All lineages go back to the time of dinosaurs and earlier. (Ultimately they all appear to converge on the last common ancestor) Any species tend to only last f

All lineages go back to the time of dinosaurs and earlier. (Ultimately they all appear to converge on the last common ancestor) Any species tend to only last for 1-2 million years. If they don’t go extinct, they give rise to one more more descendant species. This produces a chain of ancestry where species give birth to more species. Sharks, as a group, certainly arose before the time of dinosaurs. The current species of sharks evolved recently from earlier species of sharks. There were multiple groups of reptiles prior to the time of the dinosaurs. Some of those reptiles produced descendants that later became mammals. Some of those reptiles produced descendants that became crocodiles, turtles, and dinosaurs. Humans, as mammals descended from those early mammals that first appeared before the “age of dinosaurs”. Mammals lived alongside dinosaurs for hundreds of millions of years. When the dinosaurs went extinct, the global disruption that cause that extinction removed most of the species living at that time. The survivors then found room to evolve into new niches in the ecologies as those ecologies recovered. Reptiles like the ancestors of modern crocodiles survived. Birds were the only group of dinosaur to survive and chickens and parrots are modern examples of that bird group. The mammals that survived evolved into newly opened up ecological niches and many lineages branched out from those survivors. The primates, including humans, were one such group. I hope that this, high level summary, helps clear things up a little for you.