 However, the family did not diverge into its extant subfamilies until 19 million years ago.The long period between the origin and diversification of bromeliads, during which no extant species evolved, suggests that there was much speciation and extinction during that time, which would explain the genetic distance of the Bromeliaceae from other families within the Poales.The most basal genus, "Brocchinia", is endemic to the Guiana Shield, and is placed as the sister group to the remaining genera in the family.