Brazos River Skull Chunk

[GPayton]

Found this strange little chunk of bone about two weeks ago on the Brazos and have had zero luck trying to identify it on my own. Nothing seems like an exact match. The complex series of holes and tube-like structures on the one side makes me think ear bone, and the suture markings lining the edges of the bone on the back side make me think skull fragment. Similarly, the thin raised area makes me think zygomatic process. My best guess would be something like the temporal bone on the back of a bison or horse skull, but I haven't been able to find much to make me sure of that ID. @Harry Pristis - do you have any ideas or helpful diagrams? 

 

[Harry Pristis]

I'm sorry that I can't help identify this periotic.  @Shellseekeris fond of these fossils.

[Shellseeker]

2 hours ago, GPayton said:

My best guess would be something like the temporal bone on the back of a bison or horse skull, but I haven't been able to find much to make me sure of that ID. @Harry Pristis - do you have any ideas or helpful diagrams? 

Thanks, Harry. This is an earbone... 3 Inches !!!! Horse or Bison are not BIG enough to have this earbone and it is not marine mammal.

I would be thinking Mammoth, Mastodon, or Giant Sloth.... Here are some examples of the 1st two...

 

[Brandy Cole]

I was thinking it resembled the mammoth's ear bone I found a while back.  Especially your third picture.  But it looks a lot flatter to me than what I found. Mine seems more elongated.

 

It's an awesome find. To me it looks more like the mastodon examples from @Shellseeker.  Either way, really cool.

Edited April 20, 2022 by Brandy Cole
For clarity

[GPayton]

31 minutes ago, Shellseeker said:

Thanks, Harry. This is an earbone... 3 Inches !!!! Horse or Bison are not BIG enough to have this earbone and it is not marine mammal.

I would be thinking Mammoth, Mastodon, or Giant Sloth.... Here are some examples of the 1st two...

 

Thanks for linking that thread! Would you say that the entire bone I've found is an earbone or just the smaller bumpy section that seems to be connected to the larger mass and that's separated by that small gap that you can see in the third picture? To me at least the skull suture marks indicate that the bone was attached to the skull as part of the skull itself - are periotic bones sutured to the skull or just loosely attached to it? 

[Mahnmut]

Hi GPayton,

in most land mammals they are sutured to the skull, in whales they are only loosely attached to accommodate underwater hearing.

In your third pic I think I see the suture line running all around it.

Best Regards,

J

Edited April 20, 2022 by Mahnmut
additional info

[GPayton]

On 4/20/2022 at 3:55 AM, Mahnmut said:

Hi GPayton,

in most land mammals they are sutured to the skull, in whales they are only loosely attached to accommodate underwater hearing.

In your third pic I think I see the suture line running all around it.

Best Regards,

J

Sorry, @Mahnmut, I see what you're talking about when you're talking about the suture line running around the earbone itself, but I was referring to the raised striations running along the outside of the entire chunk of bone. As far as I understand it, the periotic would be the small bumpy nodule at the center of the skull chunk with the hole in it, but what bone would that mean it's sutured to? The temporal bone?

[Mahnmut]

Hi again,

I was referring to the same structure along the outside. Yes, would be the temporal then. I think what is called the periotic here could also be called the pars petrosa ossis temporalis, at least  in human anatomy (I can not guarantee for paleontological terminology). The aforementioned whale bones (cetoliths) are apparently a fusion of pars petrosa and tympanicum, separate from the temporalis unlike in your find.

Below is how I interpret your find, the round opening visible in your second to last pic should be on the left end of the blue part then, leading to the outer ear.

One of the most complex pieces of bone one can find. With some luck you can find the auditory ossicles inside.

 

Best regards,

J