[1] However, this is not the earliest clear evidence of hair in the mammalian lineage, as fossils of Volaticotherium,[2] and the docodont Castorocauda, discovered in rocks dated to about 164 million years ago, also have traces of fur.

[3] Eomaia scansoria possessed several features in common with placental mammals that distinguish them from metatherians, the group that includes modern marsupials.

[4] Eomaia, like other early mammals and living marsupials, had a narrow pelvic outlet suggesting small undeveloped neonates requiring extensive nurturing.

Monotremata Henkelotherium guimarotae Zhangheotherium quinquecuspidens Eomaia scansoria Theria The 2013 study by O'Leary et al. is part of a debate about the age of origin of placental mammals (see discussions.

Meng (2014),[12] who was a co-author on the O'Leary et al. (2013) paper, subsequently referred to Eomaia as a Eutherian but provided no analysis to support this claim.