mammals grew from synapsids, which were relations to diapsids from which the reptiles came from. So these two groups came after fish. https://bio.libretexts.o

mammals grew from synapsids, which were relations to diapsids from which the reptiles came from. So these two groups came after fish. https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/General_Biology_(Boundless)/29%3A_Vertebrates/29.03%3A_Amphibians/29.3C%3A_Evolution_of_Amniotes https://bio.libretexts.org/Bookshelves/Introductory_and_Gene...