Artemis Status
Be warned, because this one is gonna be spoiler-heavy. Artemis Status is an email from Charles Ronson to Elisabet Sobeck regarding, as you may have guessed, the status of the Artemis system.
If you missed this in the story, the Artemis system was essentially the way that the Old Ones managed to store fourteen thousand species’ samples that went extinct between the years 2000 and 2043.
Artemis Status also goes on to explain why you only seem to find a select few animals roaming around the world, and not elephants, giraffes or even dogs. This section reads as follows.
“We’ve started mapping out primary succession, selecting the pioneer organisms for a balanced and sustainable biosphere – microorganisms and insects, rabbits and hawks, foxes and wolves. Thousands more that will have to wait their turn until our new generation can be entrusted with the duty of restoring them.”
It may only be a tiny detail you notice as you explore the world, but it at least explains why some creatures can be seen happily roaming the world alongside the machines, and others still nowhere to be seen. Perhaps more species will be restored in the likely sequel.