IPA: /kəʊˈiːvəli/
KK: /koʊˈiːvəli/
In a way that indicates two or more things exist or occur at the same time or during the same period.
The two species evolved coevally, adapting to their shared environment.
Coevally → It is formed from "co-" (meaning together) and "aevus" (meaning age or era), combined with the adverbial suffix "-ly" (meaning in a manner). The word "coevally" means in a manner that relates to or exists at the same time or age as something else.
Think of 'together' ('co-') and 'age' ('aevus') to remember that 'coevally' refers to things that exist at the same time.