An extinct juglandaceous fruit from the Upper Palaeocene of southern England

A new genus of juglandaceous winged fruit, is described from the Reading Beds (Upper Palaeocene) of southern England. It comprises one of the earlier macrofossil records of the Juglandaceae, and is the earliest from the European Tertiary. The fruit represents an extinct genus related to the extant tribe Engelhardieae, but excluded from it by its simple unlobed bract. Cladistic analysis shows Casholdia to display generalized engelhardioid fruit morphology. It lacks the tri-lobed bract diagnostic of the Engelhardieae, and predates the first occurrence of such bracts in the fossil record. Casholdia adds to the mounting evidence indicating an early Palaeogene radiation of the Juglandaceae.