[5] Such a drastic size increase compared to its North America cousins likely stems from a rapid evolutionary response upon arriving in South America, with Chapalmalania evolving from the "dog-coati" Cyonasua, which probably island-hopped from Central America during the late Miocene (7.5 million years ago), making them perhaps the earliest southward mammalian migrants of the Great American Interchange, and one of the few documented cases of trans-oceanic dispersals of carnivores mammals (the only other major examples being the Eupleridae of Madagascar and the Sulawesi palm civet of Sulawesi).

It is thought the reason for this comes down to various aspects of procyonid biology that grant higher success at dispersing across ocean barriers than other carnivores.

Secondly, their omnivorous diet allows them to take advantage of more food options when stranded out to sea, extending their survival and thus increasing their chances of making it to land.

It is thought that as the Isthmus of Panama rose from the sea to allow further invasions by other North American species, Chapalmalania was unable to compete and its lineage became extinct, especially with the arrival of Tremarctinae bears which appear to share similar dental morphologies with the large procyonid.

[7] However, it is also possible the extinction of Chapalmalania was due to climatic changes that occurred during the Pleistocene that wiped out a number of the continent's native fauna (Such as the large terror birds like Titanis, megafaunal members of Dinomyidae, and various South American native ungulates), with bears filling in the empty niches upon their arrival to the continent during the Late Uquian.