More ignorance.
One thing noted by evolutionists is that during the time of dinosaur hegemony, mammals were mostly small, and had physiologies for hunting and digesting insects.
It wasn’t until dinosaurs were gone that mammals started to get bigger, and eat things other than insects.
Various branches of mammals have maintained to, various levels of completeness, the genes required to digest the tough body armor of most insects. There are 5 major kinds of genes for digesting insect body armor. (I can’t recall the technical term for this material.) Interestingly enough, humans actually still retain one of these 5 genes.
What’s my point?
In Evolution, “kinds” don’t just willy nilly differentiate into all possibilities. They can only differentiate and SURVIVE when other species and animal groupings don’t already occupy a niche better than a newcomer group would.
Mammals just DONT become big during the DINO age. Whenever one started to get bigger, dinosaurs eventually would notice them better and hunt them to extinction. Mammals never got bigger than about a badger, but most were shrew-like and shrew-sized.
Why don’t fish continue to evolve into new kinds of tetrapods? Because the descendants of the original tetrapods are brilliant at killing anything flopping around on the shoreline.
And so on.