(Figs 4, 7, 9)
Holotype. Male. ECUADOR: Pastaza: 25 km N Puyo, 1.2855°S 78.02291°W, 1000 m, 13 Jul 1976, S. B. Peck, 1♂ (UCR _ ENT 00090642) (FMNH).
Paratypes: ECUADOR: Pastaza: Pastaza, 1.43583°S 78.00194°W, 972m, 13 Jul 1976, S. B. Peck, 4♂ (UCR _ ENT 00090643 -UCR_ENT 00090646) (FMNH).
Etymology: Named for the long ridge-like process on the anophoric after “tergus” Latin for ridge (noun in apposition).
Diagnosis: Recognized by the very small body length (0.67 mm), small vein-tracing areoles along rc and rc1 (black arrow) (Fig. 4), almost full-loop, circular vesica, and long anophoric process with curved single tip (black arrow) (Fig. 7).
Description: Male: Total body length 0.67 mm; length from posterior margin of pronotum to posterior wing margin 0.52 mm; greatest width across pronotum 0.28 mm; greatest width across forewings 0.42 mm. General coloration: mix of pale and darker brown or reddish brown. Vestiture: Dorsum with sparse setae, setae short; setae on posterior margin of forewing long. Structure: Head: Eye almost half as high as head; muscle scars large.
Thorax: Anterior pronotal margin concave, posterior margin slightly concave; pits on pronotum medium-sized, evenly distributed; scutellum in dorsal view abruptly narrowed to tip, tip pointed. Forewing: With outline broad anteriorly; membrane contributing about one third of forewing length, posterior distal margin squarish, vein-tracing areoles small, distributed along rc and rc1; C+Sc fairly narrow, wider at widest part of wing; distal process of R pronounced; An1 wing organ on corium strongly inflated, rounded, with median notch, without notch articulating with claval process; rc1 about 3 times as long as wide, much wider anteriorly; rc about 4 times as long as wide; tc about 3 times as long as wide; part of An1 and Cu forming posterodistal margin of tc of similar width as other veins; distal margin of rc1, rc, and tc cells double s-shaped; rc2–3 trapezoidal; cub almost reaching wing margin; dc1 horse head-shaped. Legs: Claws long. Genitalia (Fig. 7): Pygophore without lobe on right side; vesica with between half and one loop, not reaching right pygophore margin, thick at midpoint, tapering to acute tip, close to apex rounded; anophoric ridge with process, process long, with single lobe curved, tip pointed; right paramere curved, broad throughout, basal process narrow; left paramere straight, broad throughout, basal process narrow.
Female: Unknown.
Collecting method and habitat: Collected using Berlese extraction in cloud forest litter.