So I've recently been delving into the history of creatures of this planet, and yes, everyone knows about dinosaurs and if you want to be good at creature design and anatomy it's good to not only look into present day creatures but also extinct species. But looking even further back into Earths past I've learnt about the precursors of dinosaurs, the Synapsids. I personally find these creatures incredibly interesting from what I've been able to find, but that's kind of the problem. They are so heavily overshadowed by Dinosaurs that any information seems to only pertain to their decline or how they're just a stepping stone of evolution, nothing showing a great deal of information about their evolution or physiology.
I guess what I'm asking is does anyone know where to find detailed information on this incredibly large (and important) class of animals? Books? Blogs? Websites? I'd just like to learn more and it's proving difficult.