Complex sentence: Both textual and archaeological evidence suggests Sati-Parvati appears in the epic period (400 BC--400 AD), as both the Ramayana and the Mahabharata present Parvati as Shiva's wife.
Split into simpler sentences: Both textual and archaeological evidence suggests Sati-Parvati appears in epic period (400 BC--400 AD). Both the Ramayana and the Mahabharata present Parvati as Shiva's wife.