1) Aged 2) Fossilised 3) Inflexible 4) Old 1) Fossilised 2) Inflexible 3) Ossified 
• (a.) Converted into a fossil; antiquated; firmly fixed in views or opinions. • (imp. & p. p.) of Fossilize
Having been transformed into a fossil.
Fos'sil·ized adjective Converted into a fossil; antiquated; firmly fixed in views or opinions. « A fossilized sample of confused provincialism.» Earle. 
[adj] - set in a rigidly conventional pattern of behavior, habits, or beliefs
fossilised adjective set in a rigidly conventional pattern of behavior, habits, or beliefs; `obsolete fossilized ways`; `an ossified bureaucratic system`