In this task, you're given a statement, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.

Context: Anomocephaloidea is a clade (evolutionary grouping) of anomodont therapsids that existed in Gondwana during the Middle Permian Link Information: The Guadalupian is the second and middle series or epoch of the Permian. Previously called Middle Permian, the name of this epoch is part of a revision of Permian stratigraphy for standard global correlation. The name "Guadalupian" was first proposed in the early 1900s, and approved by the International Subcommission on Permian Stratigraphy in 1996.
References to the Middle Permian still exist. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains in New Mexico. The International Chronostratigraphic Chart (v2018/07) provides a numerical age of 272.3 ± 0.5 – 259.8 ± 0.4 Mya. Question: When did the time period in which Anomocephaloidea existed begin?
Answer: 272.3 ± 0.5 – 259.8 ± 0.4 Mya