Ūrdhvavāhu (Urdhvavahu) is one of the sons born of the womb of Ūrjjā (urjja), sired by Sage Vaśiṣṭha (Vasistha). In Raivata Manvantara, when Vibhu became Indra, Ūrdhvavāhu was one of the Saptarṣi (Saptarshi; the legendary seven sages hailed in ancient mythology).

Bhāgavatpurāṇa Vols. 1-12(8.5.3)
Brahmāṇḍapurāṇa (Maharṣi)(1.11.41; 1.36.62)
Viṣṇupurāṇa(1.10.3; 3.1.22)
Vāyupurāṇa(62.53-54)
Garuḍapurāṇa(1.5.15)
Kūrmapurāṇa(1.13.13)
Brahmapurāṇa (Beng.)(5.25)
Mārkaṇḍeyapurāṇa(52.25; 75.73)
Śivapurāṇa((Vāyavīya) 15.34-36)