Division of the genus Chryseobacterium: Observation of discontinuities in amino acid identity values, a possible consequence of major extinction events, guides transfer of nine species to the genus Epilithonimonas , eleven species to the genus Kaistella , and three species to the genus Halpernia gen. nov., with description of Kaistella daneshvariae sp. nov. and Epilithonimonas vandammei sp. nov. derived from clinical specimens

The genus in the family is known to be polyphyletic. Amino acid identity (AAI) values were calculated from whole-genome sequences of species of the genus 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 ( , , and ) to the genus and eleven ( , , , , , , , , and ) to the genus is proposed. Two novel species are described: sp. nov. and sp. nov. Evidence is presented to support the assignment of to a genus apart from to which comb nov. also belongs. The novel genus is proposed, to contain the type species comb. nov., along with comb. nov., and comb. nov.