Heliconiaceae+Zingiberineae, finally leading to 2–5 staminodia dominating the floral display. The phylogenetic diversification and biogeographic dispersal of the Zingiberales was, in part, driven by the evolutionary radiation and diversification of their associated animal pollinators, which include bats, birds, non-flying mammals and insects. Six of the eight families of the Zingiberales contain taxa specialised for pollination by vertebrates, which appears to be the plesiomorphic state in the order. Of these six families two are exclusively vertebrate-pollinated (Strelitziaceae, Heliconiaceae). Pollination by insects also occurs in six families with one (Marantaceae) or possibly two (Lowiaceae) families predominantly specialised for insect visitors. Fossil record Seed and fruit fossils of the Zingiberales appear in the Santonian of the Late Cretaceous, ca. 85 Mya, and thought to represent Musaceae and Zingiberaceae, but the place of the oldest Zingiberales fossil, Spirematospermum with its distinctive seeds remains uncertain, but is most likely Zingiberaceae. The leaf fossil record for Zingiberales also extends back to the Late Cretaceous. Other fossil records include rhizomes and phytoliths. Diversity and biogeography The four families of the basal banana group exhibit less taxonomic diversity than the terminal ginger group. The three genera of Musaceae are distributed in tropical Asia and Africa, although fossil evidence reveals their presence in North America and Africa in the Tertiary, while the three genera of Strelitziaceae are allopatric (isolated from each other) being found in Madagascar, southern Africa and the Amazon Basin respectively and Lowiaceae occurs in Southeast Asia. The largest family in this group, the Heliconiaceae is primarily neotropical, but also occurs in the Pacific from Samoa to Sulawesi. Of the four Zingiberineae (gingers) families, three (Zingiberaceae, Costaceae, Marantaceae) are pantropical. The fourth, Cannaceae is restricted to the New World, although widely cultivated. This suborder contains the two largest families (Zingiberaceae and Marantaceae) and the largest number of species. Distribution and habitat Zingiberales are pantropical and occur predominantly in the wet tropical regions of Asia, Africa, and the Americas, occupying nearly all tropical wet lowlands or middle elevation forests as part of the understory flora. In addition five genera from three of the Zingiberineae families, including Canna extend into subtropical and temperate regions. Of the eight families, Heliconiaceae, Marantaceae, and Costaceae are predominantly neotropical and Zingiberaceae most prevalent in Southeast Asian wet understory habitats. These are mainly small to medium-sized herbaceous taxa or vines. While some herbaceous Zingiberaceae such as Alpinia boia can attain a height of ten