Jump to content

Quiz -- This Is Not An 'easy' Bone Like The Others


Harry Pristis

Recommended Posts

Here is an exquisitely-preserved little bone which is about 20 Ma old. It's almost the length of a king-size cigarette. The challenge:

What sort of bone is it?

What sort of animal is it from?

Post-cranial bones from this period are not as well known as teeth and jaws. It may be difficult to assign this bone to any specific genus (forgive the understatement!); however, there are characteristics of the bone which suggest a Parvorder or possibly even a specific Family. Can you pick 'em out?

An aspiring vert-paleo collector can "make his bones" with this one! (Sorry, Roz, this is NOT a wolf.)

Good luck in the pursuit of gold and glory!

post-42-1224529904_thumb.jpg

http://pristis.wix.com/the-demijohn-page

 

What seest thou else

In the dark backward and abysm of time?

---Shakespeare, The Tempest

 

Link to comment
Share on other sites

I think it is definatly a Femur, but I think the size is to small for a normal horse or camel. This is the size of a big raccoon or a bobcat. The thing that I think is wierd is that the joint surfaces seem to be at a wierd angle. The top ball joint is close to being parallel with the lower hinge joint,instead of at a right angle. Hope my untechnical terms and spelling make sense.

Dan

Link to comment
Share on other sites

whatever it was wasn't very big. strange angles? a waddler? my guess would be a small, shelled chupacabra.

Link to comment
Share on other sites

It's not a femur. It is a humerus. My guess is beardog humerus.

Bingo! It's not a femur! It is a humerus.

Thank you, Auriculatus. I was beginning to become dismayed after posting all the different humeri in past weeks! Oh, well. All shark teeth look alike to me. :rolleyes:

The bear-dog ID is not right, though.

This is a case unlike horses or camels where there is a pronounced progression of size over time (Miocene forward, in this case). I am not saying that this animal survived, but the Family did (unlike the Amphicyonidae).

Speaking of Amphicyonids, here's an image of the distal portion of a beard-dog humerus with the mystery bone posed on top.

What I'm looking for is an ID with the logic supporting your thinking such as Pool Man and Tracer offered.

There is a large number of small animals, but only one Family produced this bone. There is a clue in this new image -- an esoteric one -- to what sort of critter (the Family) this bone represents.

post-42-1224567623_thumb.jpg

  • I found this Informative 1

http://pristis.wix.com/the-demijohn-page

 

What seest thou else

In the dark backward and abysm of time?

---Shakespeare, The Tempest

 

Link to comment
Share on other sites

hmmm well since you drew the comparison between the beardog i would say its some sort of small carivore. Fox perhaps? although due to the weird surfaces i dont think it would be from something that simple knowing you Harry! hmm... I guess different surfaces can alow for different joint movements, some sort of climbing carnivore? some sort of cat perhaps? Although again, knowing you Harry, i dont think so! Badger, pretty much anything else such as weasel and such from that genus is a possablity...

Im lost! maybe my blab makes some sort of sense to someone on here?

"Turn the fear of the unknown into the excitment of possibility!"


We dont stop playing because we grow old, we grow old because we stop playing.

Link to comment
Share on other sites

Guest Nicholas

I'm going with skunk humerus. It is a Miocene animal, where certain branches of the family disappeared from that location, but some still remain such as the striped and spotted.

Link to comment
Share on other sites

hmmm well since you drew the comparison between the beardog i would say its some sort of small carivore. Fox perhaps? although due to the weird surfaces i dont think it would be from something that simple knowing you Harry! hmm... I guess different surfaces can alow for different joint movements, some sort of climbing carnivore? some sort of cat perhaps? Although again, knowing you Harry, i dont think so! Badger, pretty much anything else such as weasel and such from that genus is too small me thinks?

Im lost! maybe my blab makes some sort of sense to someone on here?

Fox? Weasel? Badger? Skunk? Any of these is a reasonable guess based on size.

