Articulating a porcupine skeleton part 2

In this post I will talk about articulating the paw and attaching the scapula to the leg.


Once again, I soak the bones.

I start by drilling a hole in the humerus and scapula where they meet. Make sure that the holes are in the right angle!

I attach the scapula and leg, and let the glue dry.

I then work on the harder things:

drilling in the metacarpals and the phalanges.

I decided to not include the carpals (wrist bones) because I only have a few of them and it is very hard to find exactly where they go. 

Here's the name of the fingers, in this case in a  human hand:

In most animals, the distal phalanges are the 'claw bone'

I started with the metacarpals.

Drill a hole in both ends of the bone. it works better if you just drill through the bone (so it makes a 'tunnel'), but I could not because the drill bit was too big. (I used a 1.5 mm drill bit)

 Then, I cut the wire that will connect the metacarpals to the radius pretty long ..maybe 7 or 8 centimeters so  it'll be easier to tie the fingers together later on.  I glue that wire. (To help distinguish between the 2 forearm bones : the radius is thicker then the ulna whilst the ulna is longer. The ulna has a 'hook' at one end which connects with the humerus.)

I drill a hole on both ends of all the metacarpals, and proximal phalanges. (I only drill into one side of the intermediate phalanges)

I put wire like this

(the proximal phalanges and intermediate phalanges are already glued)

I then glued the intermediate phalanges to the distal phalanges (claw bones)...

and glue the metacarpals to the proximal phalanges.

I now have 4 fingers and a leg.

So, I must attach all the fingers to make a hand or paw.

here are the steps I took to attach the fingers:

this is what the completed paw looked like:

 and here's the finished leg. Love it!

Articulating a Porcupine Leg Part 1

*Safety first, always wear a mask when drilling/sawing bones. Bone-dust is not good for your lungs!*


First, you need all the supplies.
This is a list of what I used :
-white glue (I did not use super glue because it dries too fast)
-drill
-1.5 mm bit
-elastics
-wire
-wire cutters
-pencil
-water (not necessary)
-BONES

Before I started, I soaked the bones in water, so there would be less dust when I drill in them.
After getting all my supplies, I took the  ulna (hook shape at the top, picture: on the right) and the radius (left) and marked with a pencil where I wanted the holes to be (do this at every step).  I then drilled equilateral holes in the bones. I also cut small pieces of wire that I will place later.

I then drilled a hole in the ulna and humerus where they meet at the elbow joint.

make sure to check that the bones are at the right angle and that they fit at that angle because I made a mistake and had to drill 2 holes in the humerus.

After I made sure that the hole was okay this time, I  CAREFULLY drilled through the bottom of the radius (wrist joint side ) and into the ulna.

now the bones should look somewhat like this:

I put the pieces of wire with some glue into the holes, and attached elastics to hold the bones in place while I let them dry.

next week I will write about attaching the scapula, wrist, and paw.

Interesting teeth

 A while ago a purchased a opossum skull.  It is probably the skull with the most interesting teeth that I have.

For the people that might be thinking "whats so special about teeth?" I think that the teeth are one of the most important things on a skeleton. You can tell the approximate age, the animal's diet,  sometimes even diseases or mutations the animal had!

(if you are interested in animal teeth and age of the animal, I wrote about my groundhog skull and how old I think it is here: http://theanimalboneyard.blogspot.ca/2012/10/groundhog-skull.html )

So, a opossum,  like a human, is an omnivore. This means they eat anything from fruits to other animals. Since they are omnivores, they have teeth that are specialized to eat multiple types of food. Here are the names of the teeth and other animals that have them.

the opossum has

incisors, like in a horse.  in many omnivores, they are adapted for shearing sharply. 

canines, like in wolves.  they are used primarily for firmly holding food in order to tear it apart.

pre-molars, like in a human.  It has properties of both the  canines and  molars, so food can be transferred from the canines to the premolars and finally to the molars.

molars, like in a cow. Molars are used to grind food. 

humans have every type of tooth listed above.

a coyote skull looks  like this, notice the teeth near the back of the mouth, they are sharp whilst in a opossum they are flat.

