It is well known that of the two Puranas – Devi Bhãgavata and Sri Bhagavata, the Saktas and Vaisnavas claim that their own sectarian work is the real Mahapurana composed by Vyasa and the other is a mere Upapurana. In his introduction to the Devi – Bhagavata, Nilakantha asserts that the authority of the Matsya and Saiva Puranas is in favour of the priority of Devi Bhagavata. He quotes the following verses in support.

Bhagavatyas ca Durgayas caritam yatra vidyate
Tattu Bhagavatam proktam na tu Devipuranakam
(Saiva – Madhyesyara mahatmye)

Here Devipuranaka means the Upapurana Kalika Purana
yadidam Kalikakhyam tanmulam Bhagavatam smrtam
(Hemadrsu)

The chief characteristics of Bhagavata are these enumerated in the Matsya: -
यत्राधिकृत्य गयात्रीम् वर्णयते धर्मविस्तर |
वृत्रासुरवधोपेतं तभ्दागवतमिष्यते ||
सारस्वतस्य कल्पस्य मद्ये ये स्युर्नरामरा: |
तद्वत्तान्तोभ्दबं लोके तभ्दागवतमिष्यते ||

Puranantare: -
हयग्रीवब्रह्मविध्या यत्र वृत्रवधस्तथा |
गायत्र्या च स्मारम्भस्तद्वै भागवतं विदु: ||

Thus, the Bhagavata is that work which commences with Gayatri and deals extensively with Dharma, and the story of the killing of Vrtra, in the Sarasvata kalpa, and Hayagriva Brahmavidya. All these are only applicable to the Devi Bhagavata which begins with this mantra.