In addition to the ICC conference, the BSG conference was held this week, so I'll be covering some of the talks given there throughout the week.
Kurt Wise gave an excellent presentation on one possible criteria for determining the extent to which mammalian (especially ark-based) baramins (a "Baramin" is a Genesis created kind - NOT equivalent to species) have diversified - the Post-Flood Continuity Criteria (PFCC), primarily based on data from the monograph Classification of Mammals, which had abundant data of the geological layers in which different mammalian organisms were found.
Kurt argued that the fossil record at the genus level for mammals is essentially complete, with some specific exceptions. Therefore, a given baramin should have a fossil record that goes all the way back to the flood, which, for this study, Kurt used the K/T boundary as the flood/post-flood boundary. Kurt argued from the data of the fossil record that, although we normally equate the baramin with the family as a first-pass approximation, many of these families do not go all the way back to the flood. However, if we extend this to the superfamily level, we often find extinct families which do go back to the flood. Kurt argued that these extinct organisms were the ancestors of the modern families of organisms.
Another interesting thing Kurt noted was that in order to go all the way back to the flood, you had to essentially connect all of Ruminantia to be part of the same baramin. What's even more interesting is that a friend had previously speculated just this very same thing to me on biological grounds (specifically, the uniqueness of the Ruminant stomach, and the fact that most of the other traits can be had by stretching/deforming basic morphologies). This would mean that cattle, deer, sheep, goats, and giraffes are all in the same baramin.
In any case, it is important (as Kurt emphasized) to keep in mind that baraminology is holistic, not reductionistic, and therefore no one criteria should be adopted for establishing baraminic continuity and discontinuity. Some of the issues with the post-flood continuity criteria are: