Zyzomys Thomas 1909

Zyzomys Thomas 1909, Ann. Mag. Nat. Hist., ser. 8, 3: 372.

Type Species: Mus argurus Thomas 1889

Synonyms: Laomys Thomas 1909 .

Species and subspecies: 5 species:

Species Zyzomys argurus (Thomas 1889)

Species Zyzomys maini Kitchener 1989

Species Zyzomys palatilis Kitchener 1989

Species Zyzomys pedunculatus (Waite 1896)

Species Zyzomys woodwardi Thomas 1909

Discussion: Pseudomys Division. Member of the Australian Old Endemics (Musser, 1981 c) or Conilurini of Baverstock (1984) and Lee et al. (1981), or Hydromyini of Baverstock and Watts (1994 a). Taxonomy of species appraised by Kitchener (1989). Chromosomal morphology distinct from other Australian murines (Baverstock et al., 1977 c), but not allozymic data (Baverstock et al., 1981), and G-banding homologies suggested karyotype of Zyzomys "to be derived from the ancestral karyotype characterizing Conilurus, Mesembriomys, and Leggadina " (Baverstock et al., 1983 b). Molar traits resemble those characterizing Conilurus (Misonne, 1969), but phallic characters link Zyzomys to Pseudomys and its close relatives (Lidicker and Brylski, 1987). Albumin immunology indicates Zyzomys belongs in a clade with Mesembriomys, Conilurus, Leporillus, and Melomys (Watts et al., 1992), and Watts and Baverstock (1994 a, 1995 b, 1996) included it in their expanded version of Hydromyini (an "Australasian clade"), which incorporates the former Conilurini. External morphology of glans penis and spermatozoa reported by Breed (1984), Breed and Sarafis (1978), and Morrissey and Breed (1982), and phylogenetic significance discussed by Breed (1997). Mahoney and Richardson (1988) cataloged taxonomic, distributional, and biological references to some of the species. Zyzomys rackhami, the earliest record of the genus, comes from late Pliocene sediments (Aplin, 2004; Godthelp, 1997).