I am wondering if there is any consensus on the structure terminology of the brain. 1 - I've heard that the brain has the reptilian, mammalian(limbic) and neocortex parts that overall perform specific functions and evolved in that order. - On that note, would reptiles have had any really poorly limbic or neocortex areas evolved, or would they have none of it? And also, do all animals (vertebrates or insects) have "reptilian" brains, or is what they have a brain "structure" that is pre-reptilian? 2 Secondly, I've also read about the separation terminology that divides the brain stem on one hand, and the cerebral cortex on the other. 3 - Finally I went to wikipedia and saw that there is another definition that the brain has three main parts: the cerebrum, the cerebellum and the brainstem. (this goes more along the second definition). - But it also says that the cerebrum includes the limbic system (which clashes with the first defintion). -It also says that all vertebrates have the cerebral cortex, which is the surface of the cerebrum (which would kind of clash with the reptilian brain only in reptiles, fish, etc, idea) - It also says that all mammals have the neocortex (two new definitions). Seems like the first definition seems to be a bit outdated, but I still hear many people talk about it as if it is part of the overall scientific agreement (or maybe I am mistaken?). Is there a easily illustrated definition that gives the latest consensus on where things are at with the brain and which animals have which parts of the part, and what functionalities, and furthermore, which parts of the brains evolved in what "order" (if this is even possible to know). Thanks for any thoughts!