Answer and Explanation:
A jaw might provide you much information about its function and about the animal´s adaptations to different scenarios. These structures are very useful in characterizing a group as a new species. Of course, there are many other factors to consider as well.
When you are working with the mandibles of different known species and the mandible of a new species, and you need to get information about the species behavior, such as its diet, you need to compare all the pieces involved in the feeding act. This is,
- Teeth. Teeth are the most evolved pieces in animals, and thus, provide important information about species. They are very important in taxonomic identification and phylogeny. Animals might be homodont or heterodont, which means that all teeth are equal, or there are different kinds of teeth with different functions. According to the diet, teeth vary in shape, and thus you can find herbivore teeth, carnivore teeth, omnivore teeth. The number of teeth might also vary according to the feeding strategy and the diet of the animal.
- Processes. The shape of the mandible is another very important component. The sizes of processes might provide information about muscular development, and through this knowledge, you can assume the importance of the mandible while feeding, and the strategies used to feed according to their diet. Animals might develop different muscles that are more or less useful while feeding on different prey. Processes are the insertion point of these muscles, so according to their size, you might estimate the muscle mass, and thus, the muscle use.
- Length. The mandibular length of many species is correlated with their prey and feeding strategy. By meassuring the ramus you might also infer the diet.
So, in any case, if you have many jaws belonging to different known species and you also know what is the principal diet of these species, then all you need to do is to compare the teeth, processes, and sizes of your new species with the ones of the known species. By comparing all these structures you will have strong evidence of your species diet.