Stylogomphus sigmastylus (Interior Least Clubtail):
Male exuviae - Newton County, Arkansas
dorsal view
ventral view
Showing distinctive Stylogomphus "spoon shaped" antennae, and tiny size

Cook, C., & E.L. Laudermilk, 2004, Stylogomphus sigmastylus sp. nov., a new North American dragonfly previously confused with S. albistylus (Odonata: Gomphidae), International Journal of Odonatology, 7(1):3-24
©Bob Barber, Jasper, Arkansas