Then, the longest period of primates existence, since their apparition on the Cretaceous Period; in geologic time, the last of the three periods of the Mesozoic Era. The Cretaceous began 145.0 million years ago and ended 66 million years ago; it followed the Jurassic Period and was succeeded by the Paleogene Period (the first of the two periods into which the Tertiary Period was divided). The Cretaceous is the longest period of the Phanerozoic Eon. Spanning 79 million years, it represents more time than has elapsed since the extinction of the dinosaurs, which occurred at the end of the period.
But how can be understood that always the sapiens assume that all the human antecessors were mammals; what if there were reptilians or insects and so on through the zoo taxonomy ?