If the Purana written by Vyasa were still existing, then it would be honoured as a “Sruti”. In the absence of this Purana and the one written by Lomaharshana, the eighteen Puranas that still exist cannot all be given the same place of honour; among them, the Vishnu and the Bhagwata Purana composed by accomplished yogis are definitely more precious and we must recognise that the Markandeya Purana written by a sage devoted to spiritual pursuits is more profound in Knowledge than either the Shiva or the Agni Purana.
The Shiva Puranas are Shiva Purana, Linga Purana, Kurma Purana, Markandeya Purana, Skanda Purana, and Varaha Purana.
Markandeya Purana is that in which, commencing with the story of birds that were acquainted with right and wrong, everything is narrated fully by Markandeya, as it was explained by holy sages, in reply to the question of the Muni . It contains nine thousand verses, This is called from its being, in the first instance, narrated by Markendaya Muni, and, in the second instance place by certain fabulous birds.