See Carleton and Musser (1984) for diagnosis, general characterisitics, habits, and habitat. The unique morphological adaptations of Lophiomys have always been recognized at either the family or subfamily level. Past estimates of phylogenetic relationships, or rather uncertainty, were expressed by arranging Lophiomys in its own family (Alston, 1876; Ellerman, 1941; Gill, 1872; Reig, 1981; Tullberg, 1899) or in a subfamily of either Muridae (Carleton and Musser, 1984; Musser and Carleton, 1993; Thomas, 1896; Weber, 1904; Winge, 1924), Cricetidae (G. M. Allen, 1939; Chaline et al., 1977; Corbet, 1978c; Miller and Gidley, 1918; Simpson, 1945), or Nesomyidae (Lavocat, 1973).
Lavocat (1973) regarded Lophiomys as a possible derivative from the Miocene Afrocricetodontinae. Wahlert (1984) postulated a close phylogenetic alliance, based upon dental morphology, between Lophiomys and Cricetops dormitor from the early Oligocene of Mongolia and Kazakhstan, allocated both to Lophiomyinae, and considered the subfamily closely related to Cricetinae. Close relationship between Lophiomys and Cricetops has been disproven (Carrasco and Wahlert, 1999), and Cricetops and the early Miocene Enginia from Turkey are now placed in the Cricetopsinae (McKenna and Bell, 1997), excluding Lophiomys. The independent acquisition of dental similarities between extant Lophiomys and Cricetops is indicated by lophiomyine fossils from Spain and Morocco. Protolophiomys ibericus, late Miocene of S Spain (Aguilar and Thaler, 1987), combines some primitive cranial and dental states with the peculiar pebble-textured cranium like extant Lophiomys, and this combination also characterizes Lophiomys maroccanus from the Pliocene of Morocco (Aguilar and Michaux, 1989-1990). Moroccan sediments have also yielded isolated molars identified as Lophiomys sp. from Miocene-Pliocene (Geraads, 1998) and Pliocene-Pleistocene sediments (Aguilar and Michaux, 1989-1990).
Although extant Lophiomys have complex molars (Wahlert, 1984), they are less so in the extinct forms, which resemble Miocene cricetids such as Megacricetodon and Democricetodon. The latter first appears in early Miocene sediments of Europe, is among the most common cricetids uncovered in the middle Miocene, and is regarded as the ancestor for many later generic lineages (Kälin, 1999). Democricetodon has also been documented in the middle Miocene of East Africa, and Tong and Jaeger (1993) speculated that it represents the African ancestor of Lophiomys. Whether derived from an African or European ancestral stock, available dental evidence links Lophiomys with cricetids, not nesomyids, possibly originating from an ancestor resembling Democricetodon (Carleton and Musser, 1984; Tong and Jaeger, 1993). A test of this hypothesis with broader cladistic analyses of other information bases is welcomed.
Topachevskii and Skorik (1984) described Microlophiomys, based upon isolated first upper and lower molars recovered from late Miocene sediments in Ukraine, as a member of Lophiomyinae. Its elaborate occlusal surfaces recall those of extant Lophiomys, but no other evidence so far confirms its allocation to the subfamily. The M1 (but not m1) also resembles that of extant Mesocricetus, and considering the spectacular parallelism in dental patterns among cricetids, one could interpret Microlophiomys as a derived form more closely related to Eurasian cricetines.