Brooklyn College City University of New York

FIELD TRIP GUIDE

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3. STANCE OF ALLOSAURUS: If the term "foot" is defined in a functional context, ie., as consisting of bones that contact the ground, the human foot may be seen to consist of all bones below the ankle, as well as the ankle itself (refer to the sketch on the previous page). This produces a stance in humans termed plantigrade. In cats, however, it is only the bones of the toes that contact the ground (see sketch on previous page). The foot of a cat thus consists only of its toes. The ankle is actually part of the leg. This kind of stance is referred to as digitigrade. Is Allosaurus plantigrade or digitigrade? Why? Is it more like a human or a cat in this characteristic?

3.  FEET OF ALLOSAURUS:  Examine the feet and lower leg of Allosaurus. How many toes does Allosaurus have? How many toes reach the ground and form the "functional" foot? Imagine the bones of the foot covered with flesh as was the case when this specimen was alive. Draw a quick sketch of the shape of a footprint that this allosaur would have made if moving on soft ground. How large would the footprint have been? What would have been the approximate length of the print (where length = distance from heel to tip of the middle toe)?

4.   ARMS & HANDS OF ALLOSAURUS:  Examine the arms and hands of Allosaurus. How many fingers does Allosaurus have? How many bones in each finger are there? Is this the same or different than in human hands? If you are not sure, count the number of bones in one of your fingers from knuckle to finger tip. What might the hands of allosaurs have been used for?