Towards Resolving the Interordinal Relationships of Placental Mammals

where.,Abstracts,to,talks,and,posters presented,at this meeting,can be found,at www.utexas.edu/ftp/depts/systbiol/. The talks fell into three main sections, which we will now consider, followed by a summary where,we present our current best estimate of the tree for placental mammals. The Age of Intraordinal Divergences Perhaps even,more,than,the tree of re- lationships, the ages molecular divergence times are suggesting,have,caused,greatest consternation,to morphologists.,Part of this seems to be semantics. For example, when some,authors,suggest,that perissodactyls originated well back in the late Cretaceous, it is not always,clear if they mean,the stem group Perissodactyla (i.e., all species more