Ephemeroptera: Baetiscidae (Armored Mayflies)
- 3 pairs of jointed legs, each with a single claw; 3 tail-like filament with dense fringe on inside edges.
- 1 pair of wingpads apparent.
- Thorax developed into armorlike shield extending over abdominal segment 5.
- Body is stout.
Length: 4 mm to 14 mm
Peter Chen.