Skulls Activity

This activity will take a lot of effort to get ready to go, but the results will be valuable for many years. I have a collection of over 40 different animal skulls, twenty of which I share with campers during the summer. I obtained my initial collection by picking up road kill and simply letting the skin rot off in a cage in my back yard. Others may prefer boiling or Dermestid beetles. In Pennsylvania, one must have a salvage permit in order to pick up road kill, so check with your game officer before proceeding. You can also obtain specimens from local hunters and taxidermists who often do not use the skulls of ducks.

Using these skulls, one can easily lead children through the detective work that it takes to identify a skull. Skulls also provide an impetus for thinking about animal's diets based on their dental adaptations. The discussion of adaptations helps campers to appreciate the complex and wonderful ways in which God has provided for each organism in order to fulfill its needs.

Begin the session by discussing the four different kinds of teeth: incisors, canines, premolars, and molars. Incisors work basically like scissors (demonstrate with scissors) and animals use them mainly to cut pieces off of larger food items. Ask the campers what they use their front teeth for, and draw the conclusion that incisors are particularly important for animals that eat plants. Canines work like knives and are specialized for ripping and tearing, especially the flesh of other animals. One can infer that animals with well-developed canines are meat eaters (carnivores). Premolars and molars are difficult to distinguish from each other, because both are used for grinding food material, working like a mortar and pestle. Premolars generally have only one cusp (indentation on the top surface) whereas molars have two; molars are also further back than premolars. Animals with virtually flat molars eat lots of plants and animals with relatively sharp molars eat meat.

Skulls can be identified by the number of each kind of tooth, counted on only one side of the skull. We count only one side of the skull because the other side is identical. I illustrate the half a head concept to campers through a raccoon skull cut in half and mounted on plexiglass. I also introduce the dental formula on this example by having the number of incisors, canines, premolars, and molars counted and labeled. A dental formula works as follows: I 3/3, C1/1, Pm 4/4, M2/2 which means that the organism has three incisors on top and three on bottom, one canine top and one bottom and so on. Along with discussing the dental formula, I also remind them that simply counting the total number of teeth can be a valuable beginning point. For example, opossums have a distinctive number of teeth. If I were to count 50 teeth in a skull (25 in a half skull), I could identify it quickly as an opossum.

Next, hand out skulls to all the campers or perhaps pairs of campers, as well as detective guides containing a variety of skull formulas on them. Ask the campers to identify their animals and try to guess what the animal might eat. Give the campers time to work on the problem, as even older campers find this a challenging activity. Help them to count teeth that have fallen out and reemphasize the half a head concept. Have campers present their identification to you before having them share about their animal to the entire group.

As the children present, draw attention to the particular adaptations in each skull. For example, foxes have an extended snout, deer entirely lack canine teeth and upper incisors, and so on. This stage will depend on your own knowledge of your own collection, which you can develop through a variety of sources. Emphasize the uniqueness of each organism and how well it corresponds to its survival needs. Since God helps these animals to survive in their different situations, how much more does God know our situations and can provide for us in any circumstance we may find ourselves.