Based on the methods outlined in Determining the Ark Kinds (Lightner et al. 2011), information on the class Mammalia was evaluated in an attempt to get a realistic estimate of what mammalian kinds would have been represented on the Ark. Examining information on extant species (those alive today), it was estimated that they represent 137 created kinds. Given the number of extinct mammalian families known from the fossil record, the actual number on the Ark could easily have been well over 300. This estimate is very low compared with those in the past. In evaluating the information, a number of important creationist research questions have been discussed. As further research is undertaken to address these, our knowledge of created kinds will be significantly advanced.