The Earliest-Known Stem  Mammals

DESCRIBER    Kühne, 1949
TIME    Triassic Late, Jurassic Early, Jurassic Middle
CLASS    Mammalia
SUBCLASS    Incertae Sedis
ORDER    Morganucodonta (Kermack, et al., 1973)
FAMILY    Morganucodontidae (Kühne, 1958)
FOSSILSITE    

Morganucodon is known from Britain, Belgium, Luxembourg, France, Germany, Switserland (LT > JM) India (LT>JE) Greenland (LT), China (JE), South Africa (JE) Arizona (JE)

Lorraine (Sint-Nicolas-de-port, Varangéville) France [Triassic Late (?Rhaetian)] ?M. watsoni

Kanton Schaffhausen, Hallau bonebed, Switserland [Triassic Late (Rhaetian)] M. peyeri

Fissure fillings, Glamorgan, St. Bride Island, Pant Quarry, Britain, Wales [Jurassic Early (\"Liassic,\" ?Sinemurian)] M. watsoni [Undescribed large morganucodontid]

Lower Lufeng Formation, Yunnan, China [Jurassic Early (\"Liassic,\" ?Sinemurian)] M. oehleri , M. heikuopengensis, these two Chinese species are clearly more derived taxa whitin the Morganucodon clade (Luo & Wu, 1994, 1995)

Kayenta Formation, Gold Springs, Arizona, United States [Jurassic Early (\"Liassic,\" ?Sinemurian)] Morganucodon sp.
INFO

Morganucodon watsoni (Kühne, 1949) > Morganucodon oehleri (Rigney, 1963) > Morganucodon heikuopengensis (Young, 1978) > Morganucodon peyeri (Clemens,1980) > Morganucodon sp., (Jenkins et al., 1983)

Morganucodon is the most completely known genus of the family Morganucodontidae.

Morganucodon watsoni (Kühne, 1949) [refered by some authors as Eozostrodon watsoni]

Morganucodon heikuopengensis (Young, 1978) [originally described as Eozostrodon heikuopengensis]