Dichotomous Key Exercise

Dichotomous Key Exercise (15 points)

Assignment: Working in pairs and submitting a single key for the pair, your task is to generate a key that will allow the user of the key to end with the number and name of the vertebra. The dichotomous key you have used to identify the orders of insects is the model you should use. Please include the number of the box you used in the laboratory on your key. The boxes are not to leave the laboratory. Refer to the articulated cat and fish skeletons for position orientation. Before turning in your assignment, the key must be evaluated by four separate individuals who have signed your work. Some hints: Avoid the use of exact measurements or colors. E.g. Use a comparative statement like...neural spine length greater than twice the width of the centrum or use ratios. Use precise descriptions for locations. E.g. Lateral surface of centrum has multiple shallow recesses. (Remember, the reader will only have a single vertebra available and not the entire box to study). Some useful vocabulary: See the illustrations of the two vertebrae at the bottom of the page to locate the neural spine, hemal spine, centrum, neural canal, and transverse process. spine convex conical process=projection concave diameter ridge flat width bump porous length foramen (plural foramina)= a hole perforate vertebra (plural vertebrae) oval fossa=depression=recess circular

Directional terms (See Hickman et al. 2008 pg 188 Figure 9-2): anterior (toward head) posterior (toward tail) dorsal (toward back) ventral (toward stomach) medial (toward midline) lateral (away from midline)