if it doesn't make it to the right side then that branch is extinct(the synapsids going a bit past therapsids is on purpose)
Tiktaalik-the first tetrapod Anapsids-The first creatures to lay eggs with solid shells Synapsids-the ancestors of mammals and mammal like creatures Sauropsids-the ancestors of reptiles and birds Amphibians-a split from the tetrapods before anapsids Reptiles-you know what these are Birds-you know what these are Archosaurs-Dinosaurs, Pterosaurs, and crocodilians Therapsids-The ancestors of mammals, platypuses, and echidnas