François -- The number of carpal and tarsal elements of almost all mammals
is the same, and therefore, you would be perfectly correct in using one of
two systems for naming the bones. The two systems are the veterinary
system and the zoological system. There is also a third system, which is
the medical system, but that is only to be used for the remains of humans
(and even then, it would be OK to use the zoological system).
There is a mnemonic device to help remember the names of the bones in the
zoological system; there is also one for the medical system. Naturally
they are a little "risque" because made up by fun-loving graduate students
in ages long ago. The one for the medical system is Never Lower Tillie's
Pants, Mother MighT Come Home. That is, beginning with the proximal row:
radial/medial to ulnar/lateral side: Navicular (also sometimes called
"scaphoid"), Lunar, Triquetral, Pisiform; then the distal row, medial to
lateral: Magnum (also called Trapezium), Trapezoid, Capitate, Hamate. But
as I said, you wouldn't be using this system for a beaver.
The zoological mnemonic device is: Spanish Ladies Cannot Piss, Therefore
They Must Urinate, and it stands for: Scaphoid, Lunar, Cuneiform, Pisiform
in the proximal row, Trapezium, Trapezoid, Magnum, Unciform in the distal
row.
The veterinarians are, by contrast, logical but rather boring (old vet
students must have been exercising their "risque" efforts elsewhere): The
proximal row is Radial carpal, central carpal, ulnar carpal, accessory
carpal; the distal row is numbered medial to lateral "distal carpal 1",
"distal carpal 2", and so forth.
So, assuming you have noodled out how to articulate either a right or a
left carpus -- and you can do this by looking at the pictures in Sisson
and Grossmann of the dog carpus -- you should be able to assign each one a
name from one system or the other. This is a headache but, I think, a
valuable exercise too. Cheers -- Dr. Deb
> Thanks to the photos that Sheila provided me, I can now side "my" beaver
> bones, but am still unable to name them, which is a shame as many of them
> bear cutmarks. All the references that I know either do not include
> carpals and tarsals other than the calcaneus and the talus, or do not
> include rodent bones. Any input would be appreciated.
> François
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