Perhaps the clue is too esoteric. I've identified the clue in another image; what can you do with it?

post-42-1224605402_thumb.jpg

http://pristis.wix.com/the-demijohn-page

 

What seest thou else

In the dark backward and abysm of time?

---Shakespeare, The Tempest

 

Link to comment
Share on other sites

Define "metatherian" for us, 'don.

Similar to marsupial I believe, I was going for oppossum humerus but mixed up the names. But I think think the animal would be smaller than that...hmm.

Link to comment
Share on other sites

I think I may have it, taking note of the entepicondylar foramen I am going to say raccoon humerus.

Raccoon is a reasonable guess, based on size of the bone. How does the existence of an entepicondylar foramen help you, Nicholas? Why not a little canid . . . a chihuahua-size dog? . . . or a viverrid? . . . or a lagomorph (rabbits, et al.)?

A didelphid (such as an oppossum) is a reasonable guess beause . . . ?

By the way, the entepicondylar foramen (EECF) is the canal which is traversed by the median nerve and the brachial artery.

This is an exercise in deductive reasoning. There is information upon which you can base your ID. Persevere! :)

http://pristis.wix.com/the-demijohn-page

 

What seest thou else

In the dark backward and abysm of time?

---Shakespeare, The Tempest

 

Link to comment
Share on other sites

Guest Nicholas

Entepicondylar foramen helps limit the categories, it is mainly present in mammals, exceptions are primitive reptiles and some amphibians. Chriopterans, sirenians, ceraceans, proboscideans, hyracoids, perisodactyls, artidactyls, and lagomorphs never ever have one. Taking in that your bone is Miocene this one ultimately limit the bone to being mammal, given your range of size I assumed Raccoon having an Entepicondylar foramen would make educated guess.

You mentioned marsupials, and your are correct in saying that didelphid because didelphids have Entepicondylar foramen. However it is usually absent in dasyurids.

Link to comment
Share on other sites

Guest Nicholas

Oh I forgot to mention the Entepicondylar foramen is lost in running mammals such as: ungulates, dogs, and hyaenas. That is why It can't be a dog, and I do believe viverrids are under that classification of running mammals. As I mentioned before lagomorphs never have an Entepicondylar foramen.

Link to comment
Share on other sites

Oh I forgot to mention the Entepicondylar foramen is lost in running mammals such as: ungulates, dogs, and hyaenas. That is why It can't be a dog, and I do believe viverrids are under that classification of running mammals. As I mentioned before lagomorphs never have an Entepicondylar foramen.

Alright, Nicholas! You win the golden kudo for your research!

post-42-1224626649_thumb.jpg

The answer I was looking for was humerus from a representative of the Parvorder Mustelida, Family Mustelidae (weasels, skunks, otters, et al.) or Family Procyonidae (raccoons and coatis).

For those who didn't do the research, the entepicondylar foramen (EECF) is never found on the humerus of perissodactyls (horses, tapirs, et al.) nor on the humerus of artiodactyls (antelopes, camels, et al.), nor is it found in lagomorphs (rabbits and such).

The EECF is absent in hyaenids, bears, and canids (including foxes and chihuahuas).

The EECF is found in didelphids (opossums) and in shrews and moles! (Micro-fossil collectors take note.)

The EECF is present in felids (no cats from this site - too early), in viverrids (all Old World), in amphicyonids (bear-dogs), and in mustelids and procyonids.

I think this humerus is from a small mustelid, rather than from a much rarer procyonid. Four mustelids and two procyonids have been identified from this site. I favor mustelid because of the robust muscle attachments on the humerus which suggest powerful digging/grasping forelegs.

This information about the EECF might be worth remembering. You may get an opportunity to dazzle your friends with your knowledge of this esoterica. Post-cranial skeletal information is often neglected by collectors.

  • I found this Informative 1

http://pristis.wix.com/the-demijohn-page

 

What seest thou else

In the dark backward and abysm of time?

---Shakespeare, The Tempest

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...