The coyote, like most carnivores, have a pair of teeth called  'carnassials'.  The opposum does not.


So the opposum has similar teeth to a human, but has canines more like a coyote, or a dog. And the opposum has no carnisials.
The incisors resembles the teeth of a horse or donkey because they have  incisors on the maxilla (top jaw) and the mandible  (bottom jaw) unlike a deer which only has incisors on the mandible. And, unlike herbivores, opposums do not have a diastema. (gap between teeth, usually between the molars and incisors).

 

But they do have flat molars, used for grinding like in cows.

 

the opposum has the same teeth as many animals yet lack others that the same animal has.

and that is why I think the opposum has interesting teeth.

 

 

groundhog skull

In this post I will talk about my groundhog skull, and why I think it was young.

the groundhog dental formula is:

I : 1/1   C : 0/0   P: 2/1   M: 3/3 = 22    (11x2=22)

or

upper: 2 ; 0 ; 4 ; 6

lower: 2 ; 0 ; 2 ; 6

which means:

a groundhog has 1 incisor, 0 canines, 2 premolars and  3 molars on each side of the top jaw, so they have 2 incisors, 0 canines, 4 premolars and 6 molars on the top jaw. (12 teeth)

they have 1 incisor, 0 canines, 1 premolar, 3 molars on one side of the upper jaw therefor has 2 incisors, 0 canines, 2 premolars and 6 molars on the entire bottom jaw. (10 teeth)

ground hogs have 22 teeth.

--

Unfortunately, I do not have the lower mandible of the groundhog. But the cranium has room for all 12 teeth (some fell out post-mortem, but all the teeth have grown) I have one incisor, 6 molars, and 2 of the premolars on my skull. There are only 3 teeth missing.

Compared to my groundhog bottom jaw (not from the same animal) this skull has sharp teeth, suggesting this skull is young and\or the other animal from which I have the jaw was very old.

the 'sharp' teeth on my groundhog skull

the jaw from older groundhog

On this skull, the auditory bullae (inner ear bones), the back of the brain case and the nasal bones are missing.  I know that in deer, when the back of the brain case is missing it is a sign the animal was young. Also, the bones are not fused, which in most animals, means the animal was not fully grown. (It is possible that the brain case has been crushed, but because of the lack of fusion in the bones and sharp teeth I think it is more likely it is missing because the groundhog was young and the piece of bone just fell off.)

The pictures show the missing auditory bullae and braincase. In the first picture,  you can clearly see the bones that are not fused.

In conclusion, this groundhog had all it's teeth, but they where not worn down. That means that the animal was not as old as my groundhog jaw. The bones are not fused, causing the brain case and auditory bullae to detach and no longer be on the skull, And that happens to young animals. And that is why I think the skull was from a young groundhog.

old moose bones

a couple weeks ago my dad and i went to a different forest, i'm not sure what it was called. We walked for about 5 minutes and we found a ground hog skull! I think someone must have placed it there, because there where no bones around, and it looked 'perfectly placed'.. it just didn't seem natural. oh well, its a skull either way. It made me feel very lucky that we found something so quickly, and i hoped we would find more. Well, my wish came true!


