| Brooklyn College
City University of New York
|Lab #6, Assignment #1||
|The next thing we want to do is
determine whether potential modern dinosaur analogs have a leg structure that is similar to
the leg structure seen in dinosaurs. We are interested in the general aspects of leg
structure, not in details. Thus, at this early phase of investigation on this subject, we
need not be concerned with such matters as the length of the leg or whether the foot is
plantigrade or digitigrade.
We can also keep in mind that within vertebrate classes skeletal anatomy is a strongly
conservative character. What this means is that all members of a vertebrate class have the
same basic leg structure. Thus we can consider the legs of a single member of a class as
representing the class as a whole (but keep in mind also that there are a few obvious
exceptions to this rule - snakes for example).
The figure below shows one species typical of each of the four tetrapod vertebrate
classes. Examine each one to determine whether the skeletal structure of the leg is similar
to that diagrammed on the previous page, and to dinosaur leg structure. Consider only rear
2. Do the cat (mammal), iguana (reptile), frog
(amphibian), and crane (bird) have the same general leg structure as
diagrammed on the previous page?
3. Do they have the same general leg structure as Tyrannosaurus?
4. What can be said about the suitability of these animals, and the groups they
represent as potential dinosaur
analogs with respect to leg structure? Have we narrowed the field of potential
ASSIGNMENT #1: Email me your answers to questions 1 through 4.
Deadline - Friday, April 27 at 4 PM.