It could be a convenient shorthand to suggest this was a timeline where the meteorite never struck and the long reign of the dinosaurs simply continued beyond the traditional boundaries of the Cretaceous, never knowing the narrow escape it had. Convenient, but untrue. That asteroid is out there in every timeline, set in motion at the start of all things. Barring a powerful presence in space when this rock reaches Earth, no efforts by this species or that will deflect it. But—although I might see some dinosaurs at the back begging to differ—that impact is no great dying time. Of the Earths we have seen who survived the Permian extinction, all weather the Chicxulub impact, to various degrees. It is a time of tragedy and loss, on a scale impossible for us to conceive. However, we are looking at these timelines from the privileged viewpoint of sixty-five million years later. That gives us a certain hard perspective. In this timeline, most of the dinosaurs on this Earth died, it’s true, as did an awful lot of other things, yet a handful of dinosaur species lived. A few small therapod carnivores, ones that ferreted mammals from their burrows to snack on through the long dark years of dust and cold; a dwarf sauropod whose island habitat had already forced it to live on moss and lichen and for whom the impact made a virtue of former necessity; the odd maverick species whose hard pasts had led them to evolve the capacity to hibernate through the bad years. The iron hold of the terrible lizards was pried from the throat of the world in the wake of the impact, but they clung on. And when the skies cleared, there they were, ready to take up their mantle.

In this timeline, the Earth hosts a diverse biosphere by now. Mammals have prospered and grown large, scurrying gleefully into the various niches vacated by vanished lineages of saurians. The nimble birds have diversified into a variety of airborne and flightless forms. But alongside these are the hunters we have met, and a scattering of other dinosaur descendants making the best of a more egalitarian world.