The Earliest-Known Stem  Mammals

DESCRIBER    Patterson & Olson, 1961
TIME    Jurassic Early
     Sinnemurian
CLASS    Mammalia (Linnaeus, 1785)
SUBCLASS    Incertea Sedis
ORDER    Incertea Sedis
FAMILY    Sinoconodontidea (Mills, 1971)
FOSSILSITE    Upper Red Beds. Lower Lufeng Formation, Yunnan, China
INFO

Sinoconodon rigneyi (Patterson & Olson, 1961) > Lufengoconodon changchiawaensis (Young, 1982) > Sinoconodon parringtoni (Young, 1982) and Sinoconodon yangi (Zhang & Cui, 1983)

Distinguished by a combination of characters, many of which are primitive among mammals. All specimens of Sinoconodon are from localities in close geographic proximity and at the same stratigraphic level (Stratum 6, Luo & Wu, 1994,1995)