Nyctomys Saussure 1860

Wilson, Don E. & Reeder, DeeAnn, 2005, Order Rodentia - Family Cricetidae, Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 2, Baltimore: The Johns Hopkins University Press, pp. 955-1189 : 1187

Nyctomys Saussure 1860

Nyctomys Saussure 1860 , Rev. Mag. Zool. Paris, ser. 2, 12: 106.

Type Species: Hesperomys sumichrasti Saussure 1860

Species and subspecies: 1 species:

Species Nyctomys sumichrasti Saussure 1860

Discussion: Nyctomyini new tribe. Type genus— Nyctomys Saussure, 1860 . Definition—Medium-sized tylomyine rodents with rich tawny to reddish-brown pelage, tail densely furred and noticeably penicillate; cranium with short, stocky rostrum and arched dorsal profile; jugal thin but a constant middle element of zygomatic arch; carotid circulation complete ( Otonyctomys ) or derived (most Nyctomys ); basihyal with small, knobby entoglossal process; vertebral column with 13 thoracics and 6 lumbars ( Carleton, 1980); M1 oval, anterocone narrow and undivided, M3 ovate, smaller than M2; two complete and five incomplete transverse palatal ridges ( Carleton, 1980); accessory reproductive glands with two pairs of preputials, ampullaries loose and filiform, dorsal prostates strongly modified, anterior prostates and vesiculars absent ( Voss and Linzey, 1981); glans penis with urethral process and dorsal papilla ( Hooper and Musser, 1964 a). Contents— Nyctomys Saussure, 1860 ; Otonyctomys Anthony, 1932 .

Placed with thomasomyine group by Hershkovitz (1944, 1962, 1966 c) based on its pentalophodont molars and short-wide palate. Numerous studies have supported removal of Nyctomys from thomasomyines proper and even questioned its placement within Sigmodontinae sensu stricto ( Arata, 1964; Carleton, 1980; Haiduk et al., 1988; Hooper and Musser, 1964 a; Steppan, 1995; Voss and Linzey, 1981). Phylogenetic interpretation of mitochondrial DNA sequences also suggest an ancient New World lineage, basal to Sigmodontinae or to Cricetinae-Sigmodontinae depending upon the trees generated ( Engel et al., 1998) .