Editing Monocotyledon (section)

====Core group====
The age of the core group of so-called 'nuclear monocots' or 'core monocots', which correspond to all orders except [[Acorales]] and Alismatales,{{sfn|Hedges|Kumar|2009|loc=[https://books.google.com/books?id=9rt1c1hl49MC&pg=PA205 p.&nbsp;205]}} is about 131 million years to present, and crown group age is about 126 million years to the present. The subsequent branching in this part of the tree (i.e. [[Petrosaviaceae]], [[Dioscoreales]] + Pandanales and [[Liliales]] clades appeared), including the crown [[Petrosaviaceae]] group may be in the period around 125–120 million years BC (about 111 million years so far{{sfn|Bremer|2000}}), and stem groups of all other orders, including [[Commelinidae]] would have diverged about or shortly after 115 million years.{{sfn|Janssen|Bremer|2004}} These and many clades within these orders may have originated in southern [[Gondwana]], i.e. Antarctica, Australasia, and southern South America.{{sfn|Bremer|Janssen|2006}}