Order Rodentia - Family Muridae Author Wilson, Don E. Author Reeder, DeeAnn text 2005 The Johns Hopkins University Press Baltimore Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 2 1189 1531 book chapter 0-8018-8221-4 10.5281/zenodo.7316535 Rattus colletti Thomas 1904 Rattus colletti Thomas 1904 , Novit. Zool., 11: 599 . Type Locality: Australia , Northern Territory , South Alligator River (see Mahoney and Richardson, 1988 ). Vernacular Names: Australian Dusky Rat . Distribution: Australia ; known only from the coastal floodplains of the Northern Territory , the most restricted range of all the native Australian Rattus ( Watts and Aslin, 1981 ; Williams, 1995). Conservation: IUCN – Lower Risk (lc). Discussion: Rattus fuscipes species group. Arranged as a subspecies of R. sordidus by Taylor and Horner (1973) , but subsequently treated as a separate species ( Mahoney and Richardson, 1988 ; Watts and Aslin, 1981 ; Williams, 1995). Although diploid counts are very different, Rattus colletti (2n = 42) is genetically very close to R. villosissimus (2n = 50); the two hybridize in the laboratory, but the offspring exhibit severely reduced fertility ( Baverstock et al., 1983 a , 1986). An undescribed species related to R. colletti and R. villosissimus is known from a small area in C Queensland (Aplin, in litt., 2004). Fertile hybrids have also been obtained between laboratory crosses of R. colletti and R. tunneyi ( Baverstock et al., 1983 a ) .