Was the paterfamilias or dominant male was the head of the Roman family?

Yes- the head of a Roman Household was the Father of the House, known in Latin as the Paterfamilias. He was usually the husband and father, though the role could be taken by a grandfather, uncle, older brother or other older relative (or on occasions, a guardian whose position was sanctioned by Roman law). The Paterfamilias had responsibility for the upbringing of children, the family's pastoral and emotional welfare, the practicalities of running the household, and the finances & economy of the home. He was also expected to settle internal family disputes, and to keep an eye on the family's medical welfare. This responsibility extended to any servants or slaves that were employed, and also to any tenants or lodgers.