Hunting for ear bones/removing from extant skulls

[Plantguy]

Hey Gang, Happy New Year!

 

I'm not sure this is exactly a fossil prep question but it relates to Identifying an unknown supposed Pleistocene fossil from Iowa so here goes.

 

I'm trying to put together a comparative collection of extant/extinct mammal inner ear bones. I've got a number of fossil fragments from a number of critters and about to work on removing a couple of petrous bones/bulla (highlighted with red arrows) from a couple of extant skulls. Ive got to cut them out of 2 extant bovid skulls/cap--see photo below:

 

The smaller example on the left is from a sheep and the other a much larger bovid I'm assuming a cow/Bos. I am thinking I can take my dremel with a cutting bit and remove the sheep petrous bone fairly easily by removing a surrounding section thru the skull cap along the blue line i've drawn. The larger skull on the right is more stout so I'm looking for any easy/cheap ideas from Harbour freight, hacksaw ideas or other to cut the ear bones free. Perhaps the dremel will have no problem cutting thru it as well.

 

i've seen some pretty cool dissection equipment but I'm doing this on the cheap to satisfy the curiousity of how these bones are positioned/attached and identify their components and take some photos along the way. Any simple solutions for removal are welcomed. I'm ok with up/experimenting one side as I can always work on the opposite petrosal of each. 

 

 

Here's an unknown petrosal that I have that I want to compare against to compare the two extant bones too.

I was told it might be possibly bison from the Pleistocene of Iowa. That ID has not been confirmed

 

Thanks!

 

Regards, Chris 

 

 

[Shellseeker]

Chris,  Thanks for doing this !!!! I think that your unknown is marine mammal. I have seen it previously, just can not recall where... !!! Have you solicited @Boesse view point on it ? 

[Plantguy]

48 minutes ago, Shellseeker said:

Chris,  Thanks for doing this !!!! I think that your unknown is marine mammal. I have seen it previously, just can not recall where... !!! Have you solicited @Boesse view point on it ? 

Thanks Jack. 

Curiousity about what these things are and what they look like internally is a current sickness of mine. I had seen a reference or two on the web  about a pinniped. You made me look again and heres a very similar thread/here on the ff--if not the same unknown. 

The gal I bought this from says she got it from a local person and it came from Iowa and it was found near 10000 yr old bison bones...I was going 

down the land mammal ID path as I didnt think they had a marine mammal element out there. I hadnt asked Bobby but will do 

so now. @Boesse

 

I have a pretty beat up dugong fragment and will need to go find it but here are some pics, maybe Bobby has some additional thoughts about this newer unknown. 

He had referred me to Dr. Jorge Velez-Juarbe years ago who had said that it looked dugongid tentatively Nanosiren.  Its pretty fragmented so I'm not smart enough to make any comparison at this point to the newer unknown.  Maybe if I sectioned it....

 

Thanks again. 

 

 

[ClearLake]

5 hours ago, Plantguy said:

The larger skull on the right is more stout so I'm looking for any easy/cheap ideas from Harbour freight, hacksaw ideas or other to cut the ear bones free. Perhaps the dremel will have no problem cutting thru it as well.

 

i've seen some pretty cool dissection equipment but I'm doing this on the cheap to satisfy the curiousity of how these bones are positioned/attached and identify their components and take some photos along the way.

Your dremel with a cutting wheel should have no problem. A hacksaw, or really any fine toothed saw will also do the job. Keep in mind that if using high speed rotary equipment there is going to be that not so delightful aroma. They make a special bone saw, but you’re not performing surgery here, so go with what you have is my suggestion. 

[Plantguy]

On 1/7/2024 at 9:13 PM, ClearLake said:

Your dremel with a cutting wheel should have no problem. A hacksaw, or really any fine toothed saw will also do the job. Keep in mind that if using high speed rotary equipment there is going to be that not so delightful aroma. They make a special bone saw, but you’re not performing surgery here, so go with what you have is my suggestion. 

Thanks for the reply! Will let you know how it goes. 

Regards, Chris 

[Boesse]

Hey Chris! That's an easy one. That's a true seal petrosal/bulla - family Phocidae. I suspect it's from a harbor seal owing to its small size, but if originally from the west coast, it could potentially be from a juvenile elephant seal - or gray seal if from the northeast. I'm assuming it's from somewhere in the USA.

[Plantguy]

7 hours ago, Boesse said:

Hey Chris! That's an easy one. That's a true seal petrosal/bulla - family Phocidae. I suspect it's from a harbor seal owing to its small size, but if originally from the west coast, it could potentially be from a juvenile elephant seal - or gray seal if from the northeast. I'm assuming it's from somewhere in the USA.