Maybe 10-15 minutes after we found the skull, i saw a bone from a distance. When i went to check it out, I realized there wasn't 1 bone, but a lot of bones! there were some vertebrae, 2 scapula, ribs and a lot of leg bones (femur, tibia, fibula, etc.) . Unfortunately, there was no skull... but i did keep the 2 scapula, and 2 vertebrae.

after that, we started seeing bones EVERYWHERE.
here are some bones we saw that i didn't keep:

a very large bone (do not know what it was)... could only be from something as big as a cow, horse or moose
a bird sternum, it was from a small bird.
2 deer jaws with a couple of teeth
a couple bones here and there

and other bones i did keep :

The last thing i found was definitively the best: moose bones.
Two of the reasons that they are so special is these bones are VERY old. I know this because the bones no longer felt like bones, they felt like wood, there are very large cracks in them, they are stained green and brown, they broke very very easily and Moss and plants where growing on them! the other reason they are special is because there aren't many moose in the area or any area near where i found them. The moose are all up north. Since they are old, maybe there was a now 'extinct' population of moose living in the area.

out of the bones i kept 1 vertebrae and 3 teeth (I think one is a molar and the 2 others are pre-molars). I did not take anything else because i did not know if i could get the moss and plants off, and the bones looked and felt so weak i did not know if they would last very long.Although i did not take some more moose bones, I am very satisfied with our walk!

how long ago did the porcupine die?

My dad and I went back to lime kiln trail a week ago. we walked for a while, exploring new parts of the forest and saw 3 woodpeckers (either downy or harry woodpeckers). we also found  a gartersnake (which I got to hold).




As we where walking along some burnt trees, my dad spotted something. At first I didn't believe him, because we hadn't seen anything yet and i was surrounded by mosquitoes and flies (which doesn't help).  but when I got to where he was, I saw it. A porcupine skull with the spine. I could tell it was a rodent because of the orange  front teeth. it was too big to be a muskrat, and too small to be a beaver. (neither the muskrat or the beaver would be in the middle of the forest anyway). When we got home I did some research (to make sure I was right) and it was definitively a porcupine. Here it is with the other bones:

and of underneath the skull

at first my dad and i thought it might have died during the fire, of smoke inhalation.  but with the help of my aunt and cousin, i have concluded that the porcupine probably died before the fire. this is  the main reason why:

when we found it, there where no limbs. that means that another animal carried them away. If the porcupine had died in the fire, there would be no flesh left, hence the bones being burnt. and if there was nothing left but bones, carnivores would not take the limbs.

the fire was 2 about 2 months ago, meaning this porcupine died at least 2 months ago.

another example of the limbs being carried away from the body is my deer leg bones i found a couple weeks ago.We found the limbs, but no body.

i am really happy i have this skull, because it is the first skull we found. (with no flesh)

burned bones

Last weekend, my dad and I went to Lime Kiln trail in search for bones.We walked for about fifteen minutes, finding nothing. Eventually we got to ruins of this old building (there are a lot on this trail) and we started walking off trail. After a while we saw a meadow and decided to check it out.  We were rewarded with nice deer leg bones; a femur (thigh bone), a patella (kneecap) and possibly a tibia (shin bone). We started to look around to find the rest of the body. My guess as to why the leg was separated is because carnivores often carry the limbs away. After  a couple of minutes, my dad found mandibles. I'm pretty sure they are deer, because of the lack of teeth in the front of the jaw and  the teeth are from a herbivore. Unfortunately they were green, probably from the moisture in the spot that we found them... I was worried it wouldn't come off, but we took them home anyway. He also found a couple of thoratic (mid back) deer vertebrae ( presumably the same animal) around the same area.

We didn't  find anything else, so we decided to head back towards where we found the deer leg bones, and started looking on the opposite side. I found about 4-5 more deer bones and antlers (probably moose, because of the shape and size) but we did not take it because of the extensive damage.

As soon as I got home, I put the jaws, a couple small bones and one of the patellas in peroxide.After a day or two I checked on them and the jaws where still very green, I waited one more day and they had not changed. So, I  decided it would be best if I didn't keep the green bones, but instead kept only the teeth. After I took the rest of the bones out of the peroxide,I  noticed something; they had some brown and black marks on them. I thought it was just dirt, so I tried to rub it off, but with no success. After they dried I realized that these bones had been through a fire: they were burnt. Last month here was  a forest fire in this area, and that is why the bones are burnt.

some old cans and other metal objects found in the forest