Śrīla Viśvanātha Cakravartī Ṭhākura gives the meaning of dvi jātayaḥ as "mixed caste," indicating a mixture of brāhmaṇa and kṣatriya.
Having been born from the womb of Rathitara's wife, all these sons were known as the dynasty of Rathitara, but because they were born from the semen of Angira, they were also known as the dynasty of Angira
Expressions researched:
"Having been born from the womb of Rathītara's wife, all these sons were known as the dynasty of Rathītara, but because they were born from the semen of Aṅgirā, they were also known as the dynasty of Aṅgirā"
Srimad-Bhagavatam
SB Canto 9
Having been born from the womb of Rathītara's wife, all these sons were known as the dynasty of Rathītara, but because they were born from the semen of Aṅgirā, they were also known as the dynasty of Aṅgirā. Among all the progeny of Rathītara, these sons were the most prominent because, owing to their birth, they were considered brāhmaṇas.
Having been born from the womb of Rathītara's wife, all these sons were known as the dynasty of Rathītara, but because they were born from the semen of Aṅgirā, they were also known as the dynasty of Aṅgirā. Among all the progeny of Rathītara, these sons were the most prominent because, owing to their birth, they were considered brāhmaṇas.