Family

A family is a taxonomic category that includes a group of related genera, showing less similarity between its members than is seen within a single genus or species. Families are useful precisely because they let taxonomists group several distinct-but-related genera together under one recognisable label, capturing a broader pattern of relatedness than the genus rank alone would show.

The textbook's worked example is the family Felidae, which includes both the genus Felis (small and medium-sized cats, such as the domestic cat, jungle cat and wild cat) and the genus Panthera (the big cats — lions, tigers and leopards). Although Felis and Panthera are distinct genera with real anatomical and behavioural differences (Panthera species can roar but not purr continuously, for example, while Felis species purr but cannot roar), both share the broader defining features of the cat family closely enough to be classified together at the family rank: they are all obligate ca …