Odd Bone?

[worthy 55]

I have not seen a bone with two marrow holes in it before. Any body know what it may belong to?

[Harry Pristis]

I have not seen a bone with two marrow holes in it before. Any body know what it may belong to?

It appears to be an artiodactyl cannon bone. The two cavities are the cores of two fused metapodials.

It looks like the proximal end of a camel bone; BUT, it seems too compressed, front to back, for a camel or a deer. I have four camel bones in my drawer, and they measure considerably larger than your bone. I just don't know what it's from.

[Nicholas]

Peccary Cannon bone?

[Harry Pristis]

Peccary Cannon bone?

Peccaries don't have cannon bones.

[Nicholas]

Peccaries don't have cannon bones.

According to this excerpt Linkthey do.

This excerpt also suggests that "metatarsals are fused proximally" Link

Another source as well on page 3: Link.

All sources so far suggest that in Peccaries metatarsals (in the third and forth) do fuse at least partially.

Another link, Paleo related this time: Link

[Harry Pristis]

According to this excerpt Linkthey do.

This excerpt also suggests that "metatarsals are fused proximally" Link

Another source as well on page 3: Link.

All sources so far suggest that in Peccaries metatarsals (in the third and forth) do fuse at least partially.

Another link, Paleo related this time: Link

And some writers, 'Nicholas', would have it that only bovids and cervids have cannon bones. The accepted use for the term is for two metapodials (3 & 4) fused together to make one bone (with a shaft like a cannon barrel, is the way I remember it).

Do these bone look to you like they're fused into one bone? If they do, I have some that are separated that I can photograph.

"The extreme cases of elongation [of metapodials] are seen in the ungulate orders, Perissodactyla and Artiodactyla. In each order, a progression of elongation can be seen among families. Among perissodactyls, rhinos and tapirs have three or four toes, but the center one (3) is enlarged and bears much of the weight (a condition termed mesaxonic). In horses, the 3rd metapodial is very long, similar in length to the other main limb elements. The other toes are lost or reduced to the point of being slivers of bones that fuse with the 3rd.

"Among the much more diverse artiodactyls, pigs, peccaries and hippos have moderately long metapodials, which are unfused. The third and fourth metapodials, however, are larger than the others and bear most of the weight ( paraxonic). In camels, the third and fourth metapodials are very long and fused for most of their length, although the distal ends remain separate.

"Fusion is complete in bovids and cervids, and the resulting bone is called a cannon bone. Other digits are much reduced or lost." [emphasis added]

Edited October 24, 2009 by Harry Pristis

[Nicholas]

So Harry what about the fossil ID, since Peccaries DO have some fusion couldn't partial fossil be of that proximally fused section of the metatarsals.

Also I was under the assumption since my research last night showed that any fusion of the metatarsals is affectionately called a cannon bone, this would include examples of the partially fused. If you don't like the terminology I can accept that, but there is definitely cases of metatarsal fusion (partial of course) in Peccaries which was my main focus. It is in my opinion that the fossil found could possibly be an partial example of this partial fusion in peccaries much like your example.

[Harry Pristis]

So Harry what about the fossil ID, since Peccaries DO have some fusion couldn't partial fossil be of that proximally fused section of the metatarsals.

Also I was under the assumption since my research last night showed that any fusion of the metatarsals is affectionately called a cannon bone, this would include examples of the partially fused. If you don't like the terminology I can accept that, but there is definitely cases of metatarsal fusion (partial of course) in Peccaries which was my main focus. It is in my opinion that the fossil found could possibly be an partial example of this partial fusion in peccaries much like your example.

Sorry, 'Nicholas', you've misunderstood what you've read; OR, you've gotten hold of some faulty information on the www (that happens sometimes). Your research may have been undertaken with something to prove, rather than with an open mind. That's a mistake that scientists sometimes make.

Here is a single peccary metapodial. You can see that it was tightly articulated with another bone, but it remains intact when separated.

As far as identifying Worthy's bone fragment, I've already offered my opinion. Here is an image of two inches of the paired peccary metapodials. You and Worthy can draw your own conclusions.

[worthy 55]

Thanks for all the information guys.