| fossil_range = [[Paleocene]]-[[Holocene]] {{fossilrange|66|0|earliest=120}} <small>Diperkirakan, awal [[Cretaceous]]<ref>{{Cite journal |pmc = 298725|year = 2003|last1 = Springer|first1 = M. S.|title = Placental mammal diversification and the Cretaceous–Tertiary boundary|journal = Proceedings of the National Academy of Sciences of the United States of America|volume = 100|issue = 3|pages = 1056–1061|last2 = Murphy|first2 = W. J.|last3 = Eizirik|first3 = E.|last4 = O'Brien|first4 = S. J.|pmid = 12552136|doi = 10.1073/pnas.0334222100}}</ref><ref>{{Cite journal |pmc = 2655268|year = 2009|last1 = Nishihara|first1 = H.|title = Retroposon analysis and recent geological data suggest near-simultaneous divergence of the three superorders of mammals|journal = Proceedings of the National Academy of Sciences of the United States of America|volume = 106|issue = 13|pages = 5235–5240|last2 = Maruyama|first2 = S.|last3 = Okada|first3 = N.|pmid = 19286970|doi = 10.1073/pnas.0809297106}}</ref><ref name="Reis, M. 2012">{{cite journal | last1 = dos Reis | first1 = M. | last2 = Inoue | first2 = J. | last3 = Hasegawa | first3 = M. | last4 = Asher | first4 = R.J. | last5 = Donoghue | first5 = P.C.J. | last6 = Yang | first6 = Z. | year = 2012 | title = Phylogenomic datasets provide both precision and accuracy in estimating the timescale of placental mammal phylogeny | journal = Proceedings of the Royal Society B | volume = 279 | issue = 1742| pages = 3491–3500 | doi=10.1098/rspb.2012.0683 | pmid=22628470 | pmc=3396900}}</ref></small>
'''Placentalia''' adalah salah satu hewan yang masih ada pada golongan [[Mammalia]]; dua lainnya yaitu [[Monotremata]] dan [[Marsupial]]. Kelompok ini terkadang disalahnamakan karena hewan marsupial juga memberi makanmenutrisi [[fetus]] mereka viamelalui [[plasenta]],.<ref name="Renfree2010">{{cite journal | author=Renfree, M.B. | title=Review: Marsupials: placental mammals with a difference | journal=Placenta | volume=31 Supplement | pages=S21–6 | date=March 2010 | doi=10.1016/j.placenta.2009.12.023 | pmid= 20079531 }}</ref>
