SETITHECA LATIVALVA GEN. ET SP. NOV., A FOSSIL FLOWER OF LAURALES FROM MID-CRETACEOUS MYANMAR AMBER

摘要

A single staminate flower preserved in mid-Cretaceous Myanmar amber is described as Setitheca lativalva gen. et sp. nov. The fossil's affinities appear to be with Monimiaceae and allied families of order Laurales. Jiie perianth is composed of ca. 12 spirally arranged tepals of varying size and shape. A single whorl of 10 stamens is attached to the margin of a flat central disc. There is no gynoecium. In some of the stamens, the bilocular anthers are held upright, but in the others, the filaments arearched abaxiallyand the anthers are reflexed. Dehiscence is extrorse via 2 lateral, dorsally-hinged valves, as also occurs in some members of Hernandiaceae. The spherical pollen appears to be inap-erturate. Such features as the unisexual flowers, valvateanthers, and a perianth of numerous, spirally arranged tepals are consistent with assignment of the fossil to this order of angiosperms.