Bobby, thanks for taking a look. Well I've been having fun with this one. As I was told initially it was bison (and several folks said it very well could be and also a few that said no) so I had not bothered you with an ID request as I was having fun with researching/comparing inner ear bones.  Hence this thread. 

 

Interestingly, or maybe not. the provenance I was given which I thought we had confirmed indicated this guy came Iowa and was it was found near bison bones and was thought to be bison and was approx 10000 yrs old. I'll go back to the seller to reconfirm that backstory....something is amiss!

 

Thanks again for the insight!

 

Regards, Chris  

 

 

[NickG]

I have a bunch of casts of NAm pinniped skulls. I'll try to get photos of those when they are unpacked if it would help. Have you look at this paper by O'Leary online?

 

https://www.biodiversitylibrary.org/bibliography/90242

 

O'Leary, M. A. (2010). An anatomical and phylogenetic study of the osteology of the petrosal of extant and extinct artiodactylans (Mammalia) and relatives. Bulletin of the American Museum of Natural History, (335). It's completely free to access here.

[ClearLake]

2 hours ago, NickG said:

Have you look at this paper by O'Leary online

Now there is a paper for the true ear bone lover!    Thanks!  I had to download that one even thought it is something I don't research too much, you never know!!

[Shellseeker]

1 hour ago, ClearLake said:

Now there is a paper for the true ear bone lover!    Thanks!  I had to download that one even thought it is something I don't research too much, you never know!!

Thanks !!! @NickG

I research ear bones a LOT !!! Hard to believe a paper this rich in detail and pictures has been around the last 15 years !!! @Balance

[Balance]

@NickG thank you. That’s a valuable resource!! 
 

I gotta keep going. @Shellseeker 

 

Think I’ve ruled out sus scrufa and bos taurus. 
 

I think we have the same bone. That much I can accept but I gotta keep looking. This is WAY above my pay grade for reading material so slow going. Very hard to orient the directions. I have trouble with that judging left to right let alone these 12D shapes. 
 

 

Jack’s is on left. 

 

[Shellseeker]

4 minutes ago, Balance said:

I gotta keep going. @Shellseeker 

 

Think I’ve ruled out sus scrufa and bos taurus. 

That is why this Research Paper is so important... Yesterday I do not know what the earbones for Sus scrufa and Bos taurus,  and today we can eliminate them for possibilities on earbones we find.  NOT all our fauna is in here but some (Whales/Dolphins, Equus, Deer,  etc ) ARE !!! This paper is pure gold in saving time to ID earbones... 

Here is Equus, with the PDF on the left and one of my finds on the right

[Plantguy]

8 hours ago, NickG said:

I have a bunch of casts of NAm pinniped skulls. I'll try to get photos of those when they are unpacked if it would help. Have you look at this paper by O'Leary online?

 

https://www.biodiversitylibrary.org/bibliography/90242

 

O'Leary, M. A. (2010). An anatomical and phylogenetic study of the osteology of the petrosal of extant and extinct artiodactylans (Mammalia) and relatives. Bulletin of the American Museum of Natural History, (335). It's completely free to access here.

Hey Nick, thanks for including the link!

 

I had seen her very helpful article awhile back and got the reference from one of Bobby's posts even further back. I mentioned it one of the threads somewhere. I have actually exchanged some info with her via email as well as a number of others at various universities about temporal bones/pertrosals/bullas.... These bones drive me a little nuts as very rarely do you find one in perfect condition that hasnt had at least part of it eroded.

 

Just now learning the terminology and having some of the extant examples will help me immensely. Glad we are sharing this info!

 

Regards, Chris 

[Plantguy]

44 minutes ago, Shellseeker said:

That is why this Research Paper is so important... Yesterday I do not know what the earbones for Sus scrufa and Bos taurus,  and today we can eliminate them for possibilities on earbones we find.  NOT all our fauna is in here but some (Whales/Dolphins, Equus, Deer,  etc ) ARE !!! This paper is pure gold in saving time to ID earbones... 

Here is Equus, with the PDF on the left and one of my finds on the right

Hey Jack, sorry you didnt see that doc earlier, somehow I feel guilty. I see some similarity in your find with the diagram but I'm still not smart enough to say for sure one way or the other. 

 

These things are fascinating!! Hoping this weekend to start cutting up the cow/sheep skull pieces. 

 

Regards, Chris 

[Shellseeker]

38 minutes ago, Plantguy said:

Hey Jack, sorry you didnt see that doc earlier, somehow I feel guilty. I see some similarity in your find with the diagram but I'm still not smart enough to say for sure one way or the other. 

From long history,  you have goodwill built up,  Chris.. I needed to improve my Internet search techniques !!!!

[Plantguy]

18 minutes ago, Shellseeker said:

From long history,  you have goodwill built up,  Chris.. I needed to improve my Internet search techniques !!!!

