MUSOPSIS N. GEN.: A BANANA-LIKE LEAF GENUS FROM THE EARLY TERTIARY OF EASTERN NORTH GREENLAND

A fossil flora from the Late Paleocene-Early Eocene Thyra Ø Formation of eastern North Greenland (paleolatitude 77° N) has yielded monocotyledon leaf impressions with characters seen only in the closely related modem species in the families of Heliconiaceae, Musaceae, and Strelitziaceae. The combination of large costae widths and parallel, nonanastomosing, lateral veins that depart at right angles from the costae in the fossil material are features present only in leaves of extant species from these families. Three basic venation patterns also are recognized in the modem species of these families, but except for the genera Strelitzia and Phenakospermum, none of these patterns are present exclusively in any one family. Musopsis n. gen. is created for the fossil material from Greenland, but it is considered a form genus due to the lack of gross morphological features that can be used for separating leaves of the modem genera in Heliconiaceae, Musaceae, and Strelitiziaceae. It is the first known Arctic occurrence of fossil leaf material resembling this modem group of taxa.