The genus
Chryseobacterium
in the family Weeksellaceae is known to be polyphyletic. Amino acid identity (AAI) values were calculated from whole-genome sequences of species of the genus Chryseobacterium, and their distribution was found to be multi-modal. These naturally-occurring non-continuities were leveraged to standardise genus assignment of these species. We speculate that this multi-modal distribution is a consequence of loss of biodiversity during major extinction events, leading to the concept that a bacterial genus corresponds to a set of species that diversified since the Permian extinction. Transfer of nine species (
Chryseobacterium arachidiradicis
,
Chryseobacterium bovis
,
Chryseobacterium caeni
,
Chryseobacterium hispanicum
,
Chryseobacterium hominis
,
Chryseobacterium hungaricum
ï»ż,
Chryseobacterium molle
,
Chryseobacterium
pallidum
and
Chryseobacterium zeae
) to the genus
Epilithonimonas
and eleven (
Chryseobacterium anthropi
,
Chryseobacterium antarcticum
,
Chryseobacterium carnis
,
Chryseobacterium chaponense
, Chryseobacterium haifense, Chryseobacterium jeonii,
Chryseobacterium montanum
,
Chryseobacterium palustre
,
Chryseobacterium solincola
,
Chryseobacterium treverense
and
Chryseobacterium yonginense
) to the genus
Kaistella
is proposed. Two novel species are described: Kaistella daneshvariae sp. nov. and Epilithonimonas vandammei sp. nov. Evidence is presented to support the assignment of
Planobacterium taklimakanense
to a genus apart from Chryseobacterium, to which Planobacterium salipaludis comb nov. also belongs. The novel genus Halpernia is proposed, to contain the type species Halpernia frigidisoli comb. nov., along with Halpernia humi comb. nov., and Halpernia marina comb. nov.