 

Extant horse petrous example in sketchfab is kind of cool if you havent seen that, maybe somewhat close to the extinct forms:

petrous part of the temporal bone horse

 

Oh, lord, my browser is having fits again...please go to sketchfab and search for petrous part of the temporal bone 
    

Later, Regards, Chris 

Edited January 12 by Plantguy
trying to provide url not the actual link

[Shellseeker]

1 hour ago, Plantguy said:

Oh, lord, my browser is having fits again...please go to sketchfab and search for petrous part of the temporal bone 

Not a problem, Chris  I just dbl clicked on the 4 white lines and the site magically opened up..  It will be interesting to note differences..  Jack

[Balance]

On 1/11/2024 at 8:45 PM, Plantguy said:

 

 

These things are fascinating!! Hoping this weekend to start cutting up the cow/sheep skull pieces. 

 

Grab a 3M respirator from a hardware store  60923 filters usually come with the basic model  $30 or so. Aside from the dust filtering I enjoy the carbon filters ability to neutralize odors. Lots of woods smell horrible while being worked and it’s nice to enjoy the process without looking around for clean air. I also end up sanding horn, antler and even mammoth ivory. All of it smells terrible. Buffalo horn is the worst. 
 

Thanks for starting this thread. Had no idea I was interested in ear bones. 😊

 

 Jp

 

 

 

Edited January 13 by Balance
Added image

[johnnyvaldez7.jv]

I'm still hoping for a defintive ID on this ear bone. I'm going to check out that paper online right now.  I've searched and searched and searched online... and I haven't found anything that looks like this one. I just can't say positively what it's from. It appears to be chambered and there's this single facet on the bottom. I hope through your research you'll come across this. 

[Plantguy]

6 hours ago, johnnyvaldez7.jv said:

I'm still hoping for a defintive ID on this ear bone. I'm going to check out that paper online right now.  I've searched and searched and searched online... and I haven't found anything that looks like this one. I just can't say positively what it's from. It appears to be chambered and there's this single facet on the bottom. I hope through your research you'll come across this. 

Yours is a really neat specimen! I will keep my eyes open.

Part of my problem/interest/learning curve is simply trying to sort thru the various different elements/basic parts of the bones themselves. I remember not liking learning anatomical names/distinguishing features---with my poor memory it makes even more challenging, but I'm fascinated nonetheless. I'm way out of my league with this stuff but I'm having fun with it. 

 

Your specimen shows the irregular complexity within these guys. I hope to cut thru a few of these extant examples to expose a cross section. Often times like in this 6cm long extant miniature horse petrous bone you cant believe the structure. The sketchfab 3d modeling images gives you a real sense how crazy the architechture is...

 

Continued hunting success

 

 

[Plantguy]

22 hours ago, Balance said:

Grab a 3M respirator from a hardware store  60923 filters usually come with the basic model  $30 or so. Aside from the dust filtering I enjoy the carbon filters ability to neutralize odors. Lots of woods smell horrible while being worked and it’s nice to enjoy the process without looking around for clean air. I also end up sanding horn, antler and even mammoth ivory. All of it smells terrible. Buffalo horn is the worst. 
 

Thanks for starting this thread. Had no idea I was interested in ear bones. 😊

 

 Jp

 

 

 

Havent got there yet but I do have one and my pulmonologist gives you a thumbs up!! Be Safe!

Regards, Chris 

[Shellseeker]

8 hours ago, johnnyvaldez7.jv said:

I'm still hoping for a defintive ID on this ear bone. I'm going to check out that paper online right now.  I've searched and searched and searched online... and I haven't found anything that looks like this one. I just can't say positively what it's from. It appears to be chambered and there's this single facet on the bottom. I hope through your research you'll come across this.

When I was a newbee fossil hunter , a TFF member @davehunt helped me understand what an EAM (External Auditory Meatus)   was....

 

https://www.thefossilforum.com/topic/26289-another-mammal-inner-ear-bone/#comment-288399

 

I see one at the top of your last photo... might or might not help continuing your search . I have this feature on some of my more complete Equus petrosals

[johnnyvaldez7.jv]

Thanks @Shellseeker! That definitely looks like an EAM. That's a great link you provided. 

[Plantguy]

Hey you all. Well, I havent started cutting because I havent figured out how to organize and document and get some really good pics but I was drooling over this Bison skull and the still attached petrous bone. Not sure which species this is.. The temporal bone seems to have been damaged but the petrous part is still there!! We've seen that shape in several of the earlier ear bone threads. I can't wait to take more detailed pics and compare to the articles/examples. This is gonna take me awhile...probably a long while at this rate if I dont retire soon...lol.... 

 

Regards, Chris 

 

Edited January 25 by Plantguy
added/clarified comments