

Thats the part of the cross-section that makes me think this tooth was not zylindrical like a walrus tooth to begin with...

[Rockwood]

But this looks broken to me.

[Mahnmut]

1 hour ago, Rockwood said:

But this looks broken to me.

 

Agreed, I just say that I think the cross-section looks as if it was rather oblong even before it broke. Thus the thread linked by Shellseeker looks like a hot lead to me. My bet is on sirenian rather than walrus, dont know about other fossil pinnipeds, or something else even more exotic,  like beaked whale(?), but I do not think so. Just speculating about an eroded fragment.

Best Regards as always

J

[Rockwood]

On 4/28/2023 at 2:32 AM, Mahnmut said:

Hi,

at first I thought fragmetn of walrus tusk, but one thing makes me wonder: 

in the closeup-cross section pic it looks as if the section was quite narrow to begin with, not circular as I would expect of a modern walrus tusk. Interesting piece of tooth/tusk in my eyes.

Sounds like an interesting place.

Best Regards,

J

I just found some time to look into the circular section concept. My photos from the Maine state museum, along with a number of photos online seem to show a considerable amount of variation from circular aspect. Some look down right convoluted at the proximal end. I seriously doubt that this could from a dugong. The texture looks quite different to me.

[Boesse]

Hey all,

 

Some of the finds being made recently with all this rain are late Pleistocene in age, for example someone else found a mammoth astragalus back in December or January. This specimen is not from the Purisima Formation: bones and teeth from that unit are generally dark brown or black, and in Half Moon Bay, do not weather out 1) cleanly from the matrix or 2) in complete pieces, owing to extensive fracturing. I think it is fair to assume this specimen is from late Pleistocene deposits.

 

Sirenian: only the earliest known sirenians from the west coast retained tusks, and there's just a handful of them - Dioplotherium allisoni, which is early or middle Miocene.

 

As for walrus: it's too narrow from side to side, it seems.

 

I'm not sure what this thing is.