Before the holidays, my friend, Lenore, and I were out in the woods gathering greens and berries for our natural Christmas “displays.” We came back to our homes with arms loads of cedar, pine, soap berries, cherry laurel berries, smilax berries and possum-haw berries. And, I came home with the best of the best. An animal skull!! But my happiness was short lived when the family would not let me put it on the top of the Christmas tree.
After the holidays and the decorations stored, I decided to research my “find.” Identification can be determined by several methods. The best way to identifying a skull to species is with the use of a dichotomous key. This tool allows a person, through a series of questions, to identify an organism to species by process of elimination. The questions are “either/or” (dichotomous) choices. These choices are arranged in “couplets,” or pairs of statements. From each couplet, you choose the statement that best describes the skull. This map will lead you to the name of the mammal or group of mammals or to another couplet. You have to have to patience to work through the steps in sequence until you have a tentative identification.
In my Master Naturalist classes, we used a dental formula - counting the teeth. Even though some of the teeth are missing in my skull I was able to determine this skull has 40 teeth, and so does a raccoon. The dental formula for a raccoon is 3 incisors, 1 canine, 4 premolars and 2 molars or 40 teeth. It is written as such:
Another way to tell is turn the skull over and look at the hard palate bone (the roof of its mouth). In a raccoon, this bone will go past the molars.
Raccoons are opportunistic omnivores with a very broad diet. Their diet consists of roadkill, insects, frogs, birds, snakes, small mammals, slugs, and earthworms. Some of their favorite foods are fruits and MY tomatoes. Omnivore teeth are a mix of herbivore and carnivore teeth. Their sharp-edged incisors and long canines look like those of carnivores, though the canines are not as sharp. The cheek teeth are a blend of herbivore and carnivore teeth - they do not have the tall, sharp points of the carnivore, but do have more groves and blunt points than herbivore teeth.
And, there you have it! Next time you find a skull, try using a dichotomous key and also a dental formula. The cat is getting suspicious and the family doesn't like the ickyness of a dead animal on the kitchen table, so I must dispose of the skull. Naw, maybe I will just hide it.)
Shameless plug here - a new Master Naturalist class is beginning at the Tyler Nature Center on February 23. It is sponsored by Texas AgriLife Extension Service and Texas Parks and Wildlife. Check out their web site: