This is extracted from one of Alexis Sanderson’s articles
A lot of Pāśupata Śāstras existed(apart from the famous sutra) which had the suffix -pramāṇa. The Pramāṇas dealing with ritual were formulated by Musalendra based on the Hṛdayapramāṇa.They are:
The Hṛdayapramāṇa itself was a part of a set of ‘pramāṇa’śastras,and this second set was concerned with gnosis(and not ritual) and were deemed to be superior śāstras. They were:
This listing of Pāśupata śāstras is done by Kṣemarāja who notes the various Rudras who take on the names of these śāstras.