Collection of Animal Skulls

Eastern Cottontail 1

• Gender: --
• Age: Adult

This was a very challenging skull to process because rabbits are so greasy. Overall it took almost a year of alternating maceration, ammonia, and hydrogen peroxide. Despite these difficulties, I am happy with the result.

Eastern Cottontail 2

• Gender: --
• Age: Adult

This is a partial skull found in the woods in NY. No cleaning needed to be done, as the skull had been there for awhile.

Eastern Cottontail 3

• Gender: --
• Age: Adult

This is a partial skull found in the woods in NY. No cleaning needed to be done, as the skull had been there for awhile.

Eastern Cottontail 4

• Gender: --
• Age: Adult

This is a partial skull found in the woods in MI. No cleaning needed to be done, as the skull had been there for awhile.

Groundhog

• Gender: --
• Age: Adult

This was found behind the feed bin at a friend's chicken coop. Groundhogs are one of the largest rodents in the United States.

Eastern Gray Squirrel

• Gender: --
• Age: Adult

This was found in the woods underneath a tree.

Virginia Opossum

• Gender: Male
• Age: Adult

This specimen was found in our woods. He was likely elderly; two of his vertabrae were fused together: a sign of arthritis. He also had a rib bone that broke and healed over crooked. Looking at the skull, he had damaged his forehead area and it healed over. This injury still hurt though, as he chewed only on one side, unevenly wearing down the teeth. There are small holes all over the skull. This is a sign of a parasite. Overall, this opossum had quite a few injuries, and since there are no broken bones in the entire skeleton it is likely that he died from one of these injuries.

Striped Skunk

• Gender: --
• Age: Adult

This specimen is from a Striped Skunk, which is the only species of skunk found in Michigan. Skunk skulls can be identified from their size, usually three or more inches in length, and by the sharp canine teeth and lack of incisors which separate this skull from the skulls of rodents. The striped skunk has sixteen upper teeth. This skull measures 7 cm long, or 2.75 in, and is approximately 4.5 cm wide (1.77 in). On the forehead of the skull is an area of bone that appears to be bubbly and has holes. This damage is the result of the parasite Skrjabingylus chitwoodorum. This parasite is a type of metastrongylid worm which have larvae that move from the host's mouth and into the frontal sinuses. This is where the larvae become adults. Infection by chitwoodorum can cause damage to the frontal bone of the host's skull. This damage ranges, from slight bulging in the bone to larger lesions and holes (Journal of Wildlife Diseases, 2020). This skull had a fairly moderate case, with a large bulge and holes. This skull belonged to an older adult. The age can be identified by the porous bone in the snout that often occurs in older animals. In addition, the cranial sutures, plates of bone easier to see on younger specimens, have fused and it is impossible to see them. The teeth are also very worn down.

Raccoon 1

• Gender: Male
• Age: Juvinile

This was a baby. We saw him and his siblings one day, two ran in one direction and the last ran in another. I suspect that he wasn't able to find his siblings, and couldn't survive without him. I found the skeleton in a drainage pipe near where we saw them. I know that he is a male because he has a baculum (penis bone) that I previously mistook for a rib.

Raccoon 2

• Gender: --
• Age: Adult

This was found in a pile of raccoon skeletons that someone shot.

Raccoon 3

• Gender: --
• Age: Adult

This was found in a pile of raccoon skeletons that someone shot.

Raccoon 4

• Gender: --
• Age: Adult

This was found in a pile of raccoon skeletons that someone shot.

Raccoon 5

• Gender: --
• Age: Adult

This was found in a pile of raccoon skeletons that someone shot.

Raccoon 6

• Gender: --
• Age: Adult

This was found in a pile of raccoon skeletons that someone shot.

Raccoon 7

• Gender: --
• Age: Adult

This was found in a pile of raccoon skeletons that someone shot. It has a clean hole on the right side of the skull and a BB bullet found nearby indicates that this raccoon was indeed shot by a human.

The skull is approximately 11 cm long (4.33 in) and 7 cm wide (2.75 in.)

This animal suffered a nasty bone disease in the right side of the skull. The right lower jaw bone is especially damaged, with the articular process, condyloid process, and coronoid process, the parts of the jaw that hinge unto the upper skull, are practically destroyed. The area around the articular, condyloid, and coronoid processes is a darker color than the rest of the bone, and is porous. It may be an extreme case of osteoporosis, or possibly a form of cancer. The incisors on the left side of the lower jaw are crowded together.

Looking at the upper half of the skull, similar damage can be seen right above the right molars and last premolar. The first molar is damaged, but it is difficult to tell if the damage happened post-mortem or when the animal was alive. Moving on to the right zygomatic arch, similar porousness is seen spreading all the way to where the right side of the jaw hinges to the rest of the skull. The right auditory bulla, one of the bones responsible for hearing, also has a patch of porous bone. The left side of the skull, and the left jaw, also show slight damage. At the back of the skull, a little to the right of the foramen magnum, the hole in the skull that attaches to the spine, there is a small hole a little less than a centimeter. It seems that the bone has started to partially heal while the raccoon was still alive.