Q: Tell us something about the skeleton of mustelids and ferrets.
 
A: They are made of bone.  Next question.
 
Actually, I'm in love with the skeleton of mustelids because of their
strength and functionality.  The skeleton is superbly adapted to the
evolutionary habits of the little beasties, and shows little variation
throughout most of the Mustelids; in other words, the skeletons of all
mustelids are pretty much the same.
 
I'll start out with the skull.  In the weasel group in particular (which
includes ferrets, mink, and polecats) the skull is long and slender.  The
mandible attaches about halfway down the skull, and the ridges along the top
of the skull (the sagital crest) and the back of the skull (the occipital
and nuchal crests) are extremely developed.  This shows the bite of the
weasel group to be powerful, perhaps the most powerful, pound per pound,
than any other member of the Carnivora.  The skulls look pretty much the
same, down to the teeth, and differences in size can almost be used to
differientiate species, but sexual dimorphism can confuse the issue.  The
skull is quite similar to other mustelids, although the farther away the
evolutionary relationship, and the larger the specis, the shorter and fatter
the skull, and the closer to the back of the skull the mandible attaches.
So in badgers, the skull is relatively broad, and the mandible attaches
closer to the hole that allows the spinal cord to exit (the foramen magnum).
In *very* generalistic terms, the skulls most similar to the weasel group
would be the skunk group, followed by the fisher group, and the otter and
badger groups.
 
The skeletons of all mustelids are generally the same, with a few exceptions
in the otters and badgers.  The badgers are more adapted to digging than
most mustelids, and the otter are more adapted to water.  (If you ever get
the chance to compare eared seal skeletons to those of the sea otters, you
will be quite amazed at the similarities.  With today's genetic techniques,
the relationship of the seals and mustelids has pretty much been shown, but
even 100 years ago, just using bone, the relationship was hypothesied by
Owens and others.)
 
Overall, the vertebral column of mustelids is long and supple, allowing the
animal a gr4eat deal of flexibility and power.  In the sprinting mode, the
muscles along the back release a great deal of energy, and even though most
ferrets don't show it, the ability to reach warp speeds (I once had a fisher
run over my foot to get to a tree.  All I saw was a brown streak, and I
could only identifiy the animal by waiting a cuople of hours until it poked
its head out of a hole.) The supple back allows a great deal of flexabilty
in changing directions while running, for carrying heavy loads (2-3 times
their body mass in typical), and for turning around in burrows and on tree
limbs.  It also helps in jumping and landing, and acts as a shock absorber
in falls.  Most mustelids can leap 2-4 times their body LENGTH and in some
cases more, which in humans would be 10-25 feet depending if you were me or
some exomorphic basketball player.  Much of the power for those leaps comes
from the muscles of the back, and their relationship to the vertebral column.
 
In almost every mustelid (not as noticable in the fisher group), the limbs
are short and powerful.  This is most noted in the badgers, who can dig
faster than Bubba Bill can run.  Short limbs allow access to burrows, but
are also quite powerful for digging, running and climbing.  As a result,
they are some of the strongest animals on the planet, pound per pound.  To
use a human example, I *love* to find giant guys and bet them that I am more
strong, pound for pound, than they are; I've never lost, not would most
normally-sized people in relatively good shape.  The bet is even better when
I bet my daughter is stronger, lb per lb, than they are.  I've humiliated
several football players with that one.  For example, a 100 lb girl lifts
110 lbs over her head, while a 250 lb ectomorph lifts 250 lbs.  The girl is
lb per lb stronger, and Elizabeth gets $20 towards her college fund.  If the
guy is a weight trainer, it throws off the calculations somewhat, so I
define strength as endurance and still win, he he)
 
The same principle applys to mustelids.  Due in part to the angle and
position of the muscle attachments, even though they are tiny little
creatures, they are quite strong for their size.  This makes for a great
little digger and climber, not to mention leaper.  The short legs also make
for a good set of shock absorbers, which, along with the powerful vertebral
column, allows leaps exceeding 5-10 times their body length without serious
injury.  Inagine being about to jump down from the 3rd or 4th floor of a
building without injury and you get an idea of the relative distances these
little guys can jump.  (A great deal of this also has to do with body mass
as well).
 
As far as I know, all members of the mustelid family have all five digits
front and back; most other carnivores have tended to lose the thumb and
great toe, or at least minimalized it to a non-functional part (like our
appendix).  All male mustelids, like their carnivore cousins, have a bony
penis called the baculla or os penis.
 
Overall, the skeleton is that of a powerful animal, able to leap/dig, carry
heavy loads, and run fast.  The skull displays the potiential for a very
powerful bite (duh).
 
Mo' Bob and the 18 Bone Biters (In memory of Gus)
[Posted in FML issue 1735]