TimeTree is a public knowledge-base for information on the evolutionary timescale of life. A search utility allows exploration of the thousands of divergence times among organisms in the published literature. A tree-based (hierarchical) system is used to identify all published molecular time estimates bearing on the divergence of two chosen taxa, such as species, compute summary statistics, and present the results.
You can type in some species names (or common names) and get an approximation of when those two species initially diverged!
Humans split from dogs ~97 mya.
Humans split from cats ~97 mya.
Dogs split from cats ~58 mya.
So we split from dogs and cats, before dogs and cats diverged from one another!