First fossil record of the mayfly family Vietnamellidae (Insecta, Ephemeroptera) from Burmese Amber confirms its Oriental origin and gives new insights into its evolution

Burmella clypeata sp. nov., female imago, holotype A body, ventral view B, C apical part of abdomen, ventral view D basal segments of abdomen, dorsal view. I–III and V–IX – numbers of abdominal segments, gsr – remnant of gill socket, pp – paraproct plate. Scale bars: 1 mm (A); 0.5 mm (B–D).