Chapter 2 – Herpetology Questions

1.                  What do the following terms mean and in what context do we use them?  

-         phylogenetic systematics                       -           shared derived characters

-         cladistics                                               -           ancestral characters

-         derived characters                                -           sister groups

-         stem group                                           -           clade

2.                  Using the phylogenetic tree that follows, provide names to the letters.  This is similar to Fig 2-1 in your text.  Use the following groups I have listed below.  Understand what each group name represents and what subsequent groups it gave rise to (where appropriate).  Groups to use include:  Sarcopterygii, fishes, Lysamphibia, diapsids, synapsida+mammals, ceacelians, turtles, reptilia, crocodiles, squamates, salamanders, amniotes, birds, therapsids,  tetrapods, frogs.

3.    Describe the functional and anatomical changes that occurred that are associated with the evolution from aquatic to terrestrial lifestyles.

4.    What am I talking about when I discuss Lissamphibia?  What are the shared derived characters associated with Lissamphibia? 

      5..    Why is the phylogenetic position of turtles controversial (e.g., why can’t we agree upon a phylogenetic hypothesis for this group)?

      6.           Is the above phylogentic tree monophyletic, polyphyletic, or paraphyletic? Why?