Other than the Estemmenosuchus (which is not a Cenozoic animal), this looks like a really fantastic set.
I really wish I could support CollectA in particular. I love their artistic style and unique species choices. However, they would need to make much more original designs first as well as retool or stop production of many of their older figures. I've bought too many in the past only to discover an almost exact reference source later on. One of the main critiques I hear about this company is that their older models are much too out of date, so they really don't have much to lose by fixing this. Here's to hoping and praying they make the right decisions in the near future.