The Earliest-Known Stem  Mammals

DESCRIBER    Jenkins et al., 1983
TIME    Jurassic Early
Sinemurian
CLASS    Mammalia
SUBCLASS    Incertae Sedis
ORDER    Morganucodonta (Kermack, et al., 1973)
FAMILY    Megazostrodontidae (Gow, 1986)
FOSSILSITE    Kayenta Formation, Gold Springs, Arizona, United States
INFO
Typespecies by monotype. Known from denteries with complete dentition and upper premolars and molars, plus disarticulated baiscranial elements.