 A comprehensive phylogenetic analysis of oryzomyines by Marcelo Weksler, published in 2006, supported a close relationship among "Lundomys", "Holochilus", and "Pseudoryzomys"; the other species of the group were not included.Data from the sequence of the IRBP gene supported a closer relationship between "Holochilus" and "Pseudoryzomys", with "Lundomys" more distantly related, but morphological data placed "Holochilus" and "Lundomys" closer together, as did the combined analysis of both morphological and IRPB data.Subsequently, "Carletonomys cailoi" was described as an additional relative of "Holochilus" and "Lundomys".