Editing Squirrel monkey (section)

=== Evolution ===
The crown group of the extant squirrel monkeys appears to have diverged around 1.5 million years ago.<ref name="Chiou2011">{{cite journal|title= Pleistocene diversification of living squirrel monkeys (''Saimiri'' spp.) inferred from complete mitochondrial genome sequences|year=2011|pmid=21443955|last1=Chiou|first1=K. L.|last2=Pozzi|first2=L.|last3=Lynch Alfaro|first3=J. W.|last4=Di Fiore|first4=A.|journal=Molecular Phylogenetics and Evolution|volume=59|issue=3|pages=736–45|doi=10.1016/j.ympev.2011.03.025|bibcode=2011MolPE..59..736C }}</ref> Diversification of squirrel monkey species appears to have occurred during the [[Pleistocene]] Epoch, likely due to climatic changes associated with interglacial periods in South America at the time. The origin of squirrel monkeys in Central America is unclear, but a possible hypothesis is human transport. More genetic work needs to be done on the subject to reveal a true answer.<ref name="Chiou2011" />''S. boliviensis'' appears to be the first diverging species in the group. ''S. oerstedii'' and ''S. s. sciureus,'' are sister species. ''S. s. macrodon'' is the sister species to the ''S. oerstedii'' / ''S. s. sciureus'' clade.{{clarify|date=February 2016}}<!--By definition, "S. s. sciureus" & "S. s. macrodon" are both subspecies of "S. sciureus"!-->