Mahabharata 14.44.6

गायत्री छन्दसामादिः पशूनामज उच्यतेगावश्चतुष्पदामादिर्मनुष्याणां द्विजातयः

gāyatrī chandasāmādiḥ paśūnāmaja ucyategāvaścatuṣpadāmādirmanuṣyāṇāṃ dvijātayaḥ

Our plain-language meaning of this verse is waiting for scholar review.