Interested in human ancestry, e.g., primates, mammals, cynodonts, therapsids, synapsids, amniotes, tetrapods, etc.
Currently working on Synapsida (c. 325 mya) through Mammalia (c. 195 mya) of which only Mammalia is extant.

good article on taxonomy and cladistics:
Michael J. Benton Stems, nodes, crown clades, and rank-free lists: is Linnaeus dead?
Biol. Rev. (2000), 75,pp. 633-648 DOI: 10.1111/j.1469-185X.2000.tb